Fix wasm builds

Use dedicated warnings for flake8-to-ruff (#1748 )
Add support for defining extra builtins (#1747 )
2023-01-09 12:58:07 -05:00 · 2023-01-09 12:48:06 -05:00 · 2023-01-09 12:24:28 -05:00 · 2023-01-09 01:39:51 -05:00 · 2023-01-09 01:14:28 -05:00 · 2023-01-09 01:06:48 -05:00
539 changed files with 21965 additions and 16303 deletions
--- a/.github/CODE_OF_CONDUCT.md
+++ b/.github/CODE_OF_CONDUCT.md
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -56,33 +56,35 @@ prior to merging.

 There are four phases to adding a new lint rule:

-1. Define the rule in `src/registry.rs`.
-2. Define the _logic_ for triggering the rule in `src/checkers/ast.rs` (for AST-based checks),
+1. Define the violation in `src/violations.rs` (e.g., `ModuleImportNotAtTopOfFile`).
+2. Map the violation to a code in `src/registry.rs` (e.g., `E402`).
+3. Define the _logic_ for triggering the violation in `src/checkers/ast.rs` (for AST-based checks),
   `src/checkers/tokens.rs` (for token-based checks), or `src/checkers/lines.rs` (for text-based checks).
-3. Add a test fixture.
-4. Update the generated files (documentation and generated code).
+4. Add a test fixture.
+5. Update the generated files (documentation and generated code).

-To define the rule, open up `src/registry.rs`. You'll need to define both a `CheckCode` and
-`CheckKind`. As an example, you can grep for `E402` and `ModuleImportNotAtTopOfFile`, and follow the
-pattern implemented therein.
+To define the violation, open up `src/violations.rs`, and define a new struct using the
+`define_violation!` macro. There are plenty of examples in that file, so feel free to pattern-match
+against the existing structs.

-To trigger the rule, you'll likely want to augment the logic in `src/checkers/ast.rs`, which defines
-the Python AST visitor, responsible for iterating over the abstract syntax tree and collecting
-lint-rule violations as it goes. If you need to inspect the AST, you can run
-`cargo +nightly dev print-ast` with a Python file. Grep for the `Check::new` invocations to
-understand how other, similar rules are implemented.
+To trigger the violation, you'll likely want to augment the logic in `src/checkers/ast.rs`, which
+defines the Python AST visitor, responsible for iterating over the abstract syntax tree and
+collecting diagnostics as it goes.
+
+If you need to inspect the AST, you can run `cargo +nightly dev print-ast` with a Python file. Grep
+for the `Check::new` invocations to understand how other, similar rules are implemented.

 To add a test fixture, create a file under `resources/test/fixtures/[plugin-name]`, named to match
-the `CheckCode` you defined earlier (e.g., `E402.py`). This file should contain a variety of
+the code you defined earlier (e.g., `E402.py`). This file should contain a variety of
 violations and non-violations designed to evaluate and demonstrate the behavior of your lint rule.

 Run `cargo +nightly dev generate-all` to generate the code for your new fixture. Then run Ruff
 locally with (e.g.) `cargo run resources/test/fixtures/pycodestyle/E402.py --no-cache --select E402`.

 Once you're satisfied with the output, codify the behavior as a snapshot test by adding a new
-`test_case` macro in the relevant `src/[plugin-name]/mod.rs` file. Then, run `cargo test`. Your
-test will fail, but you'll be prompted to follow-up with `cargo insta review`. Accept the generated
-snapshot, then commit the snapshot file alongside the rest of your changes.
+`test_case` macro in the relevant `src/[plugin-name]/mod.rs` file. Then, run `cargo test --all`.
+Your test will fail, but you'll be prompted to follow-up with `cargo insta review`. Accept the
+generated snapshot, then commit the snapshot file alongside the rest of your changes.

 Finally, regenerate the documentation and generated code with `cargo +nightly dev generate-all`.

--- a/.github/ISSUE_TEMPLATE.md
+++ b/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,10 @@
+<!--
+Thank you for taking the time to report an issue! We're glad to have you involved with Ruff.
+
+If you're filing a bug report, please consider including the following information:
+
+- A minimal code snippet that reproduces the bug.
+- The command you invoked (e.g., `ruff /path/to/file.py --fix`), ideally including the `--isolated` flag.
+- The current Ruff settings (any relevant sections from your `pyproject.toml`).
+- The current Ruff version (`ruff --version`).
+-->
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -42,9 +42,8 @@ jobs:
      - run: cargo build --all --release
      - run: ./target/release/ruff_dev generate-all
      - run: git diff --quiet README.md || echo "::error file=README.md::This file is outdated. Run 'cargo +nightly dev generate-all'."
-      - run: git diff --quiet src/registry_gen.rs || echo "::error file=src/registry_gen.rs::This file is outdated. Run 'cargo +nightly dev generate-all'."
      - run: git diff --quiet ruff.schema.json || echo "::error file=ruff.schema.json::This file is outdated. Run 'cargo +nightly dev generate-all'."
-      - run: git diff --exit-code -- README.md src/registry_gen.rs ruff.schema.json
+      - run: git diff --exit-code -- README.md ruff.schema.json

  cargo-fmt:
    name: "cargo fmt"
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
  - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.211
+    rev: v0.0.216
    hooks:
      - id: ruff

--- a/Cargo.lock
+++ b/Cargo.lock
@@ -367,15 +367,6 @@ dependencies = [
 "winapi",
 ]

-[[package]]
-name = "codegen"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ff61280aed771c3070e7dcc9e050c66f1eb1e3b96431ba66f9f74641d02fc41d"
-dependencies = [
- "indexmap",
-]
-
 [[package]]
 name = "codespan-reporting"
 version = "0.11.1"
@@ -744,10 +735,11 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"

 [[package]]
 name = "flake8-to-ruff"
-version = "0.0.211-dev.0"
+version = "0.0.216-dev.0"
 dependencies = [
 "anyhow",
 "clap 4.0.32",
+ "colored",
 "configparser",
 "once_cell",
 "regex",
@@ -757,7 +749,7 @@ dependencies = [
 "serde_json",
 "strum",
 "strum_macros",
- "toml",
+ "toml_edit",
 ]

 [[package]]
@@ -1294,6 +1286,15 @@ dependencies = [
 "version_check",
 ]

+[[package]]
+name = "nom8"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae01545c9c7fc4486ab7debaf2aad7003ac19431791868fb2e8066df97fad2f8"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "notify"
 version = "5.0.0"
@@ -1365,9 +1366,9 @@ dependencies = [

 [[package]]
 name = "once_cell"
-version = "1.16.0"
+version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86f0b0d4bf799edbc74508c1e8bf170ff5f41238e5f8225603ca7caaae2b7860"
+checksum = "6f61fba1741ea2b3d6a1e3178721804bb716a68a6aeba1149b5d52e3d464ea66"

 [[package]]
 name = "oorandom"
@@ -1873,7 +1874,7 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.216"
 dependencies = [
 "annotate-snippets 0.9.1",
 "anyhow",
@@ -1931,7 +1932,7 @@ dependencies = [
 "test-case",
 "textwrap",
 "titlecase",
- "toml",
+ "toml_edit",
 "update-informer",
 "ureq",
 "walkdir",
@@ -1941,11 +1942,10 @@ dependencies = [

 [[package]]
 name = "ruff_dev"
-version = "0.0.211"
+version = "0.0.216"
 dependencies = [
 "anyhow",
 "clap 4.0.32",
- "codegen",
 "itertools",
 "libcst",
 "once_cell",
@@ -1962,8 +1962,9 @@ dependencies = [

 [[package]]
 name = "ruff_macros"
-version = "0.0.211"
+version = "0.0.216"
 dependencies = [
+ "once_cell",
 "proc-macro2",
 "quote",
 "syn",
@@ -2005,7 +2006,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+source = "git+https://github.com/RustPython/RustPython.git?rev=d532160333ffeb6dbeca2c2728c2391cd1e53b7f#d532160333ffeb6dbeca2c2728c2391cd1e53b7f"
 dependencies = [
 "num-bigint",
 "rustpython-common",
@@ -2015,7 +2016,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+source = "git+https://github.com/RustPython/RustPython.git?rev=d532160333ffeb6dbeca2c2728c2391cd1e53b7f#d532160333ffeb6dbeca2c2728c2391cd1e53b7f"
 dependencies = [
 "ascii",
 "bitflags",
@@ -2040,7 +2041,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+source = "git+https://github.com/RustPython/RustPython.git?rev=d532160333ffeb6dbeca2c2728c2391cd1e53b7f#d532160333ffeb6dbeca2c2728c2391cd1e53b7f"
 dependencies = [
 "bincode",
 "bitflags",
@@ -2057,7 +2058,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+source = "git+https://github.com/RustPython/RustPython.git?rev=d532160333ffeb6dbeca2c2728c2391cd1e53b7f#d532160333ffeb6dbeca2c2728c2391cd1e53b7f"
 dependencies = [
 "ahash",
 "anyhow",
@@ -2496,14 +2497,27 @@ dependencies = [
 ]

 [[package]]
-name = "toml"
-version = "0.5.10"
+name = "toml_datetime"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1333c76748e868a4d9d1017b5ab53171dfd095f70c712fdb4653a406547f598f"
+checksum = "808b51e57d0ef8f71115d8f3a01e7d3750d01c79cac4b3eda910f4389fdf92fd"
 dependencies = [
 "serde",
 ]

+[[package]]
+name = "toml_edit"
+version = "0.17.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a34cc558345efd7e88b9eda9626df2138b80bb46a7606f695e751c892bc7dac6"
+dependencies = [
+ "indexmap",
+ "itertools",
+ "nom8",
+ "serde",
+ "toml_datetime",
+]
+
 [[package]]
 name = "twox-hash"
 version = "1.6.3"
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,7 +6,7 @@ members = [

 [package]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.216"
 authors = ["Charlie Marsh <charlie.r.marsh@gmail.com>"]
 edition = "2021"
 rust-version = "1.65.0"
@@ -29,7 +29,7 @@ bitflags = { version = "1.3.2" }
 cachedir = { version = "0.3.0" }
 cfg-if = { version = "1.0.0" }
 chrono = { version = "0.4.21", default-features = false, features = ["clock"] }
-clap = { version = "4.0.1", features = ["derive"] }
+clap = { version = "4.0.1", features = ["derive", "env"] }
 clap_complete_command = { version = "0.4.0" }
 colored = { version = "2.0.0" }
 dirs = { version = "4.0.0" }
@@ -51,11 +51,11 @@ path-absolutize = { version = "3.0.14", features = ["once_cell_cache", "use_unix
 quick-junit = { version = "0.3.2" }
 regex = { version = "1.6.0" }
 ropey = { version = "1.5.0", features = ["cr_lines", "simd"], default-features = false }
-ruff_macros = { version = "0.0.211", path = "ruff_macros" }
+ruff_macros = { version = "0.0.216", path = "ruff_macros" }
 rustc-hash = { version = "1.1.0" }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "4d53c7cb27c0379adf8b51c4d3d0d2174f41d590" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "4d53c7cb27c0379adf8b51c4d3d0d2174f41d590" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "4d53c7cb27c0379adf8b51c4d3d0d2174f41d590" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "d532160333ffeb6dbeca2c2728c2391cd1e53b7f" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "d532160333ffeb6dbeca2c2728c2391cd1e53b7f" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "d532160333ffeb6dbeca2c2728c2391cd1e53b7f" }
 schemars = { version = "0.8.11" }
 semver = { version = "1.0.16" }
 serde = { version = "1.0.147", features = ["derive"] }
@@ -66,7 +66,7 @@ strum = { version = "0.24.1", features = ["strum_macros"] }
 strum_macros = { version = "0.24.3" }
 textwrap = { version = "0.16.0" }
 titlecase = { version = "2.2.1" }
-toml = { version = "0.5.9" }
+toml_edit = { version = "0.17.1", features = ["easy"] }
 walkdir = { version = "2.3.2" }

 [target.'cfg(not(target_family = "wasm"))'.dependencies]
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Ruff

-[![Ruff](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/charliermarsh/ruff/main/assets/badge/v0.json)](https://github.com/charliermarsh/ruff)
+[![Ruff](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/charliermarsh/ruff/main/assets/badge/v1.json)](https://github.com/charliermarsh/ruff)
 [![image](https://img.shields.io/pypi/v/ruff.svg)](https://pypi.python.org/pypi/ruff)
 [![image](https://img.shields.io/pypi/l/ruff.svg)](https://pypi.python.org/pypi/ruff)
 [![image](https://img.shields.io/pypi/pyversions/ruff.svg)](https://pypi.python.org/pypi/ruff)
@@ -180,7 +180,7 @@ Ruff also works with [pre-commit](https://pre-commit.com):
 ```yaml
 - repo: https://github.com/charliermarsh/ruff-pre-commit
  # Ruff version.
-  rev: 'v0.0.211'
+  rev: 'v0.0.216'
  hooks:
    - id: ruff
      # Respect `exclude` and `extend-exclude` settings.
@@ -312,7 +312,7 @@ ruff path/to/code/ --select F401 --select F403
 See `ruff --help` for more:

 <!-- Begin auto-generated cli help. -->
-```shell
+```
 Ruff: An extremely fast Python linter.

 Usage: ruff [OPTIONS] [FILES]...
@@ -341,8 +341,10 @@ Options:
          Avoid writing any fixed files back; instead, output a diff for each changed file to stdout
  -n, --no-cache
          Disable cache reads
+      --isolated
+          Ignore all configuration files
      --select <SELECT>
-          Comma-separated list of error codes to enable (or ALL, to enable all checks)
+          Comma-separated list of rule codes to enable (or ALL, to enable all rules)
      --extend-select <EXTEND_SELECT>
          Like --select, but adds additional error codes on top of the selected ones
      --ignore <IGNORE>
@@ -360,11 +362,11 @@ Options:
      --per-file-ignores <PER_FILE_IGNORES>
          List of mappings from file pattern to code to exclude
      --format <FORMAT>
-          Output serialization format for error messages [possible values: text, json, junit, grouped, github, gitlab]
+          Output serialization format for error messages [env: RUFF_FORMAT=] [possible values: text, json, junit, grouped, github, gitlab]
      --stdin-filename <STDIN_FILENAME>
          The name of the file when passing it through stdin
      --cache-dir <CACHE_DIR>
-          Path to the cache directory
+          Path to the cache directory [env: RUFF_CACHE_DIR=]
      --show-source
          Show violations with source code
      --respect-gitignore
@@ -551,8 +553,8 @@ For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
 | F524 | StringDotFormatMissingArguments | '...'.format(...) is missing argument(s) for placeholder(s): ... |  |
 | F525 | StringDotFormatMixingAutomatic | '...'.format(...) mixes automatic and manual numbering |  |
 | F541 | FStringMissingPlaceholders | f-string without any placeholders | 🛠 |
-| F601 | MultiValueRepeatedKeyLiteral | Dictionary key literal repeated |  |
-| F602 | MultiValueRepeatedKeyVariable | Dictionary key `...` repeated |  |
+| F601 | MultiValueRepeatedKeyLiteral | Dictionary key literal `...` repeated | 🛠 |
+| F602 | MultiValueRepeatedKeyVariable | Dictionary key `...` repeated | 🛠 |
 | F621 | ExpressionsInStarAssignment | Too many expressions in star-unpacking assignment |  |
 | F622 | TwoStarredExpressions | Two starred expressions in assignment |  |
 | F631 | AssertTuple | Assert test is a non-empty tuple, which is always `True` |  |
@@ -569,7 +571,7 @@ For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
 | F821 | UndefinedName | Undefined name `...` |  |
 | F822 | UndefinedExport | Undefined name `...` in `__all__` |  |
 | F823 | UndefinedLocal | Local variable `...` referenced before assignment |  |
-| F841 | UnusedVariable | Local variable `...` is assigned to but never used |  |
+| F841 | UnusedVariable | Local variable `...` is assigned to but never used | 🛠 |
 | F842 | UnusedAnnotation | Local variable `...` is annotated but never used |  |
 | F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` | 🛠 |

@@ -632,7 +634,7 @@ For more, see [pydocstyle](https://pypi.org/project/pydocstyle/6.1.1/) on PyPI.
 | D202 | NoBlankLineAfterFunction | No blank lines allowed after function docstring (found 1) | 🛠 |
 | D203 | OneBlankLineBeforeClass | 1 blank line required before class docstring | 🛠 |
 | D204 | OneBlankLineAfterClass | 1 blank line required after class docstring | 🛠 |
-| D205 | BlankLineAfterSummary | 1 blank line required between summary line and description | 🛠 |
+| D205 | BlankLineAfterSummary | 1 blank line required between summary line and description (found 2) | 🛠 |
 | D206 | IndentWithSpaces | Docstring should be indented with spaces, not tabs |  |
 | D207 | NoUnderIndentation | Docstring is under-indented | 🛠 |
 | D208 | NoOverIndentation | Docstring is over-indented | 🛠 |
@@ -767,10 +769,14 @@ For more, see [flake8-bandit](https://pypi.org/project/flake8-bandit/4.1.1/) on
 | S102 | ExecUsed | Use of `exec` detected |  |
 | S103 | BadFilePermissions | `os.chmod` setting a permissive mask `0o777` on file or directory |  |
 | S104 | HardcodedBindAllInterfaces | Possible binding to all interfaces |  |
-| S105 | HardcodedPasswordString | Possible hardcoded password: `"..."` |  |
-| S106 | HardcodedPasswordFuncArg | Possible hardcoded password: `"..."` |  |
-| S107 | HardcodedPasswordDefault | Possible hardcoded password: `"..."` |  |
-| S108 | HardcodedTempFile | Probable insecure usage of temp file/directory: `"..."` |  |
+| S105 | HardcodedPasswordString | Possible hardcoded password: "..." |  |
+| S106 | HardcodedPasswordFuncArg | Possible hardcoded password: "..." |  |
+| S107 | HardcodedPasswordDefault | Possible hardcoded password: "..." |  |
+| S108 | HardcodedTempFile | Probable insecure usage of temporary file or directory: "..." |  |
+| S113 | RequestWithoutTimeout | Probable use of requests call without timeout |  |
+| S324 | HashlibInsecureHashFunction | Probable use of insecure hash functions in `hashlib`: "..." |  |
+| S501 | RequestWithNoCertValidation | Probable use of `...` call with `verify=False` disabling SSL certificate checks |  |
+| S506 | UnsafeYAMLLoad | Probable use of unsafe `yaml.load`. Allows instantiation of arbitrary objects. Consider `yaml.safe_load`. |  |

 ### flake8-blind-except (BLE)

@@ -910,27 +916,27 @@ For more, see [flake8-pytest-style](https://pypi.org/project/flake8-pytest-style
 | PT001 | IncorrectFixtureParenthesesStyle | Use `@pytest.fixture()` over `@pytest.fixture` | 🛠 |
 | PT002 | FixturePositionalArgs | Configuration for fixture `...` specified via positional args, use kwargs |  |
 | PT003 | ExtraneousScopeFunction | `scope='function'` is implied in `@pytest.fixture()` |  |
-| PT004 | MissingFixtureNameUnderscore | Fixture `...` does not return anything, add leading underscore |  |
-| PT005 | IncorrectFixtureNameUnderscore | Fixture `...` returns a value, remove leading underscore |  |
+| PT004 | MissingFixtureNameUnderscore | Fixture `...` does not return anything, add leading underscore | 🛠 |
+| PT005 | IncorrectFixtureNameUnderscore | Fixture `...` returns a value, remove leading underscore | 🛠 |
 | PT006 | ParametrizeNamesWrongType | Wrong name(s) type in `@pytest.mark.parametrize`, expected `tuple` | 🛠 |
 | PT007 | ParametrizeValuesWrongType | Wrong values type in `@pytest.mark.parametrize` expected `list` of `tuple` |  |
-| PT008 | PatchWithLambda | Use `return_value=` instead of patching with lambda |  |
-| PT009 | UnittestAssertion | Use a regular assert instead of unittest-style '...' |  |
+| PT008 | PatchWithLambda | Use `return_value=` instead of patching with `lambda` |  |
+| PT009 | UnittestAssertion | Use a regular `assert` instead of unittest-style `...` | 🛠 |
 | PT010 | RaisesWithoutException | set the expected exception in `pytest.raises()` |  |
 | PT011 | RaisesTooBroad | `pytest.raises(...)` is too broad, set the `match` parameter or use a more specific exception |  |
 | PT012 | RaisesWithMultipleStatements | `pytest.raises()` block should contain a single simple statement |  |
 | PT013 | IncorrectPytestImport | Found incorrect import of pytest, use simple `import pytest` instead |  |
 | PT015 | AssertAlwaysFalse | Assertion always fails, replace with `pytest.fail()` |  |
 | PT016 | FailWithoutMessage | No message passed to `pytest.fail()` |  |
-| PT017 | AssertInExcept | Found assertion on exception ... in except block, use pytest.raises() instead |  |
+| PT017 | AssertInExcept | Found assertion on exception `...` in except block, use `pytest.raises()` instead |  |
 | PT018 | CompositeAssertion | Assertion should be broken down into multiple parts |  |
-| PT019 | FixtureParamWithoutValue | Fixture ... without value is injected as parameter, use @pytest.mark.usefixtures instead |  |
+| PT019 | FixtureParamWithoutValue | Fixture `...` without value is injected as parameter, use `@pytest.mark.usefixtures` instead |  |
 | PT020 | DeprecatedYieldFixture | `@pytest.yield_fixture` is deprecated, use `@pytest.fixture` |  |
 | PT021 | FixtureFinalizerCallback | Use `yield` instead of `request.addfinalizer` |  |
-| PT022 | UselessYieldFixture | No teardown in fixture ..., use `return` instead of `yield` | 🛠 |
+| PT022 | UselessYieldFixture | No teardown in fixture `...`, use `return` instead of `yield` | 🛠 |
 | PT023 | IncorrectMarkParenthesesStyle | Use `@pytest.mark....` over `@pytest.mark....()` | 🛠 |
-| PT024 | UnnecessaryAsyncioMarkOnFixture | `pytest.mark.asyncio` is unnecessary for fixtures |  |
-| PT025 | ErroneousUseFixturesOnFixture | `pytest.mark.usefixtures` has no effect on fixtures |  |
+| PT024 | UnnecessaryAsyncioMarkOnFixture | `pytest.mark.asyncio` is unnecessary for fixtures | 🛠 |
+| PT025 | ErroneousUseFixturesOnFixture | `pytest.mark.usefixtures` has no effect on fixtures | 🛠 |
 | PT026 | UseFixturesWithoutParameters | Useless `pytest.mark.usefixtures` without parameters | 🛠 |

 ### flake8-quotes (Q)
@@ -965,13 +971,23 @@ For more, see [flake8-simplify](https://pypi.org/project/flake8-simplify/0.19.3/

 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
+| SIM101 | DuplicateIsinstanceCall | Multiple `isinstance` calls for `...`, merge into a single call | 🛠 |
 | SIM102 | NestedIfStatements | Use a single `if` statement instead of nested `if` statements |  |
+| SIM103 | ReturnBoolConditionDirectly | Return the condition `...` directly | 🛠 |
 | SIM105 | UseContextlibSuppress | Use `contextlib.suppress(...)` instead of try-except-pass |  |
 | SIM107 | ReturnInTryExceptFinally | Don't use `return` in `try`/`except` and `finally` |  |
+| SIM108 | UseTernaryOperator | Use ternary operator `...` instead of if-else-block | 🛠 |
+| SIM109 | CompareWithTuple | Use `value in (..., ...)` instead of `value == ... or value == ...` | 🛠 |
 | SIM110 | ConvertLoopToAny | Use `return any(x for x in y)` instead of `for` loop | 🛠 |
 | SIM111 | ConvertLoopToAll | Use `return all(x for x in y)` instead of `for` loop | 🛠 |
 | SIM117 | MultipleWithStatements | Use a single `with` statement with multiple contexts instead of nested `with` statements |  |
 | SIM118 | KeyInDict | Use `key in dict` instead of `key in dict.keys()` | 🛠 |
+| SIM201 | NegateEqualOp | Use `left != right` instead of `not left == right` | 🛠 |
+| SIM202 | NegateNotEqualOp | Use `left == right` instead of `not left != right` | 🛠 |
+| SIM208 | DoubleNegation | Use `expr` instead of `not (not expr)` | 🛠 |
+| SIM210 | IfExprWithTrueFalse | Use `bool(expr)` instead of `True if expr else False` | 🛠 |
+| SIM211 | IfExprWithFalseTrue | Use `not expr` instead of `False if expr else True` | 🛠 |
+| SIM212 | IfExprWithTwistedArms | Use `b if b else a` instead of `a if not b else b` | 🛠 |
 | SIM220 | AAndNotA | Use `False` instead of `... and not ...` | 🛠 |
 | SIM221 | AOrNotA | Use `True` instead of `... or not ...` | 🛠 |
 | SIM222 | OrTrue | Use `True` instead of `... or True` | 🛠 |
@@ -1317,8 +1333,9 @@ jobs:
        run: |
          python -m pip install --upgrade pip
          pip install ruff
+      # Include `--format=github` to enable automatic inline annotations.
      - name: Run Ruff
-        run: ruff .
+        run: ruff --format=github .
 ```

 ## FAQ
@@ -1722,6 +1739,24 @@ allowed-confusables = ["−", "ρ", "∗"]

 ---

+#### [`builtins`](#builtins)
+
+A list of builtins to treat as defined references, in addition to the
+system builtins.
+
+**Default value**: `[]`
+
+**Type**: `Vec<String>`
+
+**Example usage**:
+
+```toml
+[tool.ruff]
+builtins = ["_"]
+```
+
+---
+
 #### [`cache-dir`](#cache-dir)

 A path to the cache directory.
@@ -1850,7 +1885,7 @@ by `ignore`.

 **Default value**: `[]`

-**Type**: `Vec<CheckCodePrefix>`
+**Type**: `Vec<RuleCodePrefix>`

 **Example usage**:

@@ -1869,7 +1904,7 @@ by `select`.

 **Default value**: `[]`

-**Type**: `Vec<CheckCodePrefix>`
+**Type**: `Vec<RuleCodePrefix>`

 **Example usage**:

@@ -1886,7 +1921,7 @@ extend-select = ["B", "Q"]
 A list of check codes that are unsupported by Ruff, but should be
 preserved when (e.g.) validating `# noqa` directives. Useful for
 retaining `# noqa` directives that cover plugins not yet implemented
-in Ruff.
+by Ruff.

 **Default value**: `[]`

@@ -1944,7 +1979,7 @@ A list of check code prefixes to consider autofix-able.

 **Default value**: `["A", "ANN", "ARG", "B", "BLE", "C", "D", "E", "ERA", "F", "FBT", "I", "ICN", "N", "PGH", "PLC", "PLE", "PLR", "PLW", "Q", "RET", "RUF", "S", "T", "TID", "UP", "W", "YTT"]`

-**Type**: `Vec<CheckCodePrefix>`
+**Type**: `Vec<RuleCodePrefix>`

 **Example usage**:

@@ -2016,7 +2051,7 @@ specific prefixes.

 **Default value**: `[]`

-**Type**: `Vec<CheckCodePrefix>`
+**Type**: `Vec<RuleCodePrefix>`

 **Example usage**:

@@ -2075,7 +2110,7 @@ when considering any matching files.

 **Default value**: `{}`

-**Type**: `HashMap<String, Vec<CheckCodePrefix>>`
+**Type**: `HashMap<String, Vec<RuleCodePrefix>>`

 **Example usage**:

@@ -2139,7 +2174,7 @@ specific prefixes.

 **Default value**: `["E", "F"]`

-**Type**: `Vec<CheckCodePrefix>`
+**Type**: `Vec<RuleCodePrefix>`

 **Example usage**:

@@ -2259,7 +2294,7 @@ A list of check code prefixes to consider un-autofix-able.

 **Default value**: `[]`

-**Type**: `Vec<CheckCodePrefix>`
+**Type**: `Vec<RuleCodePrefix>`

 **Example usage**:

@@ -2459,9 +2494,10 @@ the `extend_aliases` option.

 ```toml
 [tool.ruff.flake8-import-conventions]
+[tool.ruff.flake8-import-conventions.aliases]
 # Declare the default aliases.
 altair = "alt"
-matplotlib.pyplot = "plt"
+"matplotlib.pyplot" = "plt"
 numpy = "np"
 pandas = "pd"
 seaborn = "sns"
@@ -2482,6 +2518,7 @@ will be added to the `aliases` mapping.

 ```toml
 [tool.ruff.flake8-import-conventions]
+[tool.ruff.flake8-import-conventions.extend-aliases]
 # Declare a custom alias for the `matplotlib` module.
 "dask.dataframe" = "dd"
 ```
@@ -2831,6 +2868,25 @@ force-single-line = true

 ---

+#### [`force-sort-within-sections`](#force-sort-within-sections)
+
+Don't sort straight-style imports (like `import sys`) before from-style
+imports (like `from itertools import groupby`). Instead, sort the
+imports by module, independent of import style.
+
+**Default value**: `false`
+
+**Type**: `bool`
+
+**Example usage**:
+
+```toml
+[tool.ruff.isort]
+force-sort-within-sections = true
+```
+
+---
+
 #### [`force-wrap-aliases`](#force-wrap-aliases)

 Force `import from` statements with multiple members and at least one
@@ -3111,4 +3167,4 @@ MIT
 ## Contributing

 Contributions are welcome and hugely appreciated. To get started, check out the
-[contributing guidelines](https://github.com/charliermarsh/ruff/blob/main/CONTRIBUTING.md).
+[contributing guidelines](https://github.com/charliermarsh/ruff/blob/main/.github/CONTRIBUTING.md).
--- a/assets/badge/v0.json
+++ b/assets/badge/v0.json
@@ -1,8 +1,8 @@
 {
-    "label": "",
-    "message": "Ruff",
-    "logoSvg": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"128\" height=\"128\"><path d=\"M115.36 61.84 70.22 50.49 114.45 2.4a1.222 1.222 0 0 0-1.54-1.87L12.3 61.98c-.41.25-.64.72-.57 1.2.06.48.4.87.87 1.01l45.07 13.25-44.29 48.16c-.42.46-.44 1.15-.04 1.61.24.29.58.44.94.44.22 0 .45-.06.65-.19l100.78-63.41c.42-.26.64-.75.56-1.22-.08-.49-.43-.88-.91-.99z\" style=\"fill:#fcc21b\"/></svg>",
-    "logoWidth": 10,
-    "labelColor": "grey",
-    "color": "#E15759"
+  "label": "",
+  "message": "Ruff",
+  "logoSvg": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"128\" height=\"128\"><path d=\"M115.36 61.84 70.22 50.49 114.45 2.4a1.222 1.222 0 0 0-1.54-1.87L12.3 61.98c-.41.25-.64.72-.57 1.2.06.48.4.87.87 1.01l45.07 13.25-44.29 48.16c-.42.46-.44 1.15-.04 1.61.24.29.58.44.94.44.22 0 .45-.06.65-.19l100.78-63.41c.42-.26.64-.75.56-1.22-.08-.49-.43-.88-.91-.99z\" style=\"fill:#fcc21b\"/></svg>",
+  "logoWidth": 10,
+  "labelColor": "grey",
+  "color": "#E15759"
 }
--- a/assets/badge/v1.json
+++ b/assets/badge/v1.json
@@ -0,0 +1,8 @@
+{
+  "label": "",
+  "message": "Ruff",
+  "logoSvg": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"109\" height=\"132\" fill=\"none\"><g filter=\"url(#a)\"><path fill=\"#FCC21B\" d=\"m103.642 61.492-45.14-11.35 44.23-48.09a1.222 1.222 0 0 0-1.54-1.87L.582 61.632c-.41.25-.64.72-.57 1.2.06.48.4.87.87 1.01l45.07 13.25-44.29 48.16c-.42.46-.44 1.15-.04 1.61.24.29.58.44.94.44.22 0 .45-.06.65-.19l100.78-63.41c.42-.26.64-.75.56-1.22-.08-.49-.43-.88-.91-.99Z\"/></g><defs><filter id=\"a\" width=\"108.569\" height=\"131.302\" x=\"0\" y=\"0\" color-interpolation-filters=\"sRGB\" filterUnits=\"userSpaceOnUse\"><feFlood flood-opacity=\"0\" result=\"BackgroundImageFix\"/><feColorMatrix in=\"SourceAlpha\" result=\"hardAlpha\" values=\"0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 0\"/><feOffset dx=\"4\" dy=\"4\"/><feComposite in2=\"hardAlpha\" operator=\"out\"/><feColorMatrix values=\"0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0\"/><feBlend in2=\"BackgroundImageFix\" result=\"effect1_dropShadow_7_4\"/><feBlend in=\"SourceGraphic\" in2=\"effect1_dropShadow_7_4\" result=\"shape\"/></filter></defs></svg>",
+  "logoWidth": 10,
+  "labelColor": "grey",
+  "color": "#E15759"
+}
--- a/flake8_to_ruff/Cargo.lock
+++ b/flake8_to_ruff/Cargo.lock
@@ -771,7 +771,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"

 [[package]]
 name = "flake8_to_ruff"
-version = "0.0.211"
+version = "0.0.216"
 dependencies = [
 "anyhow",
 "clap",
@@ -1975,7 +1975,7 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.216"
 dependencies = [
 "anyhow",
 "bincode",
--- a/flake8_to_ruff/Cargo.toml
+++ b/flake8_to_ruff/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "flake8-to-ruff"
-version = "0.0.211-dev.0"
+version = "0.0.216-dev.0"
 edition = "2021"

 [lib]
@@ -9,6 +9,7 @@ name = "flake8_to_ruff"
 [dependencies]
 anyhow = { version = "1.0.66" }
 clap = { version = "4.0.1", features = ["derive"] }
+colored = { version = "2.0.0" }
 configparser = { version = "3.0.2" }
 once_cell = { version = "1.16.0" }
 regex = { version = "1.6.0" }
@@ -18,7 +19,7 @@ serde = { version = "1.0.147", features = ["derive"] }
 serde_json = { version = "1.0.87" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
 strum_macros = { version = "0.24.3" }
-toml = { version = "0.5.9" }
+toml_edit = { version = "0.17.1", features = ["easy"] }

 [dev-dependencies]

--- a/flake8_to_ruff/examples/jupyterhub.ini
+++ b/flake8_to_ruff/examples/jupyterhub.ini
@@ -0,0 +1,19 @@
+[flake8]
+# Ignore style and complexity
+# E: style errors
+# W: style warnings
+# C: complexity
+# D: docstring warnings (unused pydocstyle extension)
+# F841: local variable assigned but never used
+ignore = E, C, W, D, F841
+builtins = c, get_config
+exclude =
+    .cache,
+    .github,
+    docs,
+    jupyterhub/alembic*,
+    onbuild,
+    scripts,
+    share,
+    tools,
+    setup.py
--- a/flake8_to_ruff/src/black.rs
+++ b/flake8_to_ruff/src/black.rs
@@ -26,7 +26,7 @@ struct Pyproject {

 pub fn parse_black_options<P: AsRef<Path>>(path: P) -> Result<Option<Black>> {
    let contents = std::fs::read_to_string(path)?;
-    Ok(toml::from_str::<Pyproject>(&contents)?
+    Ok(toml_edit::easy::from_str::<Pyproject>(&contents)?
        .tool
        .and_then(|tool| tool.black))
 }
--- a/flake8_to_ruff/src/converter.rs
+++ b/flake8_to_ruff/src/converter.rs
@@ -1,18 +1,19 @@
 use std::collections::{BTreeSet, HashMap};

 use anyhow::Result;
+use colored::Colorize;
 use ruff::flake8_pytest_style::types::{
    ParametrizeNameType, ParametrizeValuesRowType, ParametrizeValuesType,
 };
 use ruff::flake8_quotes::settings::Quote;
 use ruff::flake8_tidy_imports::settings::Strictness;
 use ruff::pydocstyle::settings::Convention;
-use ruff::registry_gen::CheckCodePrefix;
+use ruff::registry::RuleCodePrefix;
 use ruff::settings::options::Options;
 use ruff::settings::pyproject::Pyproject;
 use ruff::{
    flake8_annotations, flake8_bugbear, flake8_errmsg, flake8_pytest_style, flake8_quotes,
-    flake8_tidy_imports, mccabe, pep8_naming, pydocstyle,
+    flake8_tidy_imports, mccabe, pep8_naming, pydocstyle, warn_user,
 };

 use crate::black::Black;
@@ -30,7 +31,7 @@ pub fn convert(
        .expect("Unable to find flake8 section in INI file");

    // Extract all referenced check code prefixes, to power plugin inference.
-    let mut referenced_codes: BTreeSet<CheckCodePrefix> = BTreeSet::default();
+    let mut referenced_codes: BTreeSet<RuleCodePrefix> = BTreeSet::default();
    for (key, value) in flake8 {
        if let Some(value) = value {
            match key.as_str() {
@@ -60,7 +61,7 @@ pub fn convert(
        }
        let from_codes = plugin::infer_plugins_from_codes(&referenced_codes);
        if !from_codes.is_empty() {
-            eprintln!("Inferred plugins from referenced check codes: {from_codes:#?}");
+            eprintln!("Inferred plugins from referenced codes: {from_codes:#?}");
        }
        from_options.into_iter().chain(from_codes).collect()
    });
@@ -99,9 +100,14 @@ pub fn convert(
        if let Some(value) = value {
            match key.as_str() {
                // flake8
+                "builtins" => {
+                    options.builtins = Some(parser::parse_strings(value.as_ref()));
+                }
                "max-line-length" | "max_line_length" => match value.clone().parse::<usize>() {
                    Ok(line_length) => options.line_length = Some(line_length),
-                    Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    Err(e) => {
+                        warn_user!("Unable to parse '{key}' property: {e}");
+                    }
                },
                "select" => {
                    // No-op (handled above).
@@ -130,7 +136,9 @@ pub fn convert(
                            options.per_file_ignores =
                                Some(parser::collect_per_file_ignores(per_file_ignores));
                        }
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                // flake8-bugbear
@@ -142,46 +150,62 @@ pub fn convert(
                "suppress-none-returning" | "suppress_none_returning" => {
                    match parser::parse_bool(value.as_ref()) {
                        Ok(bool) => flake8_annotations.suppress_none_returning = Some(bool),
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                "suppress-dummy-args" | "suppress_dummy_args" => {
                    match parser::parse_bool(value.as_ref()) {
                        Ok(bool) => flake8_annotations.suppress_dummy_args = Some(bool),
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                "mypy-init-return" | "mypy_init_return" => {
                    match parser::parse_bool(value.as_ref()) {
                        Ok(bool) => flake8_annotations.mypy_init_return = Some(bool),
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                "allow-star-arg-any" | "allow_star_arg_any" => {
                    match parser::parse_bool(value.as_ref()) {
                        Ok(bool) => flake8_annotations.allow_star_arg_any = Some(bool),
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                // flake8-quotes
                "quotes" | "inline-quotes" | "inline_quotes" => match value.trim() {
                    "'" | "single" => flake8_quotes.inline_quotes = Some(Quote::Single),
                    "\"" | "double" => flake8_quotes.inline_quotes = Some(Quote::Double),
-                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                    _ => {
+                        warn_user!("Unexpected '{key}' value: {value}");
+                    }
                },
                "multiline-quotes" | "multiline_quotes" => match value.trim() {
                    "'" | "single" => flake8_quotes.multiline_quotes = Some(Quote::Single),
                    "\"" | "double" => flake8_quotes.multiline_quotes = Some(Quote::Double),
-                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                    _ => {
+                        warn_user!("Unexpected '{key}' value: {value}");
+                    }
                },
                "docstring-quotes" | "docstring_quotes" => match value.trim() {
                    "'" | "single" => flake8_quotes.docstring_quotes = Some(Quote::Single),
                    "\"" | "double" => flake8_quotes.docstring_quotes = Some(Quote::Double),
-                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                    _ => {
+                        warn_user!("Unexpected '{key}' value: {value}");
+                    }
                },
                "avoid-escape" | "avoid_escape" => match parser::parse_bool(value.as_ref()) {
                    Ok(bool) => flake8_quotes.avoid_escape = Some(bool),
-                    Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    Err(e) => {
+                        warn_user!("Unable to parse '{key}' property: {e}");
+                    }
                },
                // pep8-naming
                "ignore-names" | "ignore_names" => {
@@ -201,7 +225,9 @@ pub fn convert(
                    "parents" => {
                        flake8_tidy_imports.ban_relative_imports = Some(Strictness::Parents);
                    }
-                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                    _ => {
+                        warn_user!("Unexpected '{key}' value: {value}");
+                    }
                },
                // flake8-docstrings
                "docstring-convention" => match value.trim() {
@@ -209,12 +235,16 @@ pub fn convert(
                    "numpy" => pydocstyle.convention = Some(Convention::Numpy),
                    "pep257" => pydocstyle.convention = Some(Convention::Pep257),
                    "all" => pydocstyle.convention = None,
-                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                    _ => {
+                        warn_user!("Unexpected '{key}' value: {value}");
+                    }
                },
                // mccabe
                "max-complexity" | "max_complexity" => match value.clone().parse::<usize>() {
                    Ok(max_complexity) => mccabe.max_complexity = Some(max_complexity),
-                    Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    Err(e) => {
+                        warn_user!("Unable to parse '{key}' property: {e}");
+                    }
                },
                // flake8-errmsg
                "errmsg-max-string-length" | "errmsg_max_string_length" => {
@@ -222,14 +252,18 @@ pub fn convert(
                        Ok(max_string_length) => {
                            flake8_errmsg.max_string_length = Some(max_string_length);
                        }
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                // flake8-pytest-style
                "pytest-fixture-no-parentheses" | "pytest_fixture_no_parentheses " => {
                    match parser::parse_bool(value.as_ref()) {
                        Ok(bool) => flake8_pytest_style.fixture_parentheses = Some(!bool),
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                "pytest-parametrize-names-type" | "pytest_parametrize_names_type" => {
@@ -246,7 +280,9 @@ pub fn convert(
                            flake8_pytest_style.parametrize_names_type =
                                Some(ParametrizeNameType::List);
                        }
-                        _ => eprintln!("Unexpected '{key}' value: {value}"),
+                        _ => {
+                            warn_user!("Unexpected '{key}' value: {value}");
+                        }
                    }
                }
                "pytest-parametrize-values-type" | "pytest_parametrize_values_type" => {
@@ -259,7 +295,9 @@ pub fn convert(
                            flake8_pytest_style.parametrize_values_type =
                                Some(ParametrizeValuesType::List);
                        }
-                        _ => eprintln!("Unexpected '{key}' value: {value}"),
+                        _ => {
+                            warn_user!("Unexpected '{key}' value: {value}");
+                        }
                    }
                }
                "pytest-parametrize-values-row-type" | "pytest_parametrize_values_row_type" => {
@@ -272,7 +310,9 @@ pub fn convert(
                            flake8_pytest_style.parametrize_values_row_type =
                                Some(ParametrizeValuesRowType::List);
                        }
-                        _ => eprintln!("Unexpected '{key}' value: {value}"),
+                        _ => {
+                            warn_user!("Unexpected '{key}' value: {value}");
+                        }
                    }
                }
                "pytest-raises-require-match-for" | "pytest_raises_require_match_for" => {
@@ -282,11 +322,15 @@ pub fn convert(
                "pytest-mark-no-parentheses" | "pytest_mark_no_parentheses" => {
                    match parser::parse_bool(value.as_ref()) {
                        Ok(bool) => flake8_pytest_style.mark_parentheses = Some(!bool),
-                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                        Err(e) => {
+                            warn_user!("Unable to parse '{key}' property: {e}");
+                        }
                    }
                }
                // Unknown
-                _ => eprintln!("Skipping unsupported property: {key}"),
+                _ => {
+                    warn_user!("Skipping unsupported property: {}", key);
+                }
            }
        }
    }
@@ -345,7 +389,7 @@ mod tests {

    use anyhow::Result;
    use ruff::pydocstyle::settings::Convention;
-    use ruff::registry_gen::CheckCodePrefix;
+    use ruff::registry::RuleCodePrefix;
    use ruff::settings::options::Options;
    use ruff::settings::pyproject::Pyproject;
    use ruff::{flake8_quotes, pydocstyle};
@@ -362,6 +406,7 @@ mod tests {
        )?;
        let expected = Pyproject::new(Options {
            allowed_confusables: None,
+            builtins: None,
            cache_dir: None,
            dummy_variable_rgx: None,
            exclude: None,
@@ -382,9 +427,9 @@ mod tests {
            required_version: None,
            respect_gitignore: None,
            select: Some(vec![
-                CheckCodePrefix::E,
-                CheckCodePrefix::F,
-                CheckCodePrefix::W,
+                RuleCodePrefix::E,
+                RuleCodePrefix::F,
+                RuleCodePrefix::W,
            ]),
            show_source: None,
            src: None,
@@ -425,6 +470,7 @@ mod tests {
        )?;
        let expected = Pyproject::new(Options {
            allowed_confusables: None,
+            builtins: None,
            cache_dir: None,
            dummy_variable_rgx: None,
            exclude: None,
@@ -445,9 +491,9 @@ mod tests {
            required_version: None,
            respect_gitignore: None,
            select: Some(vec![
-                CheckCodePrefix::E,
-                CheckCodePrefix::F,
-                CheckCodePrefix::W,
+                RuleCodePrefix::E,
+                RuleCodePrefix::F,
+                RuleCodePrefix::W,
            ]),
            show_source: None,
            src: None,
@@ -488,6 +534,7 @@ mod tests {
        )?;
        let expected = Pyproject::new(Options {
            allowed_confusables: None,
+            builtins: None,
            cache_dir: None,
            dummy_variable_rgx: None,
            exclude: None,
@@ -508,9 +555,9 @@ mod tests {
            required_version: None,
            respect_gitignore: None,
            select: Some(vec![
-                CheckCodePrefix::E,
-                CheckCodePrefix::F,
-                CheckCodePrefix::W,
+                RuleCodePrefix::E,
+                RuleCodePrefix::F,
+                RuleCodePrefix::W,
            ]),
            show_source: None,
            src: None,
@@ -551,6 +598,7 @@ mod tests {
        )?;
        let expected = Pyproject::new(Options {
            allowed_confusables: None,
+            builtins: None,
            cache_dir: None,
            dummy_variable_rgx: None,
            exclude: None,
@@ -571,9 +619,9 @@ mod tests {
            required_version: None,
            respect_gitignore: None,
            select: Some(vec![
-                CheckCodePrefix::E,
-                CheckCodePrefix::F,
-                CheckCodePrefix::W,
+                RuleCodePrefix::E,
+                RuleCodePrefix::F,
+                RuleCodePrefix::W,
            ]),
            show_source: None,
            src: None,
@@ -614,6 +662,7 @@ mod tests {
        )?;
        let expected = Pyproject::new(Options {
            allowed_confusables: None,
+            builtins: None,
            cache_dir: None,
            dummy_variable_rgx: None,
            exclude: None,
@@ -634,9 +683,9 @@ mod tests {
            required_version: None,
            respect_gitignore: None,
            select: Some(vec![
-                CheckCodePrefix::E,
-                CheckCodePrefix::F,
-                CheckCodePrefix::W,
+                RuleCodePrefix::E,
+                RuleCodePrefix::F,
+                RuleCodePrefix::W,
            ]),
            show_source: None,
            src: None,
@@ -685,6 +734,7 @@ mod tests {
        )?;
        let expected = Pyproject::new(Options {
            allowed_confusables: None,
+            builtins: None,
            cache_dir: None,
            dummy_variable_rgx: None,
            exclude: None,
@@ -705,10 +755,10 @@ mod tests {
            required_version: None,
            respect_gitignore: None,
            select: Some(vec![
-                CheckCodePrefix::D,
-                CheckCodePrefix::E,
-                CheckCodePrefix::F,
-                CheckCodePrefix::W,
+                RuleCodePrefix::D,
+                RuleCodePrefix::E,
+                RuleCodePrefix::F,
+                RuleCodePrefix::W,
            ]),
            show_source: None,
            src: None,
@@ -751,6 +801,7 @@ mod tests {
        )?;
        let expected = Pyproject::new(Options {
            allowed_confusables: None,
+            builtins: None,
            cache_dir: None,
            dummy_variable_rgx: None,
            exclude: None,
@@ -771,10 +822,10 @@ mod tests {
            required_version: None,
            respect_gitignore: None,
            select: Some(vec![
-                CheckCodePrefix::E,
-                CheckCodePrefix::F,
-                CheckCodePrefix::Q,
-                CheckCodePrefix::W,
+                RuleCodePrefix::E,
+                RuleCodePrefix::F,
+                RuleCodePrefix::Q,
+                RuleCodePrefix::W,
            ]),
            show_source: None,
            src: None,
--- a/flake8_to_ruff/src/lib.rs
+++ b/flake8_to_ruff/src/lib.rs
@@ -10,6 +10,7 @@
    clippy::similar_names,
    clippy::too_many_lines
 )]
+#![forbid(unsafe_code)]

 pub mod black;
 pub mod converter;
--- a/flake8_to_ruff/src/main.rs
+++ b/flake8_to_ruff/src/main.rs
@@ -11,6 +11,7 @@
    clippy::similar_names,
    clippy::too_many_lines
 )]
+#![forbid(unsafe_code)]

 use std::path::PathBuf;

@@ -57,7 +58,7 @@ fn main() -> Result<()> {

    // Create Ruff's pyproject.toml section.
    let pyproject = converter::convert(&config, black.as_ref(), cli.plugin)?;
-    println!("{}", toml::to_string_pretty(&pyproject)?);
+    println!("{}", toml_edit::easy::to_string_pretty(&pyproject)?);

    Ok(())
 }
--- a/flake8_to_ruff/src/parser.rs
+++ b/flake8_to_ruff/src/parser.rs
@@ -1,19 +1,20 @@
 use std::str::FromStr;

 use anyhow::{bail, Result};
+use colored::Colorize;
 use once_cell::sync::Lazy;
 use regex::Regex;
-use ruff::registry::PREFIX_REDIRECTS;
-use ruff::registry_gen::CheckCodePrefix;
+use ruff::registry::{RuleCodePrefix, PREFIX_REDIRECTS};
 use ruff::settings::types::PatternPrefixPair;
+use ruff::warn_user;
 use rustc_hash::FxHashMap;

 static COMMA_SEPARATED_LIST_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").unwrap());

-/// Parse a comma-separated list of `CheckCodePrefix` values (e.g.,
+/// Parse a comma-separated list of `RuleCodePrefix` values (e.g.,
 /// "F401,E501").
-pub fn parse_prefix_codes(value: &str) -> Vec<CheckCodePrefix> {
-    let mut codes: Vec<CheckCodePrefix> = vec![];
+pub fn parse_prefix_codes(value: &str) -> Vec<RuleCodePrefix> {
+    let mut codes: Vec<RuleCodePrefix> = vec![];
    for code in COMMA_SEPARATED_LIST_RE.split(value) {
        let code = code.trim();
        if code.is_empty() {
@@ -21,10 +22,10 @@ pub fn parse_prefix_codes(value: &str) -> Vec<CheckCodePrefix> {
        }
        if let Some(code) = PREFIX_REDIRECTS.get(code) {
            codes.push(code.clone());
-        } else if let Ok(code) = CheckCodePrefix::from_str(code) {
+        } else if let Ok(code) = RuleCodePrefix::from_str(code) {
            codes.push(code);
        } else {
-            eprintln!("Unsupported prefix code: {code}");
+            warn_user!("Unsupported prefix code: {code}");
        }
    }
    codes
@@ -82,7 +83,8 @@ impl State {
        }
    }

-    /// Generate the list of `StrCheckCodePair` pairs for the current state.
+    /// Generate the list of `StrRuleCodePair` pairs for the current
+    /// state.
    fn parse(&self) -> Vec<PatternPrefixPair> {
        let mut codes: Vec<PatternPrefixPair> = vec![];
        for code in &self.codes {
@@ -93,7 +95,7 @@ impl State {
                        prefix: code.clone(),
                    });
                }
-            } else if let Ok(code) = CheckCodePrefix::from_str(code) {
+            } else if let Ok(code) = RuleCodePrefix::from_str(code) {
                for filename in &self.filenames {
                    codes.push(PatternPrefixPair {
                        pattern: filename.clone(),
@@ -101,7 +103,7 @@ impl State {
                    });
                }
            } else {
-                eprintln!("Unsupported prefix code: {code}");
+                warn_user!("Unsupported prefix code: {code}");
            }
        }
        codes
@@ -128,7 +130,7 @@ fn tokenize_files_to_codes_mapping(value: &str) -> Vec<Token> {
                if mat.start() == 0 {
                    tokens.push(Token {
                        token_name,
-                        src: mat.as_str().to_string().trim().to_string(),
+                        src: mat.as_str().trim().to_string(),
                    });
                    i += mat.end();
                    break;
@@ -187,8 +189,8 @@ pub fn parse_files_to_codes_mapping(value: &str) -> Result<Vec<PatternPrefixPair
 /// Collect a list of `PatternPrefixPair` structs as a `BTreeMap`.
 pub fn collect_per_file_ignores(
    pairs: Vec<PatternPrefixPair>,
-) -> FxHashMap<String, Vec<CheckCodePrefix>> {
-    let mut per_file_ignores: FxHashMap<String, Vec<CheckCodePrefix>> = FxHashMap::default();
+) -> FxHashMap<String, Vec<RuleCodePrefix>> {
+    let mut per_file_ignores: FxHashMap<String, Vec<RuleCodePrefix>> = FxHashMap::default();
    for pair in pairs {
        per_file_ignores
            .entry(pair.pattern)
@@ -201,7 +203,7 @@ pub fn collect_per_file_ignores(
 #[cfg(test)]
 mod tests {
    use anyhow::Result;
-    use ruff::registry_gen::CheckCodePrefix;
+    use ruff::registry::RuleCodePrefix;
    use ruff::settings::types::PatternPrefixPair;

    use crate::parser::{parse_files_to_codes_mapping, parse_prefix_codes, parse_strings};
@@ -209,27 +211,27 @@ mod tests {
    #[test]
    fn it_parses_prefix_codes() {
        let actual = parse_prefix_codes("");
-        let expected: Vec<CheckCodePrefix> = vec![];
+        let expected: Vec<RuleCodePrefix> = vec![];
        assert_eq!(actual, expected);

        let actual = parse_prefix_codes(" ");
-        let expected: Vec<CheckCodePrefix> = vec![];
+        let expected: Vec<RuleCodePrefix> = vec![];
        assert_eq!(actual, expected);

        let actual = parse_prefix_codes("F401");
-        let expected = vec![CheckCodePrefix::F401];
+        let expected = vec![RuleCodePrefix::F401];
        assert_eq!(actual, expected);

        let actual = parse_prefix_codes("F401,");
-        let expected = vec![CheckCodePrefix::F401];
+        let expected = vec![RuleCodePrefix::F401];
        assert_eq!(actual, expected);

        let actual = parse_prefix_codes("F401,E501");
-        let expected = vec![CheckCodePrefix::F401, CheckCodePrefix::E501];
+        let expected = vec![RuleCodePrefix::F401, RuleCodePrefix::E501];
        assert_eq!(actual, expected);

        let actual = parse_prefix_codes("F401, E501");
-        let expected = vec![CheckCodePrefix::F401, CheckCodePrefix::E501];
+        let expected = vec![RuleCodePrefix::F401, RuleCodePrefix::E501];
        assert_eq!(actual, expected);
    }

@@ -282,11 +284,11 @@ mod tests {
        let expected: Vec<PatternPrefixPair> = vec![
            PatternPrefixPair {
                pattern: "locust/test/*".to_string(),
-                prefix: CheckCodePrefix::F841,
+                prefix: RuleCodePrefix::F841,
            },
            PatternPrefixPair {
                pattern: "examples/*".to_string(),
-                prefix: CheckCodePrefix::F841,
+                prefix: RuleCodePrefix::F841,
            },
        ];
        assert_eq!(actual, expected);
@@ -302,23 +304,23 @@ mod tests {
        let expected: Vec<PatternPrefixPair> = vec![
            PatternPrefixPair {
                pattern: "t/*".to_string(),
-                prefix: CheckCodePrefix::D,
+                prefix: RuleCodePrefix::D,
            },
            PatternPrefixPair {
                pattern: "setup.py".to_string(),
-                prefix: CheckCodePrefix::D,
+                prefix: RuleCodePrefix::D,
            },
            PatternPrefixPair {
                pattern: "examples/*".to_string(),
-                prefix: CheckCodePrefix::D,
+                prefix: RuleCodePrefix::D,
            },
            PatternPrefixPair {
                pattern: "docs/*".to_string(),
-                prefix: CheckCodePrefix::D,
+                prefix: RuleCodePrefix::D,
            },
            PatternPrefixPair {
                pattern: "extra/*".to_string(),
-                prefix: CheckCodePrefix::D,
+                prefix: RuleCodePrefix::D,
            },
        ];
        assert_eq!(actual, expected);
@@ -340,47 +342,47 @@ mod tests {
        let expected: Vec<PatternPrefixPair> = vec![
            PatternPrefixPair {
                pattern: "scrapy/__init__.py".to_string(),
-                prefix: CheckCodePrefix::E402,
+                prefix: RuleCodePrefix::E402,
            },
            PatternPrefixPair {
                pattern: "scrapy/core/downloader/handlers/http.py".to_string(),
-                prefix: CheckCodePrefix::F401,
+                prefix: RuleCodePrefix::F401,
            },
            PatternPrefixPair {
                pattern: "scrapy/http/__init__.py".to_string(),
-                prefix: CheckCodePrefix::F401,
+                prefix: RuleCodePrefix::F401,
            },
            PatternPrefixPair {
                pattern: "scrapy/linkextractors/__init__.py".to_string(),
-                prefix: CheckCodePrefix::E402,
+                prefix: RuleCodePrefix::E402,
            },
            PatternPrefixPair {
                pattern: "scrapy/linkextractors/__init__.py".to_string(),
-                prefix: CheckCodePrefix::F401,
+                prefix: RuleCodePrefix::F401,
            },
            PatternPrefixPair {
                pattern: "scrapy/selector/__init__.py".to_string(),
-                prefix: CheckCodePrefix::F401,
+                prefix: RuleCodePrefix::F401,
            },
            PatternPrefixPair {
                pattern: "scrapy/spiders/__init__.py".to_string(),
-                prefix: CheckCodePrefix::E402,
+                prefix: RuleCodePrefix::E402,
            },
            PatternPrefixPair {
                pattern: "scrapy/spiders/__init__.py".to_string(),
-                prefix: CheckCodePrefix::F401,
+                prefix: RuleCodePrefix::F401,
            },
            PatternPrefixPair {
                pattern: "scrapy/utils/url.py".to_string(),
-                prefix: CheckCodePrefix::F403,
+                prefix: RuleCodePrefix::F403,
            },
            PatternPrefixPair {
                pattern: "scrapy/utils/url.py".to_string(),
-                prefix: CheckCodePrefix::F405,
+                prefix: RuleCodePrefix::F405,
            },
            PatternPrefixPair {
                pattern: "tests/test_loader.py".to_string(),
-                prefix: CheckCodePrefix::E741,
+                prefix: RuleCodePrefix::E741,
            },
        ];
        assert_eq!(actual, expected);
--- a/flake8_to_ruff/src/plugin.rs
+++ b/flake8_to_ruff/src/plugin.rs
@@ -3,7 +3,7 @@ use std::fmt;
 use std::str::FromStr;

 use anyhow::anyhow;
-use ruff::registry_gen::CheckCodePrefix;
+use ruff::registry::RuleCodePrefix;

 #[derive(Clone, Ord, PartialOrd, Eq, PartialEq)]
 pub enum Plugin {
@@ -97,53 +97,32 @@ impl fmt::Debug for Plugin {
 }

 impl Plugin {
-    pub fn prefix(&self) -> CheckCodePrefix {
+    pub fn prefix(&self) -> RuleCodePrefix {
        match self {
-            Plugin::Flake8Annotations => CheckCodePrefix::ANN,
-            Plugin::Flake8Bandit => CheckCodePrefix::S,
+            Plugin::Flake8Annotations => RuleCodePrefix::ANN,
+            Plugin::Flake8Bandit => RuleCodePrefix::S,
            // TODO(charlie): Handle rename of `B` to `BLE`.
-            Plugin::Flake8BlindExcept => CheckCodePrefix::BLE,
-            Plugin::Flake8Bugbear => CheckCodePrefix::B,
-            Plugin::Flake8Builtins => CheckCodePrefix::A,
-            Plugin::Flake8Comprehensions => CheckCodePrefix::C4,
-            Plugin::Flake8Datetimez => CheckCodePrefix::DTZ,
-            Plugin::Flake8Debugger => CheckCodePrefix::T1,
-            Plugin::Flake8Docstrings => CheckCodePrefix::D,
+            Plugin::Flake8BlindExcept => RuleCodePrefix::BLE,
+            Plugin::Flake8Bugbear => RuleCodePrefix::B,
+            Plugin::Flake8Builtins => RuleCodePrefix::A,
+            Plugin::Flake8Comprehensions => RuleCodePrefix::C4,
+            Plugin::Flake8Datetimez => RuleCodePrefix::DTZ,
+            Plugin::Flake8Debugger => RuleCodePrefix::T1,
+            Plugin::Flake8Docstrings => RuleCodePrefix::D,
            // TODO(charlie): Handle rename of `E` to `ERA`.
-            Plugin::Flake8Eradicate => CheckCodePrefix::ERA,
-            Plugin::Flake8ErrMsg => CheckCodePrefix::EM,
-            Plugin::Flake8ImplicitStrConcat => CheckCodePrefix::ISC,
-            Plugin::Flake8Print => CheckCodePrefix::T2,
-            Plugin::Flake8PytestStyle => CheckCodePrefix::PT,
-            Plugin::Flake8Quotes => CheckCodePrefix::Q,
-            Plugin::Flake8Return => CheckCodePrefix::RET,
-            Plugin::Flake8Simplify => CheckCodePrefix::SIM,
-            Plugin::Flake8TidyImports => CheckCodePrefix::TID25,
-            Plugin::McCabe => CheckCodePrefix::C9,
-            Plugin::PandasVet => CheckCodePrefix::PD,
-            Plugin::PEP8Naming => CheckCodePrefix::N,
-            Plugin::Pyupgrade => CheckCodePrefix::UP,
-        }
-    }
-}
-
-pub enum DocstringConvention {
-    All,
-    Pep257,
-    Numpy,
-    Google,
-}
-
-impl FromStr for DocstringConvention {
-    type Err = anyhow::Error;
-
-    fn from_str(string: &str) -> Result<Self, Self::Err> {
-        match string {
-            "all" => Ok(DocstringConvention::All),
-            "pep257" => Ok(DocstringConvention::Pep257),
-            "numpy" => Ok(DocstringConvention::Numpy),
-            "google" => Ok(DocstringConvention::Google),
-            _ => Err(anyhow!("Unknown docstring convention: {string}")),
+            Plugin::Flake8Eradicate => RuleCodePrefix::ERA,
+            Plugin::Flake8ErrMsg => RuleCodePrefix::EM,
+            Plugin::Flake8ImplicitStrConcat => RuleCodePrefix::ISC,
+            Plugin::Flake8Print => RuleCodePrefix::T2,
+            Plugin::Flake8PytestStyle => RuleCodePrefix::PT,
+            Plugin::Flake8Quotes => RuleCodePrefix::Q,
+            Plugin::Flake8Return => RuleCodePrefix::RET,
+            Plugin::Flake8Simplify => RuleCodePrefix::SIM,
+            Plugin::Flake8TidyImports => RuleCodePrefix::TID25,
+            Plugin::McCabe => RuleCodePrefix::C9,
+            Plugin::PandasVet => RuleCodePrefix::PD,
+            Plugin::PEP8Naming => RuleCodePrefix::N,
+            Plugin::Pyupgrade => RuleCodePrefix::UP,
        }
    }
 }
@@ -269,7 +248,7 @@ pub fn infer_plugins_from_options(flake8: &HashMap<String, Option<String>>) -> V
 ///
 /// For example, if the user ignores `ANN101`, we should infer that
 /// `flake8-annotations` is active.
-pub fn infer_plugins_from_codes(codes: &BTreeSet<CheckCodePrefix>) -> Vec<Plugin> {
+pub fn infer_plugins_from_codes(codes: &BTreeSet<RuleCodePrefix>) -> Vec<Plugin> {
    [
        Plugin::Flake8Annotations,
        Plugin::Flake8Bandit,
@@ -307,9 +286,10 @@ pub fn infer_plugins_from_codes(codes: &BTreeSet<CheckCodePrefix>) -> Vec<Plugin
    .collect()
 }

-/// Resolve the set of enabled `CheckCodePrefix` values for the given plugins.
-pub fn resolve_select(plugins: &[Plugin]) -> BTreeSet<CheckCodePrefix> {
-    let mut select = BTreeSet::from([CheckCodePrefix::F, CheckCodePrefix::E, CheckCodePrefix::W]);
+/// Resolve the set of enabled `RuleCodePrefix` values for the given
+/// plugins.
+pub fn resolve_select(plugins: &[Plugin]) -> BTreeSet<RuleCodePrefix> {
+    let mut select = BTreeSet::from([RuleCodePrefix::F, RuleCodePrefix::E, RuleCodePrefix::W]);
    select.extend(plugins.iter().map(Plugin::prefix));
    select
 }
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "maturin"

 [project]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.216"
 description = "An extremely fast Python linter, written in Rust."
 authors = [
  { name = "Charlie Marsh", email = "charlie.r.marsh@gmail.com" },
--- a/resources/test/fixtures/flake8_bandit/S113.py
+++ b/resources/test/fixtures/flake8_bandit/S113.py
@@ -0,0 +1,23 @@
+import requests
+
+requests.get('https://gmail.com')
+requests.get('https://gmail.com', timeout=None)
+requests.get('https://gmail.com', timeout=5)
+requests.post('https://gmail.com')
+requests.post('https://gmail.com', timeout=None)
+requests.post('https://gmail.com', timeout=5)
+requests.put('https://gmail.com')
+requests.put('https://gmail.com', timeout=None)
+requests.put('https://gmail.com', timeout=5)
+requests.delete('https://gmail.com')
+requests.delete('https://gmail.com', timeout=None)
+requests.delete('https://gmail.com', timeout=5)
+requests.patch('https://gmail.com')
+requests.patch('https://gmail.com', timeout=None)
+requests.patch('https://gmail.com', timeout=5)
+requests.options('https://gmail.com')
+requests.options('https://gmail.com', timeout=None)
+requests.options('https://gmail.com', timeout=5)
+requests.head('https://gmail.com')
+requests.head('https://gmail.com', timeout=None)
+requests.head('https://gmail.com', timeout=5)
--- a/resources/test/fixtures/flake8_bandit/S324.py
+++ b/resources/test/fixtures/flake8_bandit/S324.py
@@ -0,0 +1,52 @@
+import hashlib
+from hashlib import new as hashlib_new
+from hashlib import sha1 as hashlib_sha1
+
+# Invalid
+
+hashlib.new('md5')
+
+hashlib.new('md4', b'test')
+
+hashlib.new(name='md5', data=b'test')
+
+hashlib.new('MD4', data=b'test')
+
+hashlib.new('sha1')
+
+hashlib.new('sha1', data=b'test')
+
+hashlib.new('sha', data=b'test')
+
+hashlib.new(name='SHA', data=b'test')
+
+hashlib.sha(data=b'test')
+
+hashlib.md5()
+
+hashlib_new('sha1')
+
+hashlib_sha1('sha1')
+
+# usedforsecurity arg only available in Python 3.9+
+hashlib.new('sha1', usedforsecurity=True)
+
+# Valid
+
+hashlib.new('sha256')
+
+hashlib.new('SHA512')
+
+hashlib.sha256(data=b'test')
+
+# usedforsecurity arg only available in Python 3.9+
+hashlib_new(name='sha1', usedforsecurity=False)
+
+# usedforsecurity arg only available in Python 3.9+
+hashlib_sha1(name='sha1', usedforsecurity=False)
+
+# usedforsecurity arg only available in Python 3.9+
+hashlib.md4(usedforsecurity=False)
+
+# usedforsecurity arg only available in Python 3.9+
+hashlib.new(name='sha256', usedforsecurity=False)
--- a/resources/test/fixtures/flake8_bandit/S501.py
+++ b/resources/test/fixtures/flake8_bandit/S501.py
@@ -0,0 +1,40 @@
+import httpx
+import requests
+
+requests.get('https://gmail.com', timeout=30, verify=True)
+requests.get('https://gmail.com', timeout=30, verify=False)
+requests.post('https://gmail.com', timeout=30, verify=True)
+requests.post('https://gmail.com', timeout=30, verify=False)
+requests.put('https://gmail.com', timeout=30, verify=True)
+requests.put('https://gmail.com', timeout=30, verify=False)
+requests.delete('https://gmail.com', timeout=30, verify=True)
+requests.delete('https://gmail.com', timeout=30, verify=False)
+requests.patch('https://gmail.com', timeout=30, verify=True)
+requests.patch('https://gmail.com', timeout=30, verify=False)
+requests.options('https://gmail.com', timeout=30, verify=True)
+requests.options('https://gmail.com', timeout=30, verify=False)
+requests.head('https://gmail.com', timeout=30, verify=True)
+requests.head('https://gmail.com', timeout=30, verify=False)
+
+httpx.request('GET', 'https://gmail.com', verify=True)
+httpx.request('GET', 'https://gmail.com', verify=False)
+httpx.get('https://gmail.com', verify=True)
+httpx.get('https://gmail.com', verify=False)
+httpx.options('https://gmail.com', verify=True)
+httpx.options('https://gmail.com', verify=False)
+httpx.head('https://gmail.com', verify=True)
+httpx.head('https://gmail.com', verify=False)
+httpx.post('https://gmail.com', verify=True)
+httpx.post('https://gmail.com', verify=False)
+httpx.put('https://gmail.com', verify=True)
+httpx.put('https://gmail.com', verify=False)
+httpx.patch('https://gmail.com', verify=True)
+httpx.patch('https://gmail.com', verify=False)
+httpx.delete('https://gmail.com', verify=True)
+httpx.delete('https://gmail.com', verify=False)
+httpx.stream('https://gmail.com', verify=True)
+httpx.stream('https://gmail.com', verify=False)
+httpx.Client()
+httpx.Client(verify=False)
+httpx.AsyncClient()
+httpx.AsyncClient(verify=False)
--- a/resources/test/fixtures/flake8_bandit/S506.py
+++ b/resources/test/fixtures/flake8_bandit/S506.py
@@ -0,0 +1,31 @@
+import json
+import yaml
+from yaml import CSafeLoader
+from yaml import SafeLoader
+from yaml import SafeLoader as NewSafeLoader
+
+
+def test_yaml_load():
+    ystr = yaml.dump({"a": 1, "b": 2, "c": 3})
+    y = yaml.load(ystr)
+    yaml.dump(y)
+    try:
+        y = yaml.load(ystr, Loader=yaml.CSafeLoader)
+    except AttributeError:
+        # CSafeLoader only exists if you build yaml with LibYAML
+        y = yaml.load(ystr, Loader=yaml.SafeLoader)
+
+
+def test_json_load():
+    # no issue should be found
+    j = json.load("{}")
+
+
+yaml.load("{}", Loader=yaml.Loader)
+
+# no issue should be found
+yaml.load("{}", SafeLoader)
+yaml.load("{}", yaml.SafeLoader)
+yaml.load("{}", CSafeLoader)
+yaml.load("{}", yaml.CSafeLoader)
+yaml.load("{}", NewSafeLoader)
--- a/resources/test/fixtures/flake8_pytest_style/PT009.py
+++ b/resources/test/fixtures/flake8_pytest_style/PT009.py
@@ -1,9 +1,76 @@
-import pytest
+import unittest


-def test_xxx():
-    assert 1 == 1  # OK no parameters
+class Test(unittest.TestCase):
+    def test_xxx(self):
+        assert 1 == 1  # OK no parameters

+    def test_assert_true(self):
+        expr = 1
+        msg = "Must be True"
+        self.assertTrue(expr)  # Error
+        self.assertTrue(expr=expr)  # Error
+        self.assertTrue(expr, msg)  # Error
+        self.assertTrue(expr=expr, msg=msg)  # Error
+        self.assertTrue(msg=msg, expr=expr)  # Error
+        self.assertTrue(*(expr, msg))  # Error, unfixable
+        self.assertTrue(**{"expr": expr, "msg": msg})  # Error, unfixable
+        self.assertTrue(msg=msg, expr=expr, unexpected_arg=False)  # Error, unfixable
+        self.assertTrue(msg=msg)  # Error, unfixable

-def test_xxx():
-    self.assertEqual(1, 1)  # Error
+    def test_assert_false(self):
+        self.assertFalse(True)  # Error
+
+    def test_assert_equal(self):
+        self.assertEqual(1, 2)  # Error
+
+    def test_assert_not_equal(self):
+        self.assertNotEqual(1, 1)  # Error
+
+    def test_assert_greater(self):
+        self.assertGreater(1, 2)  # Error
+
+    def test_assert_greater_equal(self):
+        self.assertGreaterEqual(1, 2)  # Error
+
+    def test_assert_less(self):
+        self.assertLess(2, 1)  # Error
+
+    def test_assert_less_equal(self):
+        self.assertLessEqual(1, 2)  # Error
+
+    def test_assert_in(self):
+        self.assertIn(1, [2, 3])  # Error
+
+    def test_assert_not_in(self):
+        self.assertNotIn(2, [2, 3])  # Error
+
+    def test_assert_is_none(self):
+        self.assertIsNone(0)  # Error
+
+    def test_assert_is_not_none(self):
+        self.assertIsNotNone(0)  # Error
+
+    def test_assert_is(self):
+        self.assertIs([], [])  # Error
+
+    def test_assert_is_not(self):
+        self.assertIsNot(1, 1)  # Error
+
+    def test_assert_is_instance(self):
+        self.assertIsInstance(1, str)  # Error
+
+    def test_assert_is_not_instance(self):
+        self.assertNotIsInstance(1, int)  # Error
+
+    def test_assert_regex(self):
+        self.assertRegex("abc", r"def")  # Error
+
+    def test_assert_not_regex(self):
+        self.assertNotRegex("abc", r"abc")  # Error
+
+    def test_assert_regexp_matches(self):
+        self.assertRegexpMatches("abc", r"def")  # Error
+
+    def test_assert_not_regexp_matches(self):
+        self.assertNotRegex("abc", r"abc")  # Error
--- a/resources/test/fixtures/flake8_simplify/SIM101.py
+++ b/resources/test/fixtures/flake8_simplify/SIM101.py
@@ -0,0 +1,23 @@
+if isinstance(a, int) or isinstance(a, float):  # SIM101
+    pass
+
+if isinstance(a, (int, float)) or isinstance(a, bool):  # SIM101
+    pass
+
+if isinstance(a, int) or isinstance(a, float) or isinstance(b, bool):  # SIM101
+    pass
+
+if isinstance(b, bool) or isinstance(a, int) or isinstance(a, float):  # SIM101
+    pass
+
+if isinstance(a, int) or isinstance(b, bool) or isinstance(a, float):  # SIM101
+    pass
+
+if (isinstance(a, int) or isinstance(a, float)) and isinstance(b, bool):  # SIM101
+    pass
+
+if isinstance(a, int) and isinstance(b, bool) or isinstance(a, float):
+    pass
+
+if isinstance(a, bool) or isinstance(b, str):
+    pass
--- a/resources/test/fixtures/flake8_simplify/SIM103.py
+++ b/resources/test/fixtures/flake8_simplify/SIM103.py
@@ -0,0 +1,20 @@
+def f():
+    if a:  # SIM103
+        return True
+    else:
+        return False
+
+
+def f():
+    if a:  # OK
+        foo()
+        return True
+    else:
+        return False
+
+
+def f():
+    if a:  # OK
+        return "foo"
+    else:
+        return False
--- a/resources/test/fixtures/flake8_simplify/SIM108.py
+++ b/resources/test/fixtures/flake8_simplify/SIM108.py
@@ -0,0 +1,31 @@
+# Bad
+if a:
+    b = c
+else:
+    b = d
+
+# Good
+b = c if a else d
+
+# https://github.com/MartinThoma/flake8-simplify/issues/115
+if a:
+    b = c
+elif c:
+    b = a
+else:
+    b = d
+
+if True:
+    pass
+elif a:
+    b = 1
+else:
+    b = 2
+
+if True:
+    pass
+else:
+    if a:
+        b = 1
+    else:
+        b = 2
--- a/resources/test/fixtures/flake8_simplify/SIM109.py
+++ b/resources/test/fixtures/flake8_simplify/SIM109.py
@@ -0,0 +1,7 @@
+# Bad
+if a == b or a == c:
+    d
+
+# Good
+if a in (b, c):
+    d
--- a/resources/test/fixtures/flake8_simplify/SIM201.py
+++ b/resources/test/fixtures/flake8_simplify/SIM201.py
@@ -0,0 +1,17 @@
+if not a == b:  # SIM201
+    pass
+
+if not a == (b + c):  # SIM201
+    pass
+
+if not (a + b) == c:  # SIM201
+    pass
+
+if not a != b:  # OK
+    pass
+
+if a == b:  # OK
+    pass
+
+if not a == b:  # OK
+    raise ValueError()
--- a/resources/test/fixtures/flake8_simplify/SIM202.py
+++ b/resources/test/fixtures/flake8_simplify/SIM202.py
@@ -0,0 +1,14 @@
+if not a != b:  # SIM202
+    pass
+
+if not a != (b + c):  # SIM202
+    pass
+
+if not (a + b) != c:  # SIM202
+    pass
+
+if not a == b:  # OK
+    pass
+
+if a != b:  # OK
+    pass
--- a/resources/test/fixtures/flake8_simplify/SIM208.py
+++ b/resources/test/fixtures/flake8_simplify/SIM208.py
@@ -0,0 +1,14 @@
+if not (not a):  # SIM208
+    pass
+
+if not (not (a == b)):  # SIM208
+    pass
+
+if not a:  # OK
+    pass
+
+if not a == b:  # OK
+    pass
+
+if not a != b:  # OK
+    pass
--- a/resources/test/fixtures/flake8_simplify/SIM210.py
+++ b/resources/test/fixtures/flake8_simplify/SIM210.py
@@ -0,0 +1,7 @@
+a = True if b else False  # SIM210
+
+a = True if b != c else False  # SIM210
+
+a = True if b + c else False  # SIM210
+
+a = False if b else True  # OK
--- a/resources/test/fixtures/flake8_simplify/SIM211.py
+++ b/resources/test/fixtures/flake8_simplify/SIM211.py
@@ -0,0 +1,7 @@
+a = False if b else True  # SIM211
+
+a = False if b != c else True  # SIM211
+
+a = False if b + c else True  # SIM211
+
+a = True if b else False  # OK
--- a/resources/test/fixtures/flake8_simplify/SIM212.py
+++ b/resources/test/fixtures/flake8_simplify/SIM212.py
@@ -0,0 +1,7 @@
+c = b if not a else a  # SIM212
+
+c = b + c if not a else a  # SIM212
+
+c = b if not x else a  # OK
+
+c = a if a else b  # OK
--- a/resources/test/fixtures/flake8_unused_arguments/ARG.py
+++ b/resources/test/fixtures/flake8_unused_arguments/ARG.py
@@ -77,6 +77,34 @@ class C:
    def f(x):
        ...

+    def f(self, x):
+        """Docstring."""
+
+    def f(self, x):
+        """Docstring."""
+        ...
+
+    def f(self, x):
+        pass
+
+    def f(self, x):
+        raise NotImplementedError
+
+    def f(self, x):
+        raise NotImplementedError()
+
+    def f(self, x):
+        raise NotImplementedError("...")
+
+    def f(self, x):
+        raise NotImplemented
+
+    def f(self, x):
+        raise NotImplemented()
+
+    def f(self, x):
+        raise NotImplemented("...")
+
    ###
    # Unused functions attached to abstract methods (OK).
    ###
--- a/resources/test/fixtures/isort/force_sort_within_sections.py
+++ b/resources/test/fixtures/isort/force_sort_within_sections.py
@@ -0,0 +1,11 @@
+from a import a1  # import_from
+from c import * # import_from_star
+import a  # import
+import c.d
+import b as b1  # import_as
+
+from ..parent import *
+from .my import fn
+from . import my
+from .my.nested import fn2
+from ...grandparent import fn3
--- a/resources/test/fixtures/isort/skip.py
+++ b/resources/test/fixtures/isort/skip.py
@@ -1,10 +1,20 @@
-# isort: off
-import sys
-import os
-import collections
-# isort: on
+def f():
+    # isort: off
+    import sys
+    import os
+    import collections
+    # isort: on

-import sys
-import os  # isort: skip
-import collections
-import abc
+
+def f():
+    import sys
+    import os  # isort: skip
+    import collections
+    import abc
+
+
+def f():
+    import sys
+    import os  # isort:skip
+    import collections
+    import abc
--- a/resources/test/fixtures/isort/split.py
+++ b/resources/test/fixtures/isort/split.py
@@ -3,7 +3,10 @@ import f

 # isort: split

-import a
-import b
 import c
 import d
+
+# isort: split  
+
+import a
+import b
--- a/resources/test/fixtures/pycodestyle/E999.py
+++ b/resources/test/fixtures/pycodestyle/E999.py
@@ -1,2 +1,4 @@
+
 def x():

+
--- a/resources/test/fixtures/pyflakes/F601.py
+++ b/resources/test/fixtures/pyflakes/F601.py
@@ -10,3 +10,41 @@ x = {
    b"123": 1,
    b"123": 4,
 }
+
+x = {
+    "a": 1,
+    "a": 2,
+    "a": 3,
+    "a": 3,
+}
+
+x = {
+    "a": 1,
+    "a": 2,
+    "a": 3,
+    "a": 3,
+    "a": 4,
+}
+
+x = {
+    "a": 1,
+    "a": 1,
+    "a": 2,
+    "a": 3,
+    "a": 4,
+}
+
+x = {
+    a: 1,
+    "a": 1,
+    a: 1,
+    "a": 2,
+    a: 2,
+    "a": 3,
+    a: 3,
+    "a": 3,
+    a: 4,
+}
+
+x = {"a": 1, "a": 1}
+x = {"a": 1, "b": 2, "a": 1}
--- a/resources/test/fixtures/pyflakes/F602.py
+++ b/resources/test/fixtures/pyflakes/F602.py
@@ -5,3 +5,41 @@ x = {
    a: 2,
    b: 3,
 }
+
+x = {
+    a: 1,
+    a: 2,
+    a: 3,
+    a: 3,
+}
+
+x = {
+    a: 1,
+    a: 2,
+    a: 3,
+    a: 3,
+    a: 4,
+}
+
+x = {
+    a: 1,
+    a: 1,
+    a: 2,
+    a: 3,
+    a: 4,
+}
+
+x = {
+    a: 1,
+    "a": 1,
+    a: 1,
+    "a": 2,
+    a: 2,
+    "a": 3,
+    a: 3,
+    "a": 3,
+    a: 4,
+}
+
+x = {a: 1, a: 1}
+x = {a: 1, b: 2, a: 1}
--- a/resources/test/fixtures/pyflakes/F841_3.py
+++ b/resources/test/fixtures/pyflakes/F841_3.py
@@ -0,0 +1,46 @@
+"""Test case for autofixing F841 violations."""
+
+
+def f():
+    x = 1
+    y = 2
+
+    z = 3
+    print(z)
+
+
+def f():
+    x: int = 1
+    y: int = 2
+
+    z: int = 3
+    print(z)
+
+
+def f():
+    with foo() as x1:
+        pass
+
+    with foo() as (x2, y2):
+        pass
+
+    with (foo() as x3, foo() as y3, foo() as z3):
+        pass
+
+
+def f():
+    (x1, y1) = (1, 2)
+    (x2, y2) = coords2 = (1, 2)
+    coords3 = (x3, y3) = (1, 2)
+
+
+def f():
+    try:
+        1 / 0
+    except ValueError as x1:
+        pass
+
+    try:
+        1 / 0
+    except (ValueError, ZeroDivisionError) as x2:
+        pass
--- a/resources/test/fixtures/pyflakes/builtins.py
+++ b/resources/test/fixtures/pyflakes/builtins.py
@@ -0,0 +1 @@
+_("Translations")
--- a/resources/test/fixtures/pyupgrade/UP028_1.py
+++ b/resources/test/fixtures/pyupgrade/UP028_1.py
@@ -111,3 +111,13 @@ def f():
    class C:
        def __init__(self):
            print(x)
+
+
+def f():
+    for x in y:
+        yield x, x + 1
+
+
+def f():
+    for x, y in z:
+        yield x, y, x + y
--- a/ruff.schema.json
+++ b/ruff.schema.json
--- a/ruff_dev/Cargo.toml
+++ b/ruff_dev/Cargo.toml
@@ -1,19 +1,18 @@
 [package]
 name = "ruff_dev"
-version = "0.0.211"
+version = "0.0.216"
 edition = "2021"

 [dependencies]
 anyhow = { version = "1.0.66" }
 clap = { version = "4.0.1", features = ["derive"] }
-codegen = { version = "0.2.0" }
 itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
 once_cell = { version = "1.16.0" }
 ruff = { path = ".." }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "4d53c7cb27c0379adf8b51c4d3d0d2174f41d590" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "4d53c7cb27c0379adf8b51c4d3d0d2174f41d590" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "4d53c7cb27c0379adf8b51c4d3d0d2174f41d590" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "d532160333ffeb6dbeca2c2728c2391cd1e53b7f" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "d532160333ffeb6dbeca2c2728c2391cd1e53b7f" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "d532160333ffeb6dbeca2c2728c2391cd1e53b7f" }
 schemars = { version = "0.8.11" }
 serde_json = {version="1.0.91"}
 strum = { version = "0.24.1", features = ["strum_macros"] }
--- a/ruff_dev/src/generate_all.rs
+++ b/ruff_dev/src/generate_all.rs
@@ -3,10 +3,7 @@
 use anyhow::Result;
 use clap::Args;

-use crate::{
-    generate_check_code_prefix, generate_cli_help, generate_json_schema, generate_options,
-    generate_rules_table,
-};
+use crate::{generate_cli_help, generate_json_schema, generate_options, generate_rules_table};

 #[derive(Args)]
 pub struct Cli {
@@ -16,9 +13,6 @@ pub struct Cli {
 }

 pub fn main(cli: &Cli) -> Result<()> {
-    generate_check_code_prefix::main(&generate_check_code_prefix::Cli {
-        dry_run: cli.dry_run,
-    })?;
    generate_json_schema::main(&generate_json_schema::Cli {
        dry_run: cli.dry_run,
    })?;
--- a/ruff_dev/src/generate_check_code_prefix.rs
+++ b/ruff_dev/src/generate_check_code_prefix.rs
@@ -1,221 +0,0 @@
-//! Generate the `CheckCodePrefix` enum.
-
-use std::collections::{BTreeMap, BTreeSet};
-use std::fs;
-use std::io::Write;
-use std::path::PathBuf;
-use std::process::{Command, Output, Stdio};
-
-use anyhow::{ensure, Result};
-use clap::Parser;
-use codegen::{Scope, Type, Variant};
-use itertools::Itertools;
-use ruff::registry::{CheckCode, PREFIX_REDIRECTS};
-use strum::IntoEnumIterator;
-
-const ALL: &str = "ALL";
-
-#[derive(Parser)]
-#[command(author, version, about, long_about = None)]
-pub struct Cli {
-    /// Write the generated source code to stdout (rather than to
-    /// `src/registry_gen.rs`).
-    #[arg(long)]
-    pub(crate) dry_run: bool,
-}
-
-pub fn main(cli: &Cli) -> Result<()> {
-    // Build up a map from prefix to matching CheckCodes.
-    let mut prefix_to_codes: BTreeMap<String, BTreeSet<CheckCode>> = BTreeMap::default();
-    for check_code in CheckCode::iter() {
-        let code_str: String = check_code.as_ref().to_string();
-        let code_prefix_len = code_str
-            .chars()
-            .take_while(|char| char.is_alphabetic())
-            .count();
-        let code_suffix_len = code_str.len() - code_prefix_len;
-        for i in 0..=code_suffix_len {
-            let prefix = code_str[..code_prefix_len + i].to_string();
-            prefix_to_codes
-                .entry(prefix)
-                .or_default()
-                .insert(check_code.clone());
-        }
-        prefix_to_codes
-            .entry(ALL.to_string())
-            .or_default()
-            .insert(check_code.clone());
-    }
-
-    // Add any prefix aliases (e.g., "U" to "UP").
-    for (alias, check_code) in PREFIX_REDIRECTS.iter() {
-        prefix_to_codes.insert(
-            (*alias).to_string(),
-            prefix_to_codes
-                .get(&check_code.as_ref().to_string())
-                .unwrap_or_else(|| panic!("Unknown CheckCode: {alias:?}"))
-                .clone(),
-        );
-    }
-
-    let mut scope = Scope::new();
-
-    // Create the `CheckCodePrefix` definition.
-    let mut gen = scope
-        .new_enum("CheckCodePrefix")
-        .vis("pub")
-        .derive("EnumString")
-        .derive("AsRefStr")
-        .derive("Debug")
-        .derive("PartialEq")
-        .derive("Eq")
-        .derive("PartialOrd")
-        .derive("Ord")
-        .derive("Clone")
-        .derive("Serialize")
-        .derive("Deserialize")
-        .derive("JsonSchema");
-    for prefix in prefix_to_codes.keys() {
-        gen = gen.push_variant(Variant::new(prefix.to_string()));
-    }
-
-    // Create the `SuffixLength` definition.
-    scope
-        .new_enum("SuffixLength")
-        .vis("pub")
-        .derive("PartialEq")
-        .derive("Eq")
-        .derive("PartialOrd")
-        .derive("Ord")
-        .push_variant(Variant::new("None"))
-        .push_variant(Variant::new("Zero"))
-        .push_variant(Variant::new("One"))
-        .push_variant(Variant::new("Two"))
-        .push_variant(Variant::new("Three"))
-        .push_variant(Variant::new("Four"));
-
-    // Create the `match` statement, to map from definition to relevant codes.
-    let mut gen = scope
-        .new_impl("CheckCodePrefix")
-        .new_fn("codes")
-        .arg_ref_self()
-        .ret(Type::new("Vec<CheckCode>"))
-        .vis("pub")
-        .line("#[allow(clippy::match_same_arms)]")
-        .line("match self {");
-    for (prefix, codes) in &prefix_to_codes {
-        if let Some(target) = PREFIX_REDIRECTS.get(&prefix.as_str()) {
-            gen = gen.line(format!(
-                "CheckCodePrefix::{prefix} => {{ one_time_warning!(\"{{}}{{}} {{}}\", \
-                 \"warning\".yellow().bold(), \":\".bold(), \"`{}` has been remapped to \
-                 `{}`\".bold()); \n vec![{}] }}",
-                prefix,
-                target.as_ref(),
-                codes
-                    .iter()
-                    .map(|code| format!("CheckCode::{}", code.as_ref()))
-                    .join(", ")
-            ));
-        } else {
-            gen = gen.line(format!(
-                "CheckCodePrefix::{prefix} => vec![{}],",
-                codes
-                    .iter()
-                    .map(|code| format!("CheckCode::{}", code.as_ref()))
-                    .join(", ")
-            ));
-        }
-    }
-    gen.line("}");
-
-    // Create the `match` statement, to map from definition to specificity.
-    let mut gen = scope
-        .new_impl("CheckCodePrefix")
-        .new_fn("specificity")
-        .arg_ref_self()
-        .ret(Type::new("SuffixLength"))
-        .vis("pub")
-        .line("#[allow(clippy::match_same_arms)]")
-        .line("match self {");
-    for prefix in prefix_to_codes.keys() {
-        let specificity = if prefix == "ALL" {
-            "None"
-        } else {
-            let num_numeric = prefix.chars().filter(|char| char.is_numeric()).count();
-            match num_numeric {
-                0 => "Zero",
-                1 => "One",
-                2 => "Two",
-                3 => "Three",
-                4 => "Four",
-                _ => panic!("Invalid prefix: {prefix}"),
-            }
-        };
-        gen = gen.line(format!(
-            "CheckCodePrefix::{prefix} => SuffixLength::{specificity},"
-        ));
-    }
-    gen.line("}");
-
-    // Construct the output contents.
-    let mut output = String::new();
-    output
-        .push_str("//! File automatically generated by `examples/generate_check_code_prefix.rs`.");
-    output.push('\n');
-    output.push('\n');
-    output.push_str("use colored::Colorize;");
-    output.push('\n');
-    output.push_str("use schemars::JsonSchema;");
-    output.push('\n');
-    output.push_str("use serde::{Deserialize, Serialize};");
-    output.push('\n');
-    output.push_str("use strum_macros::{AsRefStr, EnumString};");
-    output.push('\n');
-    output.push('\n');
-    output.push_str("use crate::registry::CheckCode;");
-    output.push('\n');
-    output.push_str("use crate::one_time_warning;");
-    output.push('\n');
-    output.push('\n');
-    output.push_str(&scope.to_string());
-    output.push('\n');
-    output.push('\n');
-
-    // Add the list of output categories (not generated).
-    output.push_str("pub const CATEGORIES: &[CheckCodePrefix] = &[");
-    output.push('\n');
-    for prefix in prefix_to_codes.keys() {
-        if prefix.chars().all(char::is_alphabetic)
-            && !PREFIX_REDIRECTS.contains_key(&prefix.as_str())
-        {
-            output.push_str(&format!("CheckCodePrefix::{prefix},"));
-            output.push('\n');
-        }
-    }
-    output.push_str("];");
-    output.push('\n');
-    output.push('\n');
-
-    let rustfmt = Command::new("rustfmt")
-        .stdin(Stdio::piped())
-        .stdout(Stdio::piped())
-        .spawn()?;
-    write!(rustfmt.stdin.as_ref().unwrap(), "{output}")?;
-    let Output { status, stdout, .. } = rustfmt.wait_with_output()?;
-    ensure!(status.success(), "rustfmt failed with {status}");
-
-    // Write the output to `src/registry_gen.rs` (or stdout).
-    if cli.dry_run {
-        println!("{}", String::from_utf8(stdout)?);
-    } else {
-        let file = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-            .parent()
-            .expect("Failed to find root directory")
-            .join("src/registry_gen.rs");
-        if fs::read(&file).map_or(true, |old| old != stdout) {
-            fs::write(&file, stdout)?;
-        }
-    }
-
-    Ok(())
-}
--- a/ruff_dev/src/generate_cli_help.rs
+++ b/ruff_dev/src/generate_cli_help.rs
@@ -28,7 +28,7 @@ pub fn main(cli: &Cli) -> Result<()> {
        print!("{output}");
    } else {
        replace_readme_section(
-            &format!("```shell\n{output}\n```\n"),
+            &format!("```\n{output}\n```\n"),
            HELP_BEGIN_PRAGMA,
            HELP_END_PRAGMA,
        )?;
--- a/ruff_dev/src/generate_rules_table.rs
+++ b/ruff_dev/src/generate_rules_table.rs
@@ -3,7 +3,7 @@
 use anyhow::Result;
 use clap::Args;
 use itertools::Itertools;
-use ruff::registry::{CheckCategory, CheckCode};
+use ruff::registry::{RuleCode, RuleOrigin};
 use strum::IntoEnumIterator;

 use crate::utils::replace_readme_section;
@@ -25,24 +25,24 @@ pub fn main(cli: &Cli) -> Result<()> {
    // Generate the table string.
    let mut table_out = String::new();
    let mut toc_out = String::new();
-    for check_category in CheckCategory::iter() {
-        let codes_csv: String = check_category.codes().iter().map(AsRef::as_ref).join(", ");
-        table_out.push_str(&format!("### {} ({codes_csv})", check_category.title()));
+    for origin in RuleOrigin::iter() {
+        let codes_csv: String = origin.codes().iter().map(AsRef::as_ref).join(", ");
+        table_out.push_str(&format!("### {} ({codes_csv})", origin.title()));
        table_out.push('\n');
        table_out.push('\n');

        toc_out.push_str(&format!(
            "   1. [{} ({})](#{}-{})\n",
-            check_category.title(),
+            origin.title(),
            codes_csv,
-            check_category.title().to_lowercase().replace(' ', "-"),
+            origin.title().to_lowercase().replace(' ', "-"),
            codes_csv.to_lowercase().replace(',', "-").replace(' ', "")
        ));

-        if let Some((url, platform)) = check_category.url() {
+        if let Some((url, platform)) = origin.url() {
            table_out.push_str(&format!(
                "For more, see [{}]({}) on {}.",
-                check_category.title(),
+                origin.title(),
                url,
                platform
            ));
@@ -55,15 +55,15 @@ pub fn main(cli: &Cli) -> Result<()> {
        table_out.push_str("| ---- | ---- | ------- | --- |");
        table_out.push('\n');

-        for check_code in CheckCode::iter() {
-            if check_code.category() == check_category {
-                let check_kind = check_code.kind();
-                let fix_token = if check_kind.fixable() { "🛠" } else { "" };
+        for rule_code in RuleCode::iter() {
+            if rule_code.origin() == origin {
+                let kind = rule_code.kind();
+                let fix_token = if kind.fixable() { "🛠" } else { "" };
                table_out.push_str(&format!(
                    "| {} | {} | {} | {} |",
-                    check_kind.code().as_ref(),
-                    check_kind.as_ref(),
-                    check_kind.summary().replace('|', r"\|"),
+                    kind.code().as_ref(),
+                    kind.as_ref(),
+                    kind.summary().replace('|', r"\|"),
                    fix_token
                ));
                table_out.push('\n');
--- a/ruff_dev/src/lib.rs
+++ b/ruff_dev/src/lib.rs
@@ -10,9 +10,9 @@
    clippy::similar_names,
    clippy::too_many_lines
 )]
+#![forbid(unsafe_code)]

 pub mod generate_all;
-pub mod generate_check_code_prefix;
 pub mod generate_cli_help;
 pub mod generate_json_schema;
 pub mod generate_options;
--- a/ruff_dev/src/main.rs
+++ b/ruff_dev/src/main.rs
@@ -10,12 +10,13 @@
    clippy::similar_names,
    clippy::too_many_lines
 )]
+#![forbid(unsafe_code)]

 use anyhow::Result;
 use clap::{Parser, Subcommand};
 use ruff_dev::{
-    generate_all, generate_check_code_prefix, generate_cli_help, generate_json_schema,
-    generate_options, generate_rules_table, print_ast, print_cst, print_tokens, round_trip,
+    generate_all, generate_cli_help, generate_json_schema, generate_options, generate_rules_table,
+    print_ast, print_cst, print_tokens, round_trip,
 };

 #[derive(Parser)]
@@ -30,8 +31,6 @@ struct Cli {
 enum Commands {
    /// Run all code and documentation generation steps.
    GenerateAll(generate_all::Cli),
-    /// Generate the `CheckCodePrefix` enum.
-    GenerateCheckCodePrefix(generate_check_code_prefix::Cli),
    /// Generate JSON schema for the TOML configuration file.
    GenerateJSONSchema(generate_json_schema::Cli),
    /// Generate a Markdown-compatible table of supported lint rules.
@@ -54,7 +53,6 @@ fn main() -> Result<()> {
    let cli = Cli::parse();
    match &cli.command {
        Commands::GenerateAll(args) => generate_all::main(args)?,
-        Commands::GenerateCheckCodePrefix(args) => generate_check_code_prefix::main(args)?,
        Commands::GenerateJSONSchema(args) => generate_json_schema::main(args)?,
        Commands::GenerateRulesTable(args) => generate_rules_table::main(args)?,
        Commands::GenerateOptions(args) => generate_options::main(args)?,
--- a/ruff_dev/src/round_trip.rs
+++ b/ruff_dev/src/round_trip.rs
@@ -22,12 +22,8 @@ pub fn main(cli: &Cli) -> Result<()> {
    let python_ast = parser::parse_program(&contents, &cli.file.to_string_lossy())?;
    let locator = SourceCodeLocator::new(&contents);
    let stylist = SourceCodeStyleDetector::from_contents(&contents, &locator);
-    let mut generator = SourceCodeGenerator::new(
-        stylist.indentation(),
-        stylist.quote(),
-        stylist.line_ending(),
-    );
+    let mut generator: SourceCodeGenerator = (&stylist).into();
    generator.unparse_suite(&python_ast);
-    println!("{}", generator.generate()?);
+    println!("{}", generator.generate());
    Ok(())
 }
--- a/ruff_macros/Cargo.toml
+++ b/ruff_macros/Cargo.toml
@@ -1,12 +1,13 @@
 [package]
 name = "ruff_macros"
-version = "0.0.211"
+version = "0.0.216"
 edition = "2021"

 [lib]
 proc-macro = true

 [dependencies]
+once_cell = { version = "1.17.0" }
 proc-macro2 = { version = "1.0.47" }
 quote = { version = "1.0.21" }
 syn = { version = "1.0.103", features = ["derive", "parsing"] }
--- a/ruff_macros/src/config.rs
+++ b/ruff_macros/src/config.rs
@@ -0,0 +1,203 @@
+use quote::{quote, quote_spanned};
+use syn::parse::{Parse, ParseStream};
+use syn::spanned::Spanned;
+use syn::token::Comma;
+use syn::{
+    AngleBracketedGenericArguments, Attribute, Data, DataStruct, DeriveInput, Field, Fields, Lit,
+    LitStr, Path, PathArguments, PathSegment, Token, Type, TypePath,
+};
+
+pub fn derive_impl(input: DeriveInput) -> syn::Result<proc_macro2::TokenStream> {
+    let DeriveInput { ident, data, .. } = input;
+
+    match data {
+        Data::Struct(DataStruct {
+            fields: Fields::Named(fields),
+            ..
+        }) => {
+            let mut output = vec![];
+
+            for field in fields.named.iter() {
+                let docs: Vec<&Attribute> = field
+                    .attrs
+                    .iter()
+                    .filter(|attr| attr.path.is_ident("doc"))
+                    .collect();
+
+                if docs.is_empty() {
+                    return Err(syn::Error::new(
+                        field.span(),
+                        "Missing documentation for field",
+                    ));
+                }
+
+                if let Some(attr) = field.attrs.iter().find(|attr| attr.path.is_ident("option")) {
+                    output.push(handle_option(field, attr, docs)?);
+                };
+
+                if field
+                    .attrs
+                    .iter()
+                    .any(|attr| attr.path.is_ident("option_group"))
+                {
+                    output.push(handle_option_group(field)?);
+                };
+            }
+
+            Ok(quote! {
+              use crate::settings::options_base::{OptionEntry, OptionField, OptionGroup, ConfigurationOptions};
+
+              #[automatically_derived]
+              impl ConfigurationOptions for #ident {
+                  fn get_available_options() -> Vec<OptionEntry> {
+                      vec![#(#output),*]
+                  }
+              }
+            })
+        }
+        _ => Err(syn::Error::new(
+            ident.span(),
+            "Can only derive ConfigurationOptions from structs with named fields.",
+        )),
+    }
+}
+
+/// For a field with type `Option<Foobar>` where `Foobar` itself is a struct
+/// deriving `ConfigurationOptions`, create code that calls retrieves options
+/// from that group: `Foobar::get_available_options()`
+fn handle_option_group(field: &Field) -> syn::Result<proc_macro2::TokenStream> {
+    let ident = field
+        .ident
+        .as_ref()
+        .expect("Expected to handle named fields");
+
+    match &field.ty {
+        Type::Path(TypePath {
+            path: Path { segments, .. },
+            ..
+        }) => match segments.first() {
+            Some(PathSegment {
+                ident: type_ident,
+                arguments:
+                    PathArguments::AngleBracketed(AngleBracketedGenericArguments { args, .. }),
+                ..
+            }) if type_ident == "Option" => {
+                let path = &args[0];
+                let kebab_name = LitStr::new(&ident.to_string().replace('_', "-"), ident.span());
+
+                Ok(quote_spanned!(
+                    ident.span() => OptionEntry::Group(OptionGroup {
+                        name: #kebab_name,
+                        fields: #path::get_available_options(),
+                    })
+                ))
+            }
+            _ => Err(syn::Error::new(
+                ident.span(),
+                "Expected `Option<_>`  as type.",
+            )),
+        },
+        _ => Err(syn::Error::new(ident.span(), "Expected type.")),
+    }
+}
+
+/// Parse a `doc` attribute into it a string literal.
+fn parse_doc(doc: &Attribute) -> syn::Result<String> {
+    let doc = doc
+        .parse_meta()
+        .map_err(|e| syn::Error::new(doc.span(), e))?;
+
+    match doc {
+        syn::Meta::NameValue(syn::MetaNameValue {
+            lit: Lit::Str(lit_str),
+            ..
+        }) => Ok(lit_str.value()),
+        _ => Err(syn::Error::new(doc.span(), "Expected doc attribute.")),
+    }
+}
+
+/// Parse an `#[option(doc="...", default="...", value_type="...",
+/// example="...")]` attribute and return data in the form of an `OptionField`.
+fn handle_option(
+    field: &Field,
+    attr: &Attribute,
+    docs: Vec<&Attribute>,
+) -> syn::Result<proc_macro2::TokenStream> {
+    // Convert the list of `doc` attributes into a single string.
+    let doc = textwrap::dedent(
+        &docs
+            .into_iter()
+            .map(parse_doc)
+            .collect::<syn::Result<Vec<_>>>()?
+            .join("\n"),
+    )
+    .trim_matches('\n')
+    .to_string();
+
+    let ident = field
+        .ident
+        .as_ref()
+        .expect("Expected to handle named fields");
+
+    let FieldAttributes {
+        default,
+        value_type,
+        example,
+        ..
+    } = attr.parse_args::<FieldAttributes>()?;
+    let kebab_name = LitStr::new(&ident.to_string().replace('_', "-"), ident.span());
+
+    Ok(quote_spanned!(
+        ident.span() => OptionEntry::Field(OptionField {
+            name: #kebab_name,
+            doc: &#doc,
+            default: &#default,
+            value_type: &#value_type,
+            example: &#example,
+        })
+    ))
+}
+
+#[derive(Debug)]
+struct FieldAttributes {
+    default: String,
+    value_type: String,
+    example: String,
+}
+
+impl Parse for FieldAttributes {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let default = _parse_key_value(input, "default")?;
+        input.parse::<Comma>()?;
+        let value_type = _parse_key_value(input, "value_type")?;
+        input.parse::<Comma>()?;
+        let example = _parse_key_value(input, "example")?;
+        if !input.is_empty() {
+            input.parse::<Comma>()?;
+        }
+
+        Ok(FieldAttributes {
+            default,
+            value_type,
+            example: textwrap::dedent(&example).trim_matches('\n').to_string(),
+        })
+    }
+}
+
+fn _parse_key_value(input: ParseStream, name: &str) -> syn::Result<String> {
+    let ident: proc_macro2::Ident = input.parse()?;
+    if ident != name {
+        return Err(syn::Error::new(
+            ident.span(),
+            format!("Expected `{name}` name"),
+        ));
+    }
+
+    input.parse::<Token![=]>()?;
+    let value: Lit = input.parse()?;
+
+    match &value {
+        Lit::Str(v) => Ok(v.value()),
+        _ => Err(syn::Error::new(value.span(), "Expected literal string")),
+    }
+}
--- a/ruff_macros/src/lib.rs
+++ b/ruff_macros/src/lib.rs
@@ -10,216 +10,27 @@
    clippy::similar_names,
    clippy::too_many_lines
 )]
+#![forbid(unsafe_code)]

-use quote::{quote, quote_spanned};
-use syn::parse::{Parse, ParseStream};
-use syn::spanned::Spanned;
-use syn::token::Comma;
-use syn::{
-    parse_macro_input, AngleBracketedGenericArguments, Attribute, Data, DataStruct, DeriveInput,
-    Field, Fields, Lit, LitStr, Path, PathArguments, PathSegment, Token, Type, TypePath,
-};
+use syn::{parse_macro_input, DeriveInput};
+
+mod config;
+mod rule_code_prefix;

 #[proc_macro_derive(ConfigurationOptions, attributes(option, doc, option_group))]
-pub fn derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+pub fn derive_config(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input = parse_macro_input!(input as DeriveInput);

-    derive_impl(input)
+    config::derive_impl(input)
        .unwrap_or_else(syn::Error::into_compile_error)
        .into()
 }

-fn derive_impl(input: DeriveInput) -> syn::Result<proc_macro2::TokenStream> {
-    let DeriveInput { ident, data, .. } = input;
+#[proc_macro_derive(RuleCodePrefix)]
+pub fn derive_rule_code_prefix(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);

-    match data {
-        Data::Struct(DataStruct {
-            fields: Fields::Named(fields),
-            ..
-        }) => {
-            let mut output = vec![];
-
-            for field in fields.named.iter() {
-                let docs: Vec<&Attribute> = field
-                    .attrs
-                    .iter()
-                    .filter(|attr| attr.path.is_ident("doc"))
-                    .collect();
-
-                if docs.is_empty() {
-                    return Err(syn::Error::new(
-                        field.span(),
-                        "Missing documentation for field",
-                    ));
-                }
-
-                if let Some(attr) = field.attrs.iter().find(|attr| attr.path.is_ident("option")) {
-                    output.push(handle_option(field, attr, docs)?);
-                };
-
-                if field
-                    .attrs
-                    .iter()
-                    .any(|attr| attr.path.is_ident("option_group"))
-                {
-                    output.push(handle_option_group(field)?);
-                };
-            }
-
-            Ok(quote! {
-              use crate::settings::options_base::{OptionEntry, OptionField, OptionGroup, ConfigurationOptions};
-
-              #[automatically_derived]
-              impl ConfigurationOptions for #ident {
-                  fn get_available_options() -> Vec<OptionEntry> {
-                      vec![#(#output),*]
-                  }
-              }
-            })
-        }
-        _ => Err(syn::Error::new(
-            ident.span(),
-            "Can only derive ConfigurationOptions from structs with named fields.",
-        )),
-    }
-}
-
-/// For a field with type `Option<Foobar>` where `Foobar` itself is a struct
-/// deriving `ConfigurationOptions`, create code that calls retrieves options
-/// from that group: `Foobar::get_available_options()`
-fn handle_option_group(field: &Field) -> syn::Result<proc_macro2::TokenStream> {
-    let ident = field
-        .ident
-        .as_ref()
-        .expect("Expected to handle named fields");
-
-    match &field.ty {
-        Type::Path(TypePath {
-            path: Path { segments, .. },
-            ..
-        }) => match segments.first() {
-            Some(PathSegment {
-                ident: type_ident,
-                arguments:
-                    PathArguments::AngleBracketed(AngleBracketedGenericArguments { args, .. }),
-                ..
-            }) if type_ident == "Option" => {
-                let path = &args[0];
-                let kebab_name = LitStr::new(&ident.to_string().replace('_', "-"), ident.span());
-
-                Ok(quote_spanned!(
-                    ident.span() => OptionEntry::Group(OptionGroup {
-                        name: #kebab_name,
-                        fields: #path::get_available_options(),
-                    })
-                ))
-            }
-            _ => Err(syn::Error::new(
-                ident.span(),
-                "Expected `Option<_>`  as type.",
-            )),
-        },
-        _ => Err(syn::Error::new(ident.span(), "Expected type.")),
-    }
-}
-
-/// Parse a `doc` attribute into it a string literal.
-fn parse_doc(doc: &Attribute) -> syn::Result<String> {
-    let doc = doc
-        .parse_meta()
-        .map_err(|e| syn::Error::new(doc.span(), e))?;
-
-    match doc {
-        syn::Meta::NameValue(syn::MetaNameValue {
-            lit: Lit::Str(lit_str),
-            ..
-        }) => Ok(lit_str.value()),
-        _ => Err(syn::Error::new(doc.span(), "Expected doc attribute.")),
-    }
-}
-
-/// Parse an `#[option(doc="...", default="...", value_type="...",
-/// example="...")]` attribute and return data in the form of an `OptionField`.
-fn handle_option(
-    field: &Field,
-    attr: &Attribute,
-    docs: Vec<&Attribute>,
-) -> syn::Result<proc_macro2::TokenStream> {
-    // Convert the list of `doc` attributes into a single string.
-    let doc = textwrap::dedent(
-        &docs
-            .into_iter()
-            .map(parse_doc)
-            .collect::<syn::Result<Vec<_>>>()?
-            .join("\n"),
-    )
-    .trim_matches('\n')
-    .to_string();
-
-    let ident = field
-        .ident
-        .as_ref()
-        .expect("Expected to handle named fields");
-
-    let FieldAttributes {
-        default,
-        value_type,
-        example,
-        ..
-    } = attr.parse_args::<FieldAttributes>()?;
-    let kebab_name = LitStr::new(&ident.to_string().replace('_', "-"), ident.span());
-
-    Ok(quote_spanned!(
-        ident.span() => OptionEntry::Field(OptionField {
-            name: #kebab_name,
-            doc: &#doc,
-            default: &#default,
-            value_type: &#value_type,
-            example: &#example,
-        })
-    ))
-}
-
-#[derive(Debug)]
-struct FieldAttributes {
-    default: String,
-    value_type: String,
-    example: String,
-}
-
-impl Parse for FieldAttributes {
-    fn parse(input: ParseStream) -> syn::Result<Self> {
-        let default = _parse_key_value(input, "default")?;
-        input.parse::<Comma>()?;
-        let value_type = _parse_key_value(input, "value_type")?;
-        input.parse::<Comma>()?;
-        let example = _parse_key_value(input, "example")?;
-        if !input.is_empty() {
-            input.parse::<Comma>()?;
-        }
-
-        Ok(FieldAttributes {
-            default,
-            value_type,
-            example: textwrap::dedent(&example).trim_matches('\n').to_string(),
-        })
-    }
-}
-
-fn _parse_key_value(input: ParseStream, name: &str) -> syn::Result<String> {
-    let ident: proc_macro2::Ident = input.parse()?;
-    if ident != name {
-        return Err(syn::Error::new(
-            ident.span(),
-            format!("Expected `{name}` name"),
-        ));
-    }
-
-    input.parse::<Token![=]>()?;
-    let value: Lit = input.parse()?;
-
-    match &value {
-        Lit::Str(v) => Ok(v.value()),
-        _ => Err(syn::Error::new(value.span(), "Expected literal string")),
-    }
+    rule_code_prefix::derive_impl(input)
+        .unwrap_or_else(syn::Error::into_compile_error)
+        .into()
 }
--- a/ruff_macros/src/rule_code_prefix.rs
+++ b/ruff_macros/src/rule_code_prefix.rs
@@ -0,0 +1,287 @@
+use std::collections::{BTreeMap, BTreeSet, HashMap};
+
+use once_cell::sync::Lazy;
+use proc_macro2::Span;
+use quote::quote;
+use syn::punctuated::Punctuated;
+use syn::token::Comma;
+use syn::{DataEnum, DeriveInput, Ident, Variant};
+
+const ALL: &str = "ALL";
+
+/// A hash map from deprecated `RuleCodePrefix` to latest
+/// `RuleCodePrefix`.
+pub static PREFIX_REDIRECTS: Lazy<HashMap<&'static str, &'static str>> = Lazy::new(|| {
+    HashMap::from_iter([
+        // TODO(charlie): Remove by 2023-01-01.
+        ("U001", "UP001"),
+        ("U003", "UP003"),
+        ("U004", "UP004"),
+        ("U005", "UP005"),
+        ("U006", "UP006"),
+        ("U007", "UP007"),
+        ("U008", "UP008"),
+        ("U009", "UP009"),
+        ("U010", "UP010"),
+        ("U011", "UP011"),
+        ("U012", "UP012"),
+        ("U013", "UP013"),
+        ("U014", "UP014"),
+        ("U015", "UP015"),
+        ("U016", "UP016"),
+        ("U017", "UP017"),
+        ("U019", "UP019"),
+        // TODO(charlie): Remove by 2023-02-01.
+        ("I252", "TID252"),
+        ("M001", "RUF100"),
+        // TODO(charlie): Remove by 2023-02-01.
+        ("PDV002", "PD002"),
+        ("PDV003", "PD003"),
+        ("PDV004", "PD004"),
+        ("PDV007", "PD007"),
+        ("PDV008", "PD008"),
+        ("PDV009", "PD009"),
+        ("PDV010", "PD010"),
+        ("PDV011", "PD011"),
+        ("PDV012", "PD012"),
+        ("PDV013", "PD013"),
+        ("PDV015", "PD015"),
+        ("PDV901", "PD901"),
+        // TODO(charlie): Remove by 2023-02-01.
+        ("R501", "RET501"),
+        ("R502", "RET502"),
+        ("R503", "RET503"),
+        ("R504", "RET504"),
+        ("R505", "RET505"),
+        ("R506", "RET506"),
+        ("R507", "RET507"),
+        ("R508", "RET508"),
+        ("IC001", "ICN001"),
+        ("IC002", "ICN001"),
+        ("IC003", "ICN001"),
+        ("IC004", "ICN001"),
+        // TODO(charlie): Remove by 2023-01-01.
+        ("U", "UP"),
+        ("U0", "UP0"),
+        ("U00", "UP00"),
+        ("U01", "UP01"),
+        // TODO(charlie): Remove by 2023-02-01.
+        ("I2", "TID2"),
+        ("I25", "TID25"),
+        ("M", "RUF100"),
+        ("M0", "RUF100"),
+        // TODO(charlie): Remove by 2023-02-01.
+        ("PDV", "PD"),
+        ("PDV0", "PD0"),
+        ("PDV01", "PD01"),
+        ("PDV9", "PD9"),
+        ("PDV90", "PD90"),
+        // TODO(charlie): Remove by 2023-02-01.
+        ("R", "RET"),
+        ("R5", "RET5"),
+        ("R50", "RET50"),
+        // TODO(charlie): Remove by 2023-02-01.
+        ("IC", "ICN"),
+        ("IC0", "ICN0"),
+    ])
+});
+
+pub fn derive_impl(input: DeriveInput) -> syn::Result<proc_macro2::TokenStream> {
+    let DeriveInput { ident, data, .. } = input;
+    let syn::Data::Enum(DataEnum { variants, .. }) = data else {
+        return Err(syn::Error::new(
+            ident.span(),
+            "Can only derive `RuleCodePrefix` from enums.",
+        ));
+    };
+
+    let prefix_ident = Ident::new(&format!("{ident}Prefix"), ident.span());
+    let prefix = expand(&ident, &prefix_ident, &variants);
+    let expanded = quote! {
+        #[derive(PartialEq, Eq, PartialOrd, Ord)]
+        pub enum SuffixLength {
+            None,
+            Zero,
+            One,
+            Two,
+            Three,
+            Four,
+        }
+
+        #prefix
+    };
+    Ok(expanded)
+}
+
+fn expand(
+    ident: &Ident,
+    prefix_ident: &Ident,
+    variants: &Punctuated<Variant, Comma>,
+) -> proc_macro2::TokenStream {
+    // Build up a map from prefix to matching RuleCodes.
+    let mut prefix_to_codes: BTreeMap<Ident, BTreeSet<String>> = BTreeMap::default();
+    for variant in variants {
+        let span = variant.ident.span();
+        let code_str = variant.ident.to_string();
+        let code_prefix_len = code_str
+            .chars()
+            .take_while(|char| char.is_alphabetic())
+            .count();
+        let code_suffix_len = code_str.len() - code_prefix_len;
+        for i in 0..=code_suffix_len {
+            let prefix = code_str[..code_prefix_len + i].to_string();
+            prefix_to_codes
+                .entry(Ident::new(&prefix, span))
+                .or_default()
+                .insert(code_str.clone());
+        }
+        prefix_to_codes
+            .entry(Ident::new(ALL, span))
+            .or_default()
+            .insert(code_str.clone());
+    }
+
+    // Add any prefix aliases (e.g., "U" to "UP").
+    for (alias, rule_code) in PREFIX_REDIRECTS.iter() {
+        prefix_to_codes.insert(
+            Ident::new(alias, Span::call_site()),
+            prefix_to_codes
+                .get(&Ident::new(rule_code, Span::call_site()))
+                .unwrap_or_else(|| panic!("Unknown RuleCode: {alias:?}"))
+                .clone(),
+        );
+    }
+
+    let prefix_variants = prefix_to_codes.keys().map(|prefix| {
+        quote! {
+            #prefix
+        }
+    });
+
+    let prefix_impl = generate_impls(ident, prefix_ident, &prefix_to_codes);
+
+    let prefix_redirects = PREFIX_REDIRECTS.iter().map(|(alias, rule_code)| {
+        let code = Ident::new(rule_code, Span::call_site());
+        quote! {
+            (#alias, #prefix_ident::#code)
+        }
+    });
+
+    quote! {
+        #[derive(
+            ::strum_macros::EnumString,
+            ::strum_macros::AsRefStr,
+            Debug,
+            PartialEq,
+            Eq,
+            PartialOrd,
+            Ord,
+            Clone,
+            ::serde::Serialize,
+            ::serde::Deserialize,
+            ::schemars::JsonSchema,
+        )]
+        pub enum #prefix_ident {
+            #(#prefix_variants,)*
+        }
+
+        #prefix_impl
+
+        /// A hash map from deprecated `RuleCodePrefix` to latest `RuleCodePrefix`.
+        pub static PREFIX_REDIRECTS: ::once_cell::sync::Lazy<::rustc_hash::FxHashMap<&'static str, #prefix_ident>> = ::once_cell::sync::Lazy::new(|| {
+            ::rustc_hash::FxHashMap::from_iter([
+                #(#prefix_redirects),*
+            ])
+        });
+    }
+}
+
+fn generate_impls(
+    ident: &Ident,
+    prefix_ident: &Ident,
+    prefix_to_codes: &BTreeMap<Ident, BTreeSet<String>>,
+) -> proc_macro2::TokenStream {
+    let codes_match_arms = prefix_to_codes.iter().map(|(prefix, codes)| {
+        let codes = codes.iter().map(|code| {
+            let code = Ident::new(code, Span::call_site());
+            quote! {
+                #ident::#code
+            }
+        });
+        let prefix_str = prefix.to_string();
+        if let Some(target) = PREFIX_REDIRECTS.get(prefix_str.as_str()) {
+            quote! {
+                #prefix_ident::#prefix => {
+                    crate::warn_user_once!(
+                        "`{}` has been remapped to `{}`", #prefix_str, #target
+                    );
+                    vec![#(#codes),*]
+                }
+            }
+        } else {
+            quote! {
+                #prefix_ident::#prefix => vec![#(#codes),*],
+            }
+        }
+    });
+
+    let specificity_match_arms = prefix_to_codes.keys().map(|prefix| {
+        if *prefix == ALL {
+            quote! {
+                #prefix_ident::#prefix => SuffixLength::None,
+            }
+        } else {
+            let num_numeric = prefix
+                .to_string()
+                .chars()
+                .filter(|char| char.is_numeric())
+                .count();
+            let suffix_len = match num_numeric {
+                0 => quote! { SuffixLength::Zero },
+                1 => quote! { SuffixLength::One },
+                2 => quote! { SuffixLength::Two },
+                3 => quote! { SuffixLength::Three },
+                4 => quote! { SuffixLength::Four },
+                _ => panic!("Invalid prefix: {prefix}"),
+            };
+            quote! {
+                #prefix_ident::#prefix => #suffix_len,
+            }
+        }
+    });
+
+    let categories = prefix_to_codes.keys().map(|prefix| {
+        let prefix_str = prefix.to_string();
+        if prefix_str.chars().all(char::is_alphabetic)
+            && !PREFIX_REDIRECTS.contains_key(&prefix_str.as_str())
+        {
+            quote! {
+                #prefix_ident::#prefix,
+            }
+        } else {
+            quote! {}
+        }
+    });
+
+    quote! {
+        impl #prefix_ident {
+            pub fn codes(&self) -> Vec<#ident> {
+                use colored::Colorize;
+
+                #[allow(clippy::match_same_arms)]
+                match self {
+                    #(#codes_match_arms)*
+                }
+            }
+
+            pub fn specificity(&self) -> SuffixLength {
+                #[allow(clippy::match_same_arms)]
+                match self {
+                    #(#specificity_match_arms)*
+                }
+            }
+        }
+
+        pub const CATEGORIES: &[#prefix_ident] = &[#(#categories)*];
+    }
+}
--- a/scripts/add_check.py
+++ b/scripts/add_check.py
@@ -43,9 +43,9 @@ def main(*, name: str, code: str, plugin: str) -> None:

    with open(os.path.join(ROOT_DIR, f"src/{dir_name(plugin)}/mod.rs"), "w") as fp:
        for line in content.splitlines():
-            if line.strip() == "fn checks(check_code: CheckCode, path: &Path) -> Result<()> {":
-                indent = line.split("fn checks(check_code: CheckCode, path: &Path) -> Result<()> {")[0]
-                fp.write(f'{indent}#[test_case(CheckCode::{code}, Path::new("{code}.py"); "{code}")]')
+            if line.strip() == "fn rules(check_code: RuleCode, path: &Path) -> Result<()> {":
+                indent = line.split("fn rules(check_code: RuleCode, path: &Path) -> Result<()> {")[0]
+                fp.write(f'{indent}#[test_case(RuleCode::{code}, Path::new("{code}.py"); "{code}")]')
                fp.write("\n")

            fp.write(line)
@@ -73,39 +73,39 @@ pub fn {snake_case(name)}(checker: &mut Checker) {{}}

            if line.strip() == f"// {plugin}":
                if index == 0:
-                    # `CheckCode` definition
+                    # `RuleCode` definition
                    indent = line.split(f"// {plugin}")[0]
                    fp.write(f"{indent}{code},")
                    fp.write("\n")

                elif index == 1:
-                    # `CheckKind` definition
+                    # `DiagnosticKind` definition
                    indent = line.split(f"// {plugin}")[0]
                    fp.write(f"{indent}{name},")
                    fp.write("\n")

                elif index == 2:
-                    # `CheckCode#kind()`
+                    # `RuleCode#kind()`
                    indent = line.split(f"// {plugin}")[0]
-                    fp.write(f"{indent}CheckCode::{code} => CheckKind::{name},")
+                    fp.write(f"{indent}RuleCode::{code} => DiagnosticKind::{name},")
                    fp.write("\n")

                elif index == 3:
-                    # `CheckCode#category()`
+                    # `RuleCode#category()`
                    indent = line.split(f"// {plugin}")[0]
-                    fp.write(f"{indent}CheckCode::{code} => CheckCategory::{pascal_case(plugin)},")
+                    fp.write(f"{indent}RuleCode::{code} => CheckCategory::{pascal_case(plugin)},")
                    fp.write("\n")

                elif index == 4:
-                    # `CheckKind#code()`
+                    # `DiagnosticKind#code()`
                    indent = line.split(f"// {plugin}")[0]
-                    fp.write(f"{indent}CheckKind::{name} => &CheckCode::{code},")
+                    fp.write(f"{indent}DiagnosticKind::{name} => &RuleCode::{code},")
                    fp.write("\n")

                elif index == 5:
-                    # `CheckCode#body`
+                    # `RuleCode#body`
                    indent = line.split(f"// {plugin}")[0]
-                    fp.write(f'{indent}CheckKind::{name} => todo!("Write message body for {code}"),')
+                    fp.write(f'{indent}DiagnosticKind::{name} => todo!("Write message body for {code}"),')
                    fp.write("\n")

                index += 1
--- a/scripts/add_plugin.py
+++ b/scripts/add_plugin.py
@@ -31,10 +31,10 @@ def main(*, plugin: str, url: str) -> None:

    # Create the Rust module.
    os.makedirs(os.path.join(ROOT_DIR, f"src/{dir_name(plugin)}"), exist_ok=True)
-    with open(os.path.join(ROOT_DIR, f"src/{dir_name(plugin)}/plugins.rs"), "a"):
+    with open(os.path.join(ROOT_DIR, f"src/{dir_name(plugin)}/rules"), "a"):
        pass
-    with open(os.path.join(ROOT_DIR, f"src/{dir_name(plugin)}/mod.rs"), "w+") as fp:
-        fp.write("pub mod plugins;\n")
+    with open(os.path.join(ROOT_DIR, f"src/{dir_name(plugin)}/rules"), "w+") as fp:
+        fp.write("pub mod rules;\n")
        fp.write("\n")
        fp.write(
            """#[cfg(test)]
@@ -45,19 +45,19 @@ mod tests {
    use anyhow::Result;
    use test_case::test_case;

-    use crate::registry::CheckCode;
+    use crate::registry::RuleCode;
    use crate::linter::test_path;
    use crate::settings;

-    fn checks(check_code: CheckCode, path: &Path) -> Result<()> {
+    fn rules(check_code: RuleCode, path: &Path) -> Result<()> {
        let snapshot = format!("{}_{}", check_code.as_ref(), path.to_string_lossy());
-        let checks = test_path(
+        let diagnostics =test_path(
            Path::new("./resources/test/fixtures/%s")
                .join(path)
                .as_path(),
            &settings::Settings::for_rule(check_code),
        )?;
-        insta::assert_yaml_snapshot!(snapshot, checks);
+        insta::assert_yaml_snapshot!(snapshot, diagnostics);
        Ok(())
    }
 }
@@ -90,8 +90,8 @@ mod tests {
                fp.write(f'{indent}CheckCategory::{pascal_case(plugin)} => "{plugin}",')
                fp.write("\n")

-            elif line.strip() == "CheckCategory::Ruff => vec![CheckCodePrefix::RUF],":
-                indent = line.split("CheckCategory::Ruff => vec![CheckCodePrefix::RUF],")[0]
+            elif line.strip() == "CheckCategory::Ruff => vec![RuleCodePrefix::RUF],":
+                indent = line.split("CheckCategory::Ruff => vec![RuleCodePrefix::RUF],")[0]
                fp.write(
                    f"{indent}CheckCategory::{pascal_case(plugin)} => vec![\n"
                    f'{indent}    todo!("Fill-in prefix after generating codes")\n'
--- a/src/ast/branch_detection.rs
+++ b/src/ast/branch_detection.rs
@@ -52,8 +52,8 @@ fn common_ancestor<'a>(
 }

 /// Return the alternative branches for a given node.
-fn alternatives<'a>(node: &'a RefEquality<'a, Stmt>) -> Vec<Vec<RefEquality<'a, Stmt>>> {
-    match &node.0.node {
+fn alternatives<'a>(stmt: &'a RefEquality<'a, Stmt>) -> Vec<Vec<RefEquality<'a, Stmt>>> {
+    match &stmt.node {
        StmtKind::If { body, .. } => vec![body.iter().map(RefEquality).collect()],
        StmtKind::Try {
            body,
@@ -71,16 +71,16 @@ fn alternatives<'a>(node: &'a RefEquality<'a, Stmt>) -> Vec<Vec<RefEquality<'a,
    }
 }

-/// Return `true` if `node` is a descendent of any of the nodes in `ancestors`.
+/// Return `true` if `stmt` is a descendent of any of the nodes in `ancestors`.
 fn descendant_of<'a>(
-    node: &RefEquality<'a, Stmt>,
+    stmt: &RefEquality<'a, Stmt>,
    ancestors: &[RefEquality<'a, Stmt>],
    stop: &RefEquality<'a, Stmt>,
    depths: &FxHashMap<RefEquality<'a, Stmt>, usize>,
    child_to_parent: &FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
 ) -> bool {
    ancestors.iter().any(|ancestor| {
-        common_ancestor(node, ancestor, Some(stop), depths, child_to_parent).is_some()
+        common_ancestor(stmt, ancestor, Some(stop), depths, child_to_parent).is_some()
    })
 }

--- a/src/ast/comparable.rs
+++ b/src/ast/comparable.rs
@@ -0,0 +1,524 @@
+//! An equivalent object hierarchy to the `Expr` hierarchy, but with the ability
+//! to compare expressions for equality (via `Eq` and `Hash`).
+
+use num_bigint::BigInt;
+use rustpython_ast::{
+    Arg, Arguments, Boolop, Cmpop, Comprehension, Constant, Expr, ExprContext, ExprKind, Keyword,
+    Operator, Unaryop,
+};
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ComparableExprContext {
+    Load,
+    Store,
+    Del,
+}
+
+impl From<&ExprContext> for ComparableExprContext {
+    fn from(ctx: &ExprContext) -> Self {
+        match ctx {
+            ExprContext::Load => Self::Load,
+            ExprContext::Store => Self::Store,
+            ExprContext::Del => Self::Del,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ComparableBoolop {
+    And,
+    Or,
+}
+
+impl From<&Boolop> for ComparableBoolop {
+    fn from(op: &Boolop) -> Self {
+        match op {
+            Boolop::And => Self::And,
+            Boolop::Or => Self::Or,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ComparableOperator {
+    Add,
+    Sub,
+    Mult,
+    MatMult,
+    Div,
+    Mod,
+    Pow,
+    LShift,
+    RShift,
+    BitOr,
+    BitXor,
+    BitAnd,
+    FloorDiv,
+}
+
+impl From<&Operator> for ComparableOperator {
+    fn from(op: &Operator) -> Self {
+        match op {
+            Operator::Add => Self::Add,
+            Operator::Sub => Self::Sub,
+            Operator::Mult => Self::Mult,
+            Operator::MatMult => Self::MatMult,
+            Operator::Div => Self::Div,
+            Operator::Mod => Self::Mod,
+            Operator::Pow => Self::Pow,
+            Operator::LShift => Self::LShift,
+            Operator::RShift => Self::RShift,
+            Operator::BitOr => Self::BitOr,
+            Operator::BitXor => Self::BitXor,
+            Operator::BitAnd => Self::BitAnd,
+            Operator::FloorDiv => Self::FloorDiv,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ComparableUnaryop {
+    Invert,
+    Not,
+    UAdd,
+    USub,
+}
+
+impl From<&Unaryop> for ComparableUnaryop {
+    fn from(op: &Unaryop) -> Self {
+        match op {
+            Unaryop::Invert => Self::Invert,
+            Unaryop::Not => Self::Not,
+            Unaryop::UAdd => Self::UAdd,
+            Unaryop::USub => Self::USub,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ComparableCmpop {
+    Eq,
+    NotEq,
+    Lt,
+    LtE,
+    Gt,
+    GtE,
+    Is,
+    IsNot,
+    In,
+    NotIn,
+}
+
+impl From<&Cmpop> for ComparableCmpop {
+    fn from(op: &Cmpop) -> Self {
+        match op {
+            Cmpop::Eq => Self::Eq,
+            Cmpop::NotEq => Self::NotEq,
+            Cmpop::Lt => Self::Lt,
+            Cmpop::LtE => Self::LtE,
+            Cmpop::Gt => Self::Gt,
+            Cmpop::GtE => Self::GtE,
+            Cmpop::Is => Self::Is,
+            Cmpop::IsNot => Self::IsNot,
+            Cmpop::In => Self::In,
+            Cmpop::NotIn => Self::NotIn,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ComparableConstant<'a> {
+    None,
+    Bool(&'a bool),
+    Str(&'a str),
+    Bytes(&'a [u8]),
+    Int(&'a BigInt),
+    Tuple(Vec<ComparableConstant<'a>>),
+    Float(u64),
+    Complex { real: u64, imag: u64 },
+    Ellipsis,
+}
+
+impl<'a> From<&'a Constant> for ComparableConstant<'a> {
+    fn from(constant: &'a Constant) -> Self {
+        match constant {
+            Constant::None => Self::None,
+            Constant::Bool(value) => Self::Bool(value),
+            Constant::Str(value) => Self::Str(value),
+            Constant::Bytes(value) => Self::Bytes(value),
+            Constant::Int(value) => Self::Int(value),
+            Constant::Tuple(value) => {
+                Self::Tuple(value.iter().map(std::convert::Into::into).collect())
+            }
+            Constant::Float(value) => Self::Float(value.to_bits()),
+            Constant::Complex { real, imag } => Self::Complex {
+                real: real.to_bits(),
+                imag: imag.to_bits(),
+            },
+            Constant::Ellipsis => Self::Ellipsis,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub struct ComparableArguments<'a> {
+    pub posonlyargs: Vec<ComparableArg<'a>>,
+    pub args: Vec<ComparableArg<'a>>,
+    pub vararg: Option<ComparableArg<'a>>,
+    pub kwonlyargs: Vec<ComparableArg<'a>>,
+    pub kw_defaults: Vec<ComparableExpr<'a>>,
+    pub kwarg: Option<ComparableArg<'a>>,
+    pub defaults: Vec<ComparableExpr<'a>>,
+}
+
+impl<'a> From<&'a Arguments> for ComparableArguments<'a> {
+    fn from(arguments: &'a Arguments) -> Self {
+        Self {
+            posonlyargs: arguments
+                .posonlyargs
+                .iter()
+                .map(std::convert::Into::into)
+                .collect(),
+            args: arguments
+                .args
+                .iter()
+                .map(std::convert::Into::into)
+                .collect(),
+            vararg: arguments.vararg.as_ref().map(std::convert::Into::into),
+            kwonlyargs: arguments
+                .kwonlyargs
+                .iter()
+                .map(std::convert::Into::into)
+                .collect(),
+            kw_defaults: arguments
+                .kw_defaults
+                .iter()
+                .map(std::convert::Into::into)
+                .collect(),
+            kwarg: arguments.vararg.as_ref().map(std::convert::Into::into),
+            defaults: arguments
+                .defaults
+                .iter()
+                .map(std::convert::Into::into)
+                .collect(),
+        }
+    }
+}
+
+impl<'a> From<&'a Box<Arg>> for ComparableArg<'a> {
+    fn from(arg: &'a Box<Arg>) -> Self {
+        (&**arg).into()
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub struct ComparableArg<'a> {
+    pub arg: &'a str,
+    pub annotation: Option<Box<ComparableExpr<'a>>>,
+    pub type_comment: Option<&'a str>,
+}
+
+impl<'a> From<&'a Arg> for ComparableArg<'a> {
+    fn from(arg: &'a Arg) -> Self {
+        Self {
+            arg: &arg.node.arg,
+            annotation: arg.node.annotation.as_ref().map(std::convert::Into::into),
+            type_comment: arg.node.type_comment.as_deref(),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub struct ComparableKeyword<'a> {
+    pub arg: Option<&'a str>,
+    pub value: ComparableExpr<'a>,
+}
+
+impl<'a> From<&'a Keyword> for ComparableKeyword<'a> {
+    fn from(keyword: &'a Keyword) -> Self {
+        Self {
+            arg: keyword.node.arg.as_deref(),
+            value: (&keyword.node.value).into(),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub struct ComparableComprehension<'a> {
+    pub target: ComparableExpr<'a>,
+    pub iter: ComparableExpr<'a>,
+    pub ifs: Vec<ComparableExpr<'a>>,
+    pub is_async: &'a usize,
+}
+
+impl<'a> From<&'a Comprehension> for ComparableComprehension<'a> {
+    fn from(comprehension: &'a Comprehension) -> Self {
+        Self {
+            target: (&comprehension.target).into(),
+            iter: (&comprehension.iter).into(),
+            ifs: comprehension
+                .ifs
+                .iter()
+                .map(std::convert::Into::into)
+                .collect(),
+            is_async: &comprehension.is_async,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ComparableExpr<'a> {
+    BoolOp {
+        op: ComparableBoolop,
+        values: Vec<ComparableExpr<'a>>,
+    },
+    NamedExpr {
+        target: Box<ComparableExpr<'a>>,
+        value: Box<ComparableExpr<'a>>,
+    },
+    BinOp {
+        left: Box<ComparableExpr<'a>>,
+        op: ComparableOperator,
+        right: Box<ComparableExpr<'a>>,
+    },
+    UnaryOp {
+        op: ComparableUnaryop,
+        operand: Box<ComparableExpr<'a>>,
+    },
+    Lambda {
+        args: ComparableArguments<'a>,
+        body: Box<ComparableExpr<'a>>,
+    },
+    IfExp {
+        test: Box<ComparableExpr<'a>>,
+        body: Box<ComparableExpr<'a>>,
+        orelse: Box<ComparableExpr<'a>>,
+    },
+    Dict {
+        keys: Vec<ComparableExpr<'a>>,
+        values: Vec<ComparableExpr<'a>>,
+    },
+    Set {
+        elts: Vec<ComparableExpr<'a>>,
+    },
+    ListComp {
+        elt: Box<ComparableExpr<'a>>,
+        generators: Vec<ComparableComprehension<'a>>,
+    },
+    SetComp {
+        elt: Box<ComparableExpr<'a>>,
+        generators: Vec<ComparableComprehension<'a>>,
+    },
+    DictComp {
+        key: Box<ComparableExpr<'a>>,
+        value: Box<ComparableExpr<'a>>,
+        generators: Vec<ComparableComprehension<'a>>,
+    },
+    GeneratorExp {
+        elt: Box<ComparableExpr<'a>>,
+        generators: Vec<ComparableComprehension<'a>>,
+    },
+    Await {
+        value: Box<ComparableExpr<'a>>,
+    },
+    Yield {
+        value: Option<Box<ComparableExpr<'a>>>,
+    },
+    YieldFrom {
+        value: Box<ComparableExpr<'a>>,
+    },
+    Compare {
+        left: Box<ComparableExpr<'a>>,
+        ops: Vec<ComparableCmpop>,
+        comparators: Vec<ComparableExpr<'a>>,
+    },
+    Call {
+        func: Box<ComparableExpr<'a>>,
+        args: Vec<ComparableExpr<'a>>,
+        keywords: Vec<ComparableKeyword<'a>>,
+    },
+    FormattedValue {
+        value: Box<ComparableExpr<'a>>,
+        conversion: &'a usize,
+        format_spec: Option<Box<ComparableExpr<'a>>>,
+    },
+    JoinedStr {
+        values: Vec<ComparableExpr<'a>>,
+    },
+    Constant {
+        value: ComparableConstant<'a>,
+        kind: Option<&'a str>,
+    },
+    Attribute {
+        value: Box<ComparableExpr<'a>>,
+        attr: &'a str,
+        ctx: ComparableExprContext,
+    },
+    Subscript {
+        value: Box<ComparableExpr<'a>>,
+        slice: Box<ComparableExpr<'a>>,
+        ctx: ComparableExprContext,
+    },
+    Starred {
+        value: Box<ComparableExpr<'a>>,
+        ctx: ComparableExprContext,
+    },
+    Name {
+        id: &'a str,
+        ctx: ComparableExprContext,
+    },
+    List {
+        elts: Vec<ComparableExpr<'a>>,
+        ctx: ComparableExprContext,
+    },
+    Tuple {
+        elts: Vec<ComparableExpr<'a>>,
+        ctx: ComparableExprContext,
+    },
+    Slice {
+        lower: Option<Box<ComparableExpr<'a>>>,
+        upper: Option<Box<ComparableExpr<'a>>>,
+        step: Option<Box<ComparableExpr<'a>>>,
+    },
+}
+
+impl<'a> From<&'a Box<Expr>> for Box<ComparableExpr<'a>> {
+    fn from(expr: &'a Box<Expr>) -> Self {
+        Box::new((&**expr).into())
+    }
+}
+
+impl<'a> From<&'a Expr> for ComparableExpr<'a> {
+    fn from(expr: &'a Expr) -> Self {
+        match &expr.node {
+            ExprKind::BoolOp { op, values } => Self::BoolOp {
+                op: op.into(),
+                values: values.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::NamedExpr { target, value } => Self::NamedExpr {
+                target: target.into(),
+                value: value.into(),
+            },
+            ExprKind::BinOp { left, op, right } => Self::BinOp {
+                left: left.into(),
+                op: op.into(),
+                right: right.into(),
+            },
+            ExprKind::UnaryOp { op, operand } => Self::UnaryOp {
+                op: op.into(),
+                operand: operand.into(),
+            },
+            ExprKind::Lambda { args, body } => Self::Lambda {
+                args: (&**args).into(),
+                body: body.into(),
+            },
+            ExprKind::IfExp { test, body, orelse } => Self::IfExp {
+                test: test.into(),
+                body: body.into(),
+                orelse: orelse.into(),
+            },
+            ExprKind::Dict { keys, values } => Self::Dict {
+                keys: keys.iter().map(std::convert::Into::into).collect(),
+                values: values.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::Set { elts } => Self::Set {
+                elts: elts.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::ListComp { elt, generators } => Self::ListComp {
+                elt: elt.into(),
+                generators: generators.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::SetComp { elt, generators } => Self::SetComp {
+                elt: elt.into(),
+                generators: generators.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::DictComp {
+                key,
+                value,
+                generators,
+            } => Self::DictComp {
+                key: key.into(),
+                value: value.into(),
+                generators: generators.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::GeneratorExp { elt, generators } => Self::GeneratorExp {
+                elt: elt.into(),
+                generators: generators.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::Await { value } => Self::Await {
+                value: value.into(),
+            },
+            ExprKind::Yield { value } => Self::Yield {
+                value: value.as_ref().map(std::convert::Into::into),
+            },
+            ExprKind::YieldFrom { value } => Self::YieldFrom {
+                value: value.into(),
+            },
+            ExprKind::Compare {
+                left,
+                ops,
+                comparators,
+            } => Self::Compare {
+                left: left.into(),
+                ops: ops.iter().map(std::convert::Into::into).collect(),
+                comparators: comparators.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::Call {
+                func,
+                args,
+                keywords,
+            } => Self::Call {
+                func: func.into(),
+                args: args.iter().map(std::convert::Into::into).collect(),
+                keywords: keywords.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::FormattedValue {
+                value,
+                conversion,
+                format_spec,
+            } => Self::FormattedValue {
+                value: value.into(),
+                conversion,
+                format_spec: format_spec.as_ref().map(std::convert::Into::into),
+            },
+            ExprKind::JoinedStr { values } => Self::JoinedStr {
+                values: values.iter().map(std::convert::Into::into).collect(),
+            },
+            ExprKind::Constant { value, kind } => Self::Constant {
+                value: value.into(),
+                kind: kind.as_ref().map(String::as_str),
+            },
+            ExprKind::Attribute { value, attr, ctx } => Self::Attribute {
+                value: value.into(),
+                attr,
+                ctx: ctx.into(),
+            },
+            ExprKind::Subscript { value, slice, ctx } => Self::Subscript {
+                value: value.into(),
+                slice: slice.into(),
+                ctx: ctx.into(),
+            },
+            ExprKind::Starred { value, ctx } => Self::Starred {
+                value: value.into(),
+                ctx: ctx.into(),
+            },
+            ExprKind::Name { id, ctx } => Self::Name {
+                id,
+                ctx: ctx.into(),
+            },
+            ExprKind::List { elts, ctx } => Self::List {
+                elts: elts.iter().map(std::convert::Into::into).collect(),
+                ctx: ctx.into(),
+            },
+            ExprKind::Tuple { elts, ctx } => Self::Tuple {
+                elts: elts.iter().map(std::convert::Into::into).collect(),
+                ctx: ctx.into(),
+            },
+            ExprKind::Slice { lower, upper, step } => Self::Slice {
+                lower: lower.as_ref().map(std::convert::Into::into),
+                upper: upper.as_ref().map(std::convert::Into::into),
+                step: step.as_ref().map(std::convert::Into::into),
+            },
+        }
+    }
+}
--- a/src/ast/helpers.rs
+++ b/src/ast/helpers.rs
@@ -11,7 +11,9 @@ use rustpython_parser::lexer;
 use rustpython_parser::lexer::Tok;
 use rustpython_parser::token::StringKind;

-use crate::ast::types::Range;
+use crate::ast::types::{Binding, BindingKind, Range};
+use crate::source_code_generator::SourceCodeGenerator;
+use crate::source_code_style::SourceCodeStyleDetector;
 use crate::SourceCodeLocator;

 /// Create an `Expr` with default location from an `ExprKind`.
@@ -24,6 +26,20 @@ pub fn create_stmt(node: StmtKind) -> Stmt {
    Stmt::new(Location::default(), Location::default(), node)
 }

+/// Generate source code from an `Expr`.
+pub fn unparse_expr(expr: &Expr, stylist: &SourceCodeStyleDetector) -> String {
+    let mut generator: SourceCodeGenerator = stylist.into();
+    generator.unparse_expr(expr, 0);
+    generator.generate()
+}
+
+/// Generate source code from an `Stmt`.
+pub fn unparse_stmt(stmt: &Stmt, stylist: &SourceCodeStyleDetector) -> String {
+    let mut generator: SourceCodeGenerator = stylist.into();
+    generator.unparse_stmt(stmt);
+    generator.generate()
+}
+
 fn collect_call_path_inner<'a>(expr: &'a Expr, parts: &mut Vec<&'a str>) {
    match &expr.node {
        ExprKind::Call { func, .. } => {
@@ -213,23 +229,6 @@ pub fn is_constant_non_singleton(expr: &Expr) -> bool {
    is_constant(expr) && !is_singleton(expr)
 }

-/// Return `true` if an `Expr` is not a reference to a variable (or something
-/// that could resolve to a variable, like a function call).
-pub fn is_non_variable(expr: &Expr) -> bool {
-    matches!(
-        expr.node,
-        ExprKind::Constant { .. }
-            | ExprKind::Tuple { .. }
-            | ExprKind::List { .. }
-            | ExprKind::Set { .. }
-            | ExprKind::Dict { .. }
-            | ExprKind::SetComp { .. }
-            | ExprKind::ListComp { .. }
-            | ExprKind::DictComp { .. }
-            | ExprKind::GeneratorExp { .. }
-    )
-}
-
 /// Return the `Keyword` with the given name, if it's present in the list of
 /// `Keyword` arguments.
 pub fn find_keyword<'a>(keywords: &'a [Keyword], keyword_name: &str) -> Option<&'a Keyword> {
@@ -316,7 +315,7 @@ pub fn is_super_call_with_arguments(func: &Expr, args: &[Expr]) -> bool {
 }

 /// Format the module name for a relative import.
-pub fn format_import_from(level: Option<&usize>, module: Option<&String>) -> String {
+pub fn format_import_from(level: Option<&usize>, module: Option<&str>) -> String {
    let mut module_name = String::with_capacity(16);
    if let Some(level) = level {
        for _ in 0..*level {
@@ -407,6 +406,22 @@ pub fn identifier_range(stmt: &Stmt, locator: &SourceCodeLocator) -> Range {
    Range::from_located(stmt)
 }

+/// Like `identifier_range`, but accepts a `Binding`.
+pub fn binding_range(binding: &Binding, locator: &SourceCodeLocator) -> Range {
+    if matches!(
+        binding.kind,
+        BindingKind::ClassDefinition | BindingKind::FunctionDefinition
+    ) {
+        if let Some(source) = &binding.source {
+            identifier_range(source, locator)
+        } else {
+            binding.range
+        }
+    } else {
+        binding.range
+    }
+}
+
 // Return the ranges of `Name` tokens within a specified node.
 pub fn find_names<T>(located: &Located<T>, locator: &SourceCodeLocator) -> Vec<Range> {
    let contents = locator.slice_source_code_range(&Range::from_located(located));
@@ -555,7 +570,7 @@ pub fn preceded_by_continuation(stmt: &Stmt, locator: &SourceCodeLocator) -> boo
            Location::new(stmt.location.row(), 0),
        );
        let line = locator.slice_source_code_range(&range);
-        if line.trim().ends_with('\\') {
+        if line.trim_end().ends_with('\\') {
            return true;
        }
    }
@@ -582,7 +597,7 @@ pub struct SimpleCallArgs<'a> {
 }

 impl<'a> SimpleCallArgs<'a> {
-    pub fn new(args: &'a Vec<Expr>, keywords: &'a Vec<Keyword>) -> Self {
+    pub fn new(args: &'a [Expr], keywords: &'a [Keyword]) -> Self {
        let mut result = SimpleCallArgs::default();

        for arg in args {
--- a/src/ast/mod.rs
+++ b/src/ast/mod.rs
@@ -1,5 +1,6 @@
 pub mod branch_detection;
 pub mod cast;
+pub mod comparable;
 pub mod function_type;
 pub mod helpers;
 pub mod operations;
--- a/src/ast/operations.rs
+++ b/src/ast/operations.rs
@@ -120,7 +120,7 @@ pub fn on_conditional_branch<'a>(parents: &mut impl Iterator<Item = &'a Stmt>) -
 }

 /// Check if a node is in a nested block.
-pub fn in_nested_block<'a>(parents: &mut impl Iterator<Item = &'a Stmt>) -> bool {
+pub fn in_nested_block<'a>(mut parents: impl Iterator<Item = &'a Stmt>) -> bool {
    parents.any(|parent| {
        matches!(
            parent.node,
@@ -212,7 +212,7 @@ pub fn is_unpacking_assignment(parent: &Stmt, child: &Expr) -> bool {
                ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
            );
            // In `(a, b) = coords = (1, 2)`, `(a, b)` and `coords` are the targets, and
-            // `(a, b`) is a tuple. (We use "tuple" as a placeholder for any
+            // `(a, b)` is a tuple. (We use "tuple" as a placeholder for any
            // unpackable expression.)
            let targets_are_tuples = targets.iter().all(|item| {
                matches!(
--- a/src/ast/types.rs
+++ b/src/ast/types.rs
@@ -1,3 +1,4 @@
+use std::ops::Deref;
 use std::sync::atomic::{AtomicUsize, Ordering};

 use rustc_hash::FxHashMap;
@@ -215,3 +216,23 @@ impl<'a, 'b, T> PartialEq<RefEquality<'b, T>> for RefEquality<'a, T> {
 }

 impl<'a, T> Eq for RefEquality<'a, T> {}
+
+impl<'a, T> Deref for RefEquality<'a, T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        self.0
+    }
+}
+
+impl<'a> From<&RefEquality<'a, Stmt>> for &'a Stmt {
+    fn from(r: &RefEquality<'a, Stmt>) -> Self {
+        r.0
+    }
+}
+
+impl<'a> From<&RefEquality<'a, Expr>> for &'a Expr {
+    fn from(r: &RefEquality<'a, Expr>) -> Self {
+        r.0
+    }
+}
--- a/src/autofix/fixer.rs
+++ b/src/autofix/fixer.rs
@@ -7,7 +7,7 @@ use rustpython_parser::ast::Location;

 use crate::ast::types::Range;
 use crate::autofix::Fix;
-use crate::registry::Check;
+use crate::registry::Diagnostic;
 use crate::source_code_locator::SourceCodeLocator;

 #[derive(Debug, Copy, Clone, Hash)]
@@ -30,15 +30,15 @@ impl From<bool> for Mode {

 /// Auto-fix errors in a file, and write the fixed source code to disk.
 pub fn fix_file<'a>(
-    checks: &'a [Check],
+    diagnostics: &'a [Diagnostic],
    locator: &'a SourceCodeLocator<'a>,
 ) -> Option<(Cow<'a, str>, usize)> {
-    if checks.iter().all(|check| check.fix.is_none()) {
+    if diagnostics.iter().all(|check| check.fix.is_none()) {
        return None;
    }

    Some(apply_fixes(
-        checks.iter().filter_map(|check| check.fix.as_ref()),
+        diagnostics.iter().filter_map(|check| check.fix.as_ref()),
        locator,
    ))
 }
--- a/src/cache.rs
+++ b/src/cache.rs
@@ -1,6 +1,5 @@
 use std::collections::hash_map::DefaultHasher;
 use std::fs;
-use std::fs::{create_dir_all, File, Metadata};
 use std::hash::{Hash, Hasher};
 use std::io::Write;
 use std::path::{Path, PathBuf};
@@ -8,16 +7,15 @@ use std::path::{Path, PathBuf};
 use anyhow::Result;
 use filetime::FileTime;
 use log::error;
-use once_cell::sync::Lazy;
 use path_absolutize::Absolutize;
 use serde::{Deserialize, Serialize};

 use crate::message::Message;
 use crate::settings::{flags, Settings};

+pub const CACHE_DIR_NAME: &str = ".ruff_cache";
+
 const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
-static CACHE_DIR: Lazy<Option<String>> = Lazy::new(|| std::env::var("RUFF_CACHE_DIR").ok());
-pub const DEFAULT_CACHE_DIR_NAME: &str = ".ruff_cache";

 #[derive(Serialize, Deserialize)]
 struct CacheMetadata {
@@ -39,9 +37,7 @@ struct CheckResult {
 /// Return the cache directory for a given project root. Defers to the
 /// `RUFF_CACHE_DIR` environment variable, if set.
 pub fn cache_dir(project_root: &Path) -> PathBuf {
-    CACHE_DIR
-        .as_ref()
-        .map_or_else(|| project_root.join(DEFAULT_CACHE_DIR_NAME), PathBuf::from)
+    project_root.join(CACHE_DIR_NAME)
 }

 fn content_dir() -> &'static Path {
@@ -60,7 +56,7 @@ fn cache_key<P: AsRef<Path>>(path: P, settings: &Settings, autofix: flags::Autof
 /// Initialize the cache at the specified `Path`.
 pub fn init(path: &Path) -> Result<()> {
    // Create the cache directories.
-    create_dir_all(path.join(content_dir()))?;
+    fs::create_dir_all(path.join(content_dir()))?;

    // Add the CACHEDIR.TAG.
    if !cachedir::is_tagged(path)? {
@@ -70,7 +66,7 @@ pub fn init(path: &Path) -> Result<()> {
    // Add the .gitignore.
    let gitignore_path = path.join(".gitignore");
    if !gitignore_path.exists() {
-        let mut file = File::create(gitignore_path)?;
+        let mut file = fs::File::create(gitignore_path)?;
        file.write_all(b"*")?;
    }

@@ -91,7 +87,7 @@ fn read_sync(cache_dir: &Path, key: u64) -> Result<Vec<u8>, std::io::Error> {
 /// Get a value from the cache.
 pub fn get<P: AsRef<Path>>(
    path: P,
-    metadata: &Metadata,
+    metadata: &fs::Metadata,
    settings: &Settings,
    autofix: flags::Autofix,
 ) -> Option<Vec<Message>> {
@@ -115,7 +111,7 @@ pub fn get<P: AsRef<Path>>(
 /// Set a value in the cache.
 pub fn set<P: AsRef<Path>>(
    path: P,
-    metadata: &Metadata,
+    metadata: &fs::Metadata,
    settings: &Settings,
    autofix: flags::Autofix,
    messages: &[Message],
--- a/src/checkers/ast.rs
+++ b/src/checkers/ast.rs
--- a/src/checkers/imports.rs
+++ b/src/checkers/imports.rs
@@ -8,7 +8,7 @@ use crate::ast::visitor::Visitor;
 use crate::directives::IsortDirectives;
 use crate::isort;
 use crate::isort::track::ImportTracker;
-use crate::registry::Check;
+use crate::registry::Diagnostic;
 use crate::settings::{flags, Settings};
 use crate::source_code_locator::SourceCodeLocator;
 use crate::source_code_style::SourceCodeStyleDetector;
@@ -20,18 +20,18 @@ fn check_import_blocks(
    stylist: &SourceCodeStyleDetector,
    autofix: flags::Autofix,
    package: Option<&Path>,
-) -> Vec<Check> {
-    let mut checks = vec![];
+) -> Vec<Diagnostic> {
+    let mut diagnostics = vec![];
    for block in tracker.into_iter() {
        if !block.imports.is_empty() {
-            if let Some(check) =
-                isort::plugins::check_imports(&block, locator, settings, stylist, autofix, package)
+            if let Some(diagnostic) =
+                isort::rules::check_imports(&block, locator, settings, stylist, autofix, package)
            {
-                checks.push(check);
+                diagnostics.push(diagnostic);
            }
        }
    }
-    checks
+    diagnostics
 }

 #[allow(clippy::too_many_arguments)]
@@ -44,7 +44,7 @@ pub fn check_imports(
    autofix: flags::Autofix,
    path: &Path,
    package: Option<&Path>,
-) -> Vec<Check> {
+) -> Vec<Diagnostic> {
    let mut tracker = ImportTracker::new(locator, directives, path);
    for stmt in python_ast {
        tracker.visit_stmt(stmt);
--- a/src/checkers/lines.rs
+++ b/src/checkers/lines.rs
@@ -1,9 +1,9 @@
 //! Lint rules based on checking raw physical lines.

-use crate::pycodestyle::checks::{line_too_long, no_newline_at_end_of_file};
-use crate::pygrep_hooks::plugins::{blanket_noqa, blanket_type_ignore};
-use crate::pyupgrade::checks::unnecessary_coding_comment;
-use crate::registry::{Check, CheckCode};
+use crate::pycodestyle::rules::{line_too_long, no_newline_at_end_of_file};
+use crate::pygrep_hooks::rules::{blanket_noqa, blanket_type_ignore};
+use crate::pyupgrade::rules::unnecessary_coding_comment;
+use crate::registry::{Diagnostic, RuleCode};
 use crate::settings::{flags, Settings};

 pub fn check_lines(
@@ -11,14 +11,14 @@ pub fn check_lines(
    commented_lines: &[usize],
    settings: &Settings,
    autofix: flags::Autofix,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
+) -> Vec<Diagnostic> {
+    let mut diagnostics: Vec<Diagnostic> = vec![];

-    let enforce_unnecessary_coding_comment = settings.enabled.contains(&CheckCode::UP009);
-    let enforce_line_too_long = settings.enabled.contains(&CheckCode::E501);
-    let enforce_no_newline_at_end_of_file = settings.enabled.contains(&CheckCode::W292);
-    let enforce_blanket_type_ignore = settings.enabled.contains(&CheckCode::PGH003);
-    let enforce_blanket_noqa = settings.enabled.contains(&CheckCode::PGH004);
+    let enforce_unnecessary_coding_comment = settings.enabled.contains(&RuleCode::UP009);
+    let enforce_line_too_long = settings.enabled.contains(&RuleCode::E501);
+    let enforce_no_newline_at_end_of_file = settings.enabled.contains(&RuleCode::W292);
+    let enforce_blanket_type_ignore = settings.enabled.contains(&RuleCode::PGH003);
+    let enforce_blanket_noqa = settings.enabled.contains(&RuleCode::PGH004);

    let mut commented_lines_iter = commented_lines.iter().peekable();
    for (index, line) in contents.lines().enumerate() {
@@ -28,59 +28,59 @@ pub fn check_lines(
        {
            if enforce_unnecessary_coding_comment {
                if index < 2 {
-                    if let Some(check) = unnecessary_coding_comment(
+                    if let Some(diagnostic) = unnecessary_coding_comment(
                        index,
                        line,
                        matches!(autofix, flags::Autofix::Enabled)
-                            && settings.fixable.contains(&CheckCode::UP009),
+                            && settings.fixable.contains(&RuleCode::UP009),
                    ) {
-                        checks.push(check);
+                        diagnostics.push(diagnostic);
                    }
                }
            }

            if enforce_blanket_type_ignore {
                if commented_lines.contains(&(index + 1)) {
-                    if let Some(check) = blanket_type_ignore(index, line) {
-                        checks.push(check);
+                    if let Some(diagnostic) = blanket_type_ignore(index, line) {
+                        diagnostics.push(diagnostic);
                    }
                }
            }

            if enforce_blanket_noqa {
                if commented_lines.contains(&(index + 1)) {
-                    if let Some(check) = blanket_noqa(index, line) {
-                        checks.push(check);
+                    if let Some(diagnostic) = blanket_noqa(index, line) {
+                        diagnostics.push(diagnostic);
                    }
                }
            }
        }

        if enforce_line_too_long {
-            if let Some(check) = line_too_long(index, line, settings) {
-                checks.push(check);
+            if let Some(diagnostic) = line_too_long(index, line, settings) {
+                diagnostics.push(diagnostic);
            }
        }
    }

    if enforce_no_newline_at_end_of_file {
-        if let Some(check) = no_newline_at_end_of_file(
+        if let Some(diagnostic) = no_newline_at_end_of_file(
            contents,
            matches!(autofix, flags::Autofix::Enabled)
-                && settings.fixable.contains(&CheckCode::W292),
+                && settings.fixable.contains(&RuleCode::W292),
        ) {
-            checks.push(check);
+            diagnostics.push(diagnostic);
        }
    }

-    checks
+    diagnostics
 }

 #[cfg(test)]
 mod tests {

    use super::check_lines;
-    use crate::registry::CheckCode;
+    use crate::registry::RuleCode;
    use crate::settings::{flags, Settings};

    #[test]
@@ -92,7 +92,7 @@ mod tests {
                &[],
                &Settings {
                    line_length,
-                    ..Settings::for_rule(CheckCode::E501)
+                    ..Settings::for_rule(RuleCode::E501)
                },
                flags::Autofix::Enabled,
            )
--- a/src/checkers/noqa.rs
+++ b/src/checkers/noqa.rs
@@ -7,13 +7,14 @@ use rustpython_parser::ast::Location;

 use crate::ast::types::Range;
 use crate::autofix::Fix;
-use crate::noqa;
 use crate::noqa::{is_file_exempt, Directive};
-use crate::registry::{Check, CheckCode, CheckKind, UnusedCodes, CODE_REDIRECTS};
+use crate::registry::{Diagnostic, DiagnosticKind, RuleCode, CODE_REDIRECTS};
 use crate::settings::{flags, Settings};
+use crate::violations::UnusedCodes;
+use crate::{noqa, violations};

 pub fn check_noqa(
-    checks: &mut Vec<Check>,
+    diagnostics: &mut Vec<Diagnostic>,
    contents: &str,
    commented_lines: &[usize],
    noqa_line_for: &IntMap<usize, usize>,
@@ -23,13 +24,13 @@ pub fn check_noqa(
    let mut noqa_directives: IntMap<usize, (Directive, Vec<&str>)> = IntMap::default();
    let mut ignored = vec![];

-    let enforce_noqa = settings.enabled.contains(&CheckCode::RUF100);
+    let enforce_noqa = settings.enabled.contains(&RuleCode::RUF100);

    let lines: Vec<&str> = contents.lines().collect();
    for lineno in commented_lines {
        // If we hit an exemption for the entire file, bail.
        if is_file_exempt(lines[lineno - 1]) {
-            checks.drain(..);
+            diagnostics.drain(..);
            return;
        }

@@ -40,14 +41,14 @@ pub fn check_noqa(
        }
    }

-    // Remove any ignored checks.
-    for (index, check) in checks.iter().enumerate() {
-        if check.kind == CheckKind::BlanketNOQA {
+    // Remove any ignored diagnostics.
+    for (index, diagnostic) in diagnostics.iter().enumerate() {
+        if matches!(diagnostic.kind, DiagnosticKind::BlanketNOQA(..)) {
            continue;
        }

        // Is the check ignored by a `noqa` directive on the parent line?
-        if let Some(parent_lineno) = check.parent.map(|location| location.row()) {
+        if let Some(parent_lineno) = diagnostic.parent.map(|location| location.row()) {
            let noqa_lineno = noqa_line_for.get(&parent_lineno).unwrap_or(&parent_lineno);
            if commented_lines.contains(noqa_lineno) {
                let noqa = noqa_directives.entry(noqa_lineno - 1).or_insert_with(|| {
@@ -55,13 +56,13 @@ pub fn check_noqa(
                });
                match noqa {
                    (Directive::All(..), matches) => {
-                        matches.push(check.kind.code().as_ref());
+                        matches.push(diagnostic.kind.code().as_ref());
                        ignored.push(index);
                        continue;
                    }
                    (Directive::Codes(.., codes), matches) => {
-                        if noqa::includes(check.kind.code(), codes) {
-                            matches.push(check.kind.code().as_ref());
+                        if noqa::includes(diagnostic.kind.code(), codes) {
+                            matches.push(diagnostic.kind.code().as_ref());
                            ignored.push(index);
                            continue;
                        }
@@ -71,21 +72,23 @@ pub fn check_noqa(
            }
        }

-        // Is the check ignored by a `noqa` directive on the same line?
-        let check_lineno = check.location.row();
-        let noqa_lineno = noqa_line_for.get(&check_lineno).unwrap_or(&check_lineno);
+        // Is the diagnostic ignored by a `noqa` directive on the same line?
+        let diagnostic_lineno = diagnostic.location.row();
+        let noqa_lineno = noqa_line_for
+            .get(&diagnostic_lineno)
+            .unwrap_or(&diagnostic_lineno);
        if commented_lines.contains(noqa_lineno) {
            let noqa = noqa_directives
                .entry(noqa_lineno - 1)
                .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno - 1]), vec![]));
            match noqa {
                (Directive::All(..), matches) => {
-                    matches.push(check.kind.code().as_ref());
+                    matches.push(diagnostic.kind.code().as_ref());
                    ignored.push(index);
                }
                (Directive::Codes(.., codes), matches) => {
-                    if noqa::includes(check.kind.code(), codes) {
-                        matches.push(check.kind.code().as_ref());
+                    if noqa::includes(diagnostic.kind.code(), codes) {
+                        matches.push(diagnostic.kind.code().as_ref());
                        ignored.push(index);
                    }
                }
@@ -100,19 +103,19 @@ pub fn check_noqa(
            match directive {
                Directive::All(spaces, start, end) => {
                    if matches.is_empty() {
-                        let mut check = Check::new(
-                            CheckKind::UnusedNOQA(None),
+                        let mut diagnostic = Diagnostic::new(
+                            violations::UnusedNOQA(None),
                            Range::new(Location::new(row + 1, start), Location::new(row + 1, end)),
                        );
                        if matches!(autofix, flags::Autofix::Enabled)
-                            && settings.fixable.contains(check.kind.code())
+                            && settings.fixable.contains(diagnostic.kind.code())
                        {
-                            check.amend(Fix::deletion(
+                            diagnostic.amend(Fix::deletion(
                                Location::new(row + 1, start - spaces),
                                Location::new(row + 1, lines[row].chars().count()),
                            ));
                        }
-                        checks.push(check);
+                        diagnostics.push(diagnostic);
                    }
                }
                Directive::Codes(spaces, start, end, codes) => {
@@ -123,7 +126,7 @@ pub fn check_noqa(
                    let mut self_ignore = false;
                    for code in codes {
                        let code = CODE_REDIRECTS.get(code).map_or(code, AsRef::as_ref);
-                        if code == CheckCode::RUF100.as_ref() {
+                        if code == RuleCode::RUF100.as_ref() {
                            self_ignore = true;
                            break;
                        }
@@ -131,8 +134,8 @@ pub fn check_noqa(
                        if matches.contains(&code) || settings.external.contains(code) {
                            valid_codes.push(code);
                        } else {
-                            if let Ok(check_code) = CheckCode::from_str(code) {
-                                if settings.enabled.contains(&check_code) {
+                            if let Ok(rule_code) = RuleCode::from_str(code) {
+                                if settings.enabled.contains(&rule_code) {
                                    unmatched_codes.push(code);
                                } else {
                                    disabled_codes.push(code);
@@ -151,8 +154,8 @@ pub fn check_noqa(
                        && unknown_codes.is_empty()
                        && unmatched_codes.is_empty())
                    {
-                        let mut check = Check::new(
-                            CheckKind::UnusedNOQA(Some(UnusedCodes {
+                        let mut diagnostic = Diagnostic::new(
+                            violations::UnusedNOQA(Some(UnusedCodes {
                                disabled: disabled_codes
                                    .iter()
                                    .map(|code| (*code).to_string())
@@ -169,22 +172,22 @@ pub fn check_noqa(
                            Range::new(Location::new(row + 1, start), Location::new(row + 1, end)),
                        );
                        if matches!(autofix, flags::Autofix::Enabled)
-                            && settings.fixable.contains(check.kind.code())
+                            && settings.fixable.contains(diagnostic.kind.code())
                        {
                            if valid_codes.is_empty() {
-                                check.amend(Fix::deletion(
+                                diagnostic.amend(Fix::deletion(
                                    Location::new(row + 1, start - spaces),
                                    Location::new(row + 1, lines[row].chars().count()),
                                ));
                            } else {
-                                check.amend(Fix::replacement(
+                                diagnostic.amend(Fix::replacement(
                                    format!("# noqa: {}", valid_codes.join(", ")),
                                    Location::new(row + 1, start),
                                    Location::new(row + 1, lines[row].chars().count()),
                                ));
                            }
                        }
-                        checks.push(check);
+                        diagnostics.push(diagnostic);
                    }
                }
                Directive::None => {}
@@ -194,6 +197,6 @@ pub fn check_noqa(

    ignored.sort_unstable();
    for index in ignored.iter().rev() {
-        checks.swap_remove(*index);
+        diagnostics.swap_remove(*index);
    }
 }
--- a/src/checkers/tokens.rs
+++ b/src/checkers/tokens.rs
@@ -3,8 +3,8 @@
 use rustpython_parser::lexer::{LexResult, Tok};

 use crate::lex::docstring_detection::StateMachine;
-use crate::registry::{Check, CheckCode};
-use crate::ruff::checks::Context;
+use crate::registry::{Diagnostic, RuleCode};
+use crate::ruff::rules::Context;
 use crate::settings::flags;
 use crate::source_code_locator::SourceCodeLocator;
 use crate::{eradicate, flake8_implicit_str_concat, flake8_quotes, pycodestyle, ruff, Settings};
@@ -14,20 +14,20 @@ pub fn check_tokens(
    tokens: &[LexResult],
    settings: &Settings,
    autofix: flags::Autofix,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
+) -> Vec<Diagnostic> {
+    let mut diagnostics: Vec<Diagnostic> = vec![];

-    let enforce_ambiguous_unicode_character = settings.enabled.contains(&CheckCode::RUF001)
-        || settings.enabled.contains(&CheckCode::RUF002)
-        || settings.enabled.contains(&CheckCode::RUF003);
-    let enforce_quotes = settings.enabled.contains(&CheckCode::Q000)
-        || settings.enabled.contains(&CheckCode::Q001)
-        || settings.enabled.contains(&CheckCode::Q002)
-        || settings.enabled.contains(&CheckCode::Q003);
-    let enforce_commented_out_code = settings.enabled.contains(&CheckCode::ERA001);
-    let enforce_invalid_escape_sequence = settings.enabled.contains(&CheckCode::W605);
-    let enforce_implicit_string_concatenation = settings.enabled.contains(&CheckCode::ISC001)
-        || settings.enabled.contains(&CheckCode::ISC002);
+    let enforce_ambiguous_unicode_character = settings.enabled.contains(&RuleCode::RUF001)
+        || settings.enabled.contains(&RuleCode::RUF002)
+        || settings.enabled.contains(&RuleCode::RUF003);
+    let enforce_quotes = settings.enabled.contains(&RuleCode::Q000)
+        || settings.enabled.contains(&RuleCode::Q001)
+        || settings.enabled.contains(&RuleCode::Q002)
+        || settings.enabled.contains(&RuleCode::Q003);
+    let enforce_commented_out_code = settings.enabled.contains(&RuleCode::ERA001);
+    let enforce_invalid_escape_sequence = settings.enabled.contains(&RuleCode::W605);
+    let enforce_implicit_string_concatenation = settings.enabled.contains(&RuleCode::ISC001)
+        || settings.enabled.contains(&RuleCode::ISC002);

    let mut state_machine = StateMachine::default();
    for &(start, ref tok, end) in tokens.iter().flatten() {
@@ -39,8 +39,8 @@ pub fn check_tokens(

        // RUF001, RUF002, RUF003
        if enforce_ambiguous_unicode_character {
-            if matches!(tok, Tok::String { .. } | Tok::Comment) {
-                checks.extend(ruff::checks::ambiguous_unicode_character(
+            if matches!(tok, Tok::String { .. } | Tok::Comment(_)) {
+                diagnostics.extend(ruff::rules::ambiguous_unicode_character(
                    locator,
                    start,
                    end,
@@ -62,15 +62,15 @@ pub fn check_tokens(
        // flake8-quotes
        if enforce_quotes {
            if matches!(tok, Tok::String { .. }) {
-                if let Some(check) = flake8_quotes::checks::quotes(
+                if let Some(diagnostic) = flake8_quotes::rules::quotes(
                    locator,
                    start,
                    end,
                    is_docstring,
                    &settings.flake8_quotes,
                ) {
-                    if settings.enabled.contains(check.kind.code()) {
-                        checks.push(check);
+                    if settings.enabled.contains(diagnostic.kind.code()) {
+                        diagnostics.push(diagnostic);
                    }
                }
            }
@@ -78,11 +78,11 @@ pub fn check_tokens(

        // eradicate
        if enforce_commented_out_code {
-            if matches!(tok, Tok::Comment) {
-                if let Some(check) =
-                    eradicate::checks::commented_out_code(locator, start, end, settings, autofix)
+            if matches!(tok, Tok::Comment(_)) {
+                if let Some(diagnostic) =
+                    eradicate::rules::commented_out_code(locator, start, end, settings, autofix)
                {
-                    checks.push(check);
+                    diagnostics.push(diagnostic);
                }
            }
        }
@@ -90,12 +90,12 @@ pub fn check_tokens(
        // W605
        if enforce_invalid_escape_sequence {
            if matches!(tok, Tok::String { .. }) {
-                checks.extend(pycodestyle::checks::invalid_escape_sequence(
+                diagnostics.extend(pycodestyle::rules::invalid_escape_sequence(
                    locator,
                    start,
                    end,
                    matches!(autofix, flags::Autofix::Enabled)
-                        && settings.fixable.contains(&CheckCode::W605),
+                        && settings.fixable.contains(&RuleCode::W605),
                ));
            }
        }
@@ -103,12 +103,12 @@ pub fn check_tokens(

    // ISC001, ISC002
    if enforce_implicit_string_concatenation {
-        checks.extend(
-            flake8_implicit_str_concat::checks::implicit(tokens, locator)
+        diagnostics.extend(
+            flake8_implicit_str_concat::rules::implicit(tokens, locator)
                .into_iter()
-                .filter(|check| settings.enabled.contains(check.kind.code())),
+                .filter(|diagnostic| settings.enabled.contains(diagnostic.kind.code())),
        );
    }

-    checks
+    diagnostics
 }
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -6,8 +6,7 @@ use rustc_hash::FxHashMap;

 use crate::fs;
 use crate::logging::LogLevel;
-use crate::registry::CheckCode;
-use crate::registry_gen::CheckCodePrefix;
+use crate::registry::{RuleCode, RuleCodePrefix};
 use crate::settings::types::{
    FilePattern, PatternPrefixPair, PerFileIgnore, PythonVersion, SerializationFormat,
 };
@@ -21,7 +20,7 @@ pub struct Cli {
    pub files: Vec<PathBuf>,
    /// Path to the `pyproject.toml` or `ruff.toml` file to use for
    /// configuration.
-    #[arg(long)]
+    #[arg(long, conflicts_with = "isolated")]
    pub config: Option<PathBuf>,
    /// Enable verbose logging.
    #[arg(short, long, group = "verbosity")]
@@ -57,21 +56,24 @@ pub struct Cli {
    /// Disable cache reads.
    #[arg(short, long)]
    pub no_cache: bool,
-    /// Comma-separated list of error codes to enable (or ALL, to enable all
-    /// checks).
+    /// Ignore all configuration files.
+    #[arg(long, conflicts_with = "config")]
+    pub isolated: bool,
+    /// Comma-separated list of rule codes to enable (or ALL, to enable all
+    /// rules).
    #[arg(long, value_delimiter = ',')]
-    pub select: Option<Vec<CheckCodePrefix>>,
+    pub select: Option<Vec<RuleCodePrefix>>,
    /// Like --select, but adds additional error codes on top of the selected
    /// ones.
    #[arg(long, value_delimiter = ',')]
-    pub extend_select: Option<Vec<CheckCodePrefix>>,
+    pub extend_select: Option<Vec<RuleCodePrefix>>,
    /// Comma-separated list of error codes to disable.
    #[arg(long, value_delimiter = ',')]
-    pub ignore: Option<Vec<CheckCodePrefix>>,
+    pub ignore: Option<Vec<RuleCodePrefix>>,
    /// Like --ignore, but adds additional error codes on top of the ignored
    /// ones.
    #[arg(long, value_delimiter = ',')]
-    pub extend_ignore: Option<Vec<CheckCodePrefix>>,
+    pub extend_ignore: Option<Vec<RuleCodePrefix>>,
    /// List of paths, used to exclude files and/or directories from checks.
    #[arg(long, value_delimiter = ',')]
    pub exclude: Option<Vec<FilePattern>>,
@@ -82,22 +84,22 @@ pub struct Cli {
    /// List of error codes to treat as eligible for autofix. Only applicable
    /// when autofix itself is enabled (e.g., via `--fix`).
    #[arg(long, value_delimiter = ',')]
-    pub fixable: Option<Vec<CheckCodePrefix>>,
+    pub fixable: Option<Vec<RuleCodePrefix>>,
    /// List of error codes to treat as ineligible for autofix. Only applicable
    /// when autofix itself is enabled (e.g., via `--fix`).
    #[arg(long, value_delimiter = ',')]
-    pub unfixable: Option<Vec<CheckCodePrefix>>,
+    pub unfixable: Option<Vec<RuleCodePrefix>>,
    /// List of mappings from file pattern to code to exclude
    #[arg(long, value_delimiter = ',')]
    pub per_file_ignores: Option<Vec<PatternPrefixPair>>,
    /// Output serialization format for error messages.
-    #[arg(long, value_enum)]
+    #[arg(long, value_enum, env = "RUFF_FORMAT")]
    pub format: Option<SerializationFormat>,
    /// The name of the file when passing it through stdin.
    #[arg(long)]
    pub stdin_filename: Option<PathBuf>,
    /// Path to the cache directory.
-    #[arg(long)]
+    #[arg(long, env = "RUFF_CACHE_DIR")]
    pub cache_dir: Option<PathBuf>,
    /// Show violations with source code.
    #[arg(long, overrides_with("no_show_source"))]
@@ -177,7 +179,7 @@ pub struct Cli {
        conflicts_with = "stdin_filename",
        conflicts_with = "watch",
    )]
-    pub explain: Option<CheckCode>,
+    pub explain: Option<RuleCode>,
    /// Generate shell completion
    #[arg(
        long,
@@ -241,6 +243,7 @@ impl Cli {
                explain: self.explain,
                files: self.files,
                generate_shell_completion: self.generate_shell_completion,
+                isolated: self.isolated,
                no_cache: self.no_cache,
                quiet: self.quiet,
                show_files: self.show_files,
@@ -299,9 +302,10 @@ pub struct Arguments {
    pub config: Option<PathBuf>,
    pub diff: bool,
    pub exit_zero: bool,
-    pub explain: Option<CheckCode>,
+    pub explain: Option<RuleCode>,
    pub files: Vec<PathBuf>,
    pub generate_shell_completion: Option<clap_complete_command::Shell>,
+    pub isolated: bool,
    pub no_cache: bool,
    pub quiet: bool,
    pub show_files: bool,
@@ -319,18 +323,18 @@ pub struct Overrides {
    pub dummy_variable_rgx: Option<Regex>,
    pub exclude: Option<Vec<FilePattern>>,
    pub extend_exclude: Option<Vec<FilePattern>>,
-    pub extend_ignore: Option<Vec<CheckCodePrefix>>,
-    pub extend_select: Option<Vec<CheckCodePrefix>>,
-    pub fixable: Option<Vec<CheckCodePrefix>>,
-    pub ignore: Option<Vec<CheckCodePrefix>>,
+    pub extend_ignore: Option<Vec<RuleCodePrefix>>,
+    pub extend_select: Option<Vec<RuleCodePrefix>>,
+    pub fixable: Option<Vec<RuleCodePrefix>>,
+    pub ignore: Option<Vec<RuleCodePrefix>>,
    pub line_length: Option<usize>,
    pub max_complexity: Option<usize>,
    pub per_file_ignores: Option<Vec<PatternPrefixPair>>,
    pub respect_gitignore: Option<bool>,
-    pub select: Option<Vec<CheckCodePrefix>>,
+    pub select: Option<Vec<RuleCodePrefix>>,
    pub show_source: Option<bool>,
    pub target_version: Option<PythonVersion>,
-    pub unfixable: Option<Vec<CheckCodePrefix>>,
+    pub unfixable: Option<Vec<RuleCodePrefix>>,
    // TODO(charlie): Captured in pyproject.toml as a default, but not part of `Settings`.
    pub cache_dir: Option<PathBuf>,
    pub fix: Option<bool>,
@@ -355,7 +359,7 @@ pub fn extract_log_level(cli: &Arguments) -> LogLevel {

 /// Convert a list of `PatternPrefixPair` structs to `PerFileIgnore`.
 pub fn collect_per_file_ignores(pairs: Vec<PatternPrefixPair>) -> Vec<PerFileIgnore> {
-    let mut per_file_ignores: FxHashMap<String, Vec<CheckCodePrefix>> = FxHashMap::default();
+    let mut per_file_ignores: FxHashMap<String, Vec<RuleCodePrefix>> = FxHashMap::default();
    for pair in pairs {
        per_file_ignores
            .entry(pair.pattern)
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -16,17 +16,17 @@ use serde::Serialize;
 use walkdir::WalkDir;

 use crate::autofix::fixer;
-use crate::cache::DEFAULT_CACHE_DIR_NAME;
+use crate::cache::CACHE_DIR_NAME;
 use crate::cli::Overrides;
 use crate::iterators::par_iter;
 use crate::linter::{add_noqa_to_path, lint_path, lint_stdin, Diagnostics};
 use crate::logging::LogLevel;
 use crate::message::Message;
-use crate::registry::{CheckCode, CheckKind};
+use crate::registry::RuleCode;
 use crate::resolver::{FileDiscovery, PyprojectDiscovery};
 use crate::settings::flags;
 use crate::settings::types::SerializationFormat;
-use crate::{cache, fs, one_time_warning, packages, resolver};
+use crate::{cache, fs, packages, resolver, violations, warn_user_once};

 /// Run the linter over a collection of files.
 pub fn run(
@@ -45,12 +45,7 @@ pub fn run(
    debug!("Identified files to lint in: {:?}", duration);

    if paths.is_empty() {
-        one_time_warning!(
-            "{}{} {}",
-            "warning".yellow().bold(),
-            ":".bold(),
-            "No Python files found under the given path(s)".bold()
-        );
+        warn_user_once!("No Python files found under the given path(s)");
        return Ok(Diagnostics::default());
    }

@@ -117,9 +112,9 @@ pub fn run(
            .unwrap_or_else(|(path, message)| {
                if let Some(path) = &path {
                    let settings = resolver.resolve(path, pyproject_strategy);
-                    if settings.enabled.contains(&CheckCode::E902) {
+                    if settings.enabled.contains(&RuleCode::E902) {
                        Diagnostics::new(vec![Message {
-                            kind: CheckKind::IOError(message),
+                            kind: violations::IOError(message).into(),
                            location: Location::default(),
                            end_location: Location::default(),
                            fix: None,
@@ -196,12 +191,7 @@ pub fn add_noqa(
    debug!("Identified files to lint in: {:?}", duration);

    if paths.is_empty() {
-        one_time_warning!(
-            "{}{} {}",
-            "warning".yellow().bold(),
-            ":".bold(),
-            "No Python files found under the given path(s)".bold()
-        );
+        warn_user_once!("No Python files found under the given path(s)");
        return Ok(0);
    }

@@ -271,12 +261,7 @@ pub fn show_files(
        resolver::python_files_in_path(files, pyproject_strategy, file_strategy, overrides)?;

    if paths.is_empty() {
-        one_time_warning!(
-            "{}{} {}",
-            "warning".yellow().bold(),
-            ":".bold(),
-            "No Python files found under the given path(s)".bold()
-        );
+        warn_user_once!("No Python files found under the given path(s)");
        return Ok(());
    }

@@ -298,18 +283,18 @@ pub fn show_files(
 #[derive(Serialize)]
 struct Explanation<'a> {
    code: &'a str,
-    category: &'a str,
+    origin: &'a str,
    summary: &'a str,
 }

-/// Explain a `CheckCode` to the user.
-pub fn explain(code: &CheckCode, format: &SerializationFormat) -> Result<()> {
+/// Explain a `RuleCode` to the user.
+pub fn explain(code: &RuleCode, format: &SerializationFormat) -> Result<()> {
    match format {
        SerializationFormat::Text | SerializationFormat::Grouped => {
            println!(
                "{} ({}): {}",
                code.as_ref(),
-                code.category().title(),
+                code.origin().title(),
                code.kind().summary()
            );
        }
@@ -318,7 +303,7 @@ pub fn explain(code: &CheckCode, format: &SerializationFormat) -> Result<()> {
                "{}",
                serde_json::to_string_pretty(&Explanation {
                    code: code.as_ref(),
-                    category: code.category().title(),
+                    origin: code.origin().title(),
                    summary: &code.kind().summary(),
                })?
            );
@@ -340,10 +325,10 @@ pub fn explain(code: &CheckCode, format: &SerializationFormat) -> Result<()> {
 pub fn clean(level: &LogLevel) -> Result<()> {
    for entry in WalkDir::new(&*path_dedot::CWD)
        .into_iter()
-        .filter_map(std::result::Result::ok)
+        .filter_map(Result::ok)
        .filter(|entry| entry.file_type().is_dir())
    {
-        let cache = entry.path().join(DEFAULT_CACHE_DIR_NAME);
+        let cache = entry.path().join(CACHE_DIR_NAME);
        if cache.is_dir() {
            if level >= &LogLevel::Default {
                eprintln!("Removing cache at: {}", fs::relativize_path(&cache).bold());
--- a/src/directives.rs
+++ b/src/directives.rs
@@ -5,9 +5,8 @@ use nohash_hasher::{IntMap, IntSet};
 use rustpython_ast::Location;
 use rustpython_parser::lexer::{LexResult, Tok};

-use crate::ast::types::Range;
 use crate::registry::LintSource;
-use crate::{Settings, SourceCodeLocator};
+use crate::Settings;

 bitflags! {
    pub struct Flags: u32 {
@@ -21,7 +20,7 @@ impl Flags {
        if settings
            .enabled
            .iter()
-            .any(|check_code| matches!(check_code.lint_source(), LintSource::Imports))
+            .any(|rule_code| matches!(rule_code.lint_source(), LintSource::Imports))
        {
            Flags::NOQA | Flags::ISORT
        } else {
@@ -42,11 +41,7 @@ pub struct Directives {
    pub isort: IsortDirectives,
 }

-pub fn extract_directives(
-    lxr: &[LexResult],
-    locator: &SourceCodeLocator,
-    flags: Flags,
-) -> Directives {
+pub fn extract_directives(lxr: &[LexResult], flags: Flags) -> Directives {
    Directives {
        commented_lines: extract_commented_lines(lxr),
        noqa_line_for: if flags.contains(Flags::NOQA) {
@@ -55,7 +50,7 @@ pub fn extract_directives(
            IntMap::default()
        },
        isort: if flags.contains(Flags::ISORT) {
-            extract_isort_directives(lxr, locator)
+            extract_isort_directives(lxr)
        } else {
            IsortDirectives::default()
        },
@@ -65,7 +60,7 @@ pub fn extract_directives(
 pub fn extract_commented_lines(lxr: &[LexResult]) -> Vec<usize> {
    let mut commented_lines = Vec::new();
    for (start, tok, ..) in lxr.iter().flatten() {
-        if matches!(tok, Tok::Comment) {
+        if matches!(tok, Tok::Comment(_)) {
            commented_lines.push(start.row());
        }
    }
@@ -91,7 +86,7 @@ pub fn extract_noqa_line_for(lxr: &[LexResult]) -> IntMap<usize, usize> {
 }

 /// Extract a set of lines over which to disable isort.
-pub fn extract_isort_directives(lxr: &[LexResult], locator: &SourceCodeLocator) -> IsortDirectives {
+pub fn extract_isort_directives(lxr: &[LexResult]) -> IsortDirectives {
    let mut exclusions: IntSet<usize> = IntSet::default();
    let mut splits: Vec<usize> = Vec::default();
    let mut skip_file: bool = false;
@@ -105,16 +100,17 @@ pub fn extract_isort_directives(lxr: &[LexResult], locator: &SourceCodeLocator)
            continue;
        }

-        if !matches!(tok, Tok::Comment) {
+        let Tok::Comment(comment_text) = tok else {
            continue;
-        }
-
-        // TODO(charlie): Modify RustPython to include the comment text in the token.
-        let comment_text = locator.slice_source_code_range(&Range::new(start, end));
+        };

+        // `isort` allows for `# isort: skip` and `# isort: skip_file` to include or
+        // omit a space after the colon. The remaining action comments are
+        // required to include the space, and must appear on their own lines.
+        let comment_text = comment_text.trim_end();
        if comment_text == "# isort: split" {
            splits.push(start.row());
-        } else if comment_text == "# isort: skip_file" {
+        } else if comment_text == "# isort: skip_file" || comment_text == "# isort:skip_file" {
            skip_file = true;
        } else if off.is_some() {
            if comment_text == "# isort: on" {
@@ -126,13 +122,14 @@ pub fn extract_isort_directives(lxr: &[LexResult], locator: &SourceCodeLocator)
                off = None;
            }
        } else {
-            if comment_text.contains("isort: skip") {
+            if comment_text.contains("isort: skip") || comment_text.contains("isort:skip") {
                exclusions.insert(start.row());
            } else if comment_text == "# isort: off" {
                off = Some(start);
            }
        }
    }
+
    if skip_file {
        // Enforce `isort: skip_file`.
        if let Some(end) = last {
@@ -158,7 +155,6 @@ mod tests {
    use rustpython_parser::lexer::LexResult;

    use crate::directives::{extract_isort_directives, extract_noqa_line_for};
-    use crate::SourceCodeLocator;

    #[test]
    fn noqa_extraction() {
@@ -246,11 +242,7 @@ z = x + 1",
 y = 2
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
-        assert_eq!(
-            extract_isort_directives(&lxr, &locator).exclusions,
-            IntSet::default()
-        );
+        assert_eq!(extract_isort_directives(&lxr).exclusions, IntSet::default());

        let contents = "# isort: off
 x = 1
@@ -258,9 +250,8 @@ y = 2
 # isort: on
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
        assert_eq!(
-            extract_isort_directives(&lxr, &locator).exclusions,
+            extract_isort_directives(&lxr).exclusions,
            IntSet::from_iter([2, 3, 4])
        );

@@ -272,9 +263,8 @@ y = 2
 z = x + 1
 # isort: on";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
        assert_eq!(
-            extract_isort_directives(&lxr, &locator).exclusions,
+            extract_isort_directives(&lxr).exclusions,
            IntSet::from_iter([2, 3, 4, 5])
        );

@@ -283,9 +273,8 @@ x = 1
 y = 2
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
        assert_eq!(
-            extract_isort_directives(&lxr, &locator).exclusions,
+            extract_isort_directives(&lxr).exclusions,
            IntSet::from_iter([2, 3, 4])
        );

@@ -294,9 +283,8 @@ x = 1
 y = 2
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
        assert_eq!(
-            extract_isort_directives(&lxr, &locator).exclusions,
+            extract_isort_directives(&lxr).exclusions,
            IntSet::from_iter([1, 2, 3, 4])
        );

@@ -307,9 +295,8 @@ y = 2
 # isort: skip_file
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
        assert_eq!(
-            extract_isort_directives(&lxr, &locator).exclusions,
+            extract_isort_directives(&lxr).exclusions,
            IntSet::from_iter([1, 2, 3, 4, 5, 6])
        );
    }
@@ -320,25 +307,19 @@ z = x + 1";
 y = 2
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
-        assert_eq!(
-            extract_isort_directives(&lxr, &locator).splits,
-            Vec::<usize>::new()
-        );
+        assert_eq!(extract_isort_directives(&lxr).splits, Vec::<usize>::new());

        let contents = "x = 1
 y = 2
 # isort: split
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
-        assert_eq!(extract_isort_directives(&lxr, &locator).splits, vec![3]);
+        assert_eq!(extract_isort_directives(&lxr).splits, vec![3]);

        let contents = "x = 1
 y = 2  # isort: split
 z = x + 1";
        let lxr: Vec<LexResult> = lexer::make_tokenizer(contents).collect();
-        let locator = SourceCodeLocator::new(contents);
-        assert_eq!(extract_isort_directives(&lxr, &locator).splits, vec![2]);
+        assert_eq!(extract_isort_directives(&lxr).splits, vec![2]);
    }
 }
--- a/src/eradicate/mod.rs
+++ b/src/eradicate/mod.rs
@@ -1,5 +1,5 @@
-pub mod checks;
 pub mod detection;
+pub mod rules;

 #[cfg(test)]
 mod tests {
@@ -10,19 +10,19 @@ mod tests {
    use test_case::test_case;

    use crate::linter::test_path;
-    use crate::registry::CheckCode;
+    use crate::registry::RuleCode;
    use crate::settings;

-    #[test_case(CheckCode::ERA001, Path::new("ERA001.py"); "ERA001")]
-    fn checks(check_code: CheckCode, path: &Path) -> Result<()> {
-        let snapshot = format!("{}_{}", check_code.as_ref(), path.to_string_lossy());
-        let checks = test_path(
+    #[test_case(RuleCode::ERA001, Path::new("ERA001.py"); "ERA001")]
+    fn rules(rule_code: RuleCode, path: &Path) -> Result<()> {
+        let snapshot = format!("{}_{}", rule_code.as_ref(), path.to_string_lossy());
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/eradicate")
                .join(path)
                .as_path(),
-            &settings::Settings::for_rule(check_code),
+            &settings::Settings::for_rule(rule_code),
        )?;
-        insta::assert_yaml_snapshot!(snapshot, checks);
+        insta::assert_yaml_snapshot!(snapshot, diagnostics);
        Ok(())
    }
 }
--- a/src/eradicate/checks.rs
+++ b/src/eradicate/checks.rs
@@ -3,9 +3,9 @@ use rustpython_ast::Location;
 use crate::ast::types::Range;
 use crate::autofix::Fix;
 use crate::eradicate::detection::comment_contains_code;
-use crate::registry::{CheckCode, CheckKind};
+use crate::registry::RuleCode;
 use crate::settings::flags;
-use crate::{Check, Settings, SourceCodeLocator};
+use crate::{violations, Diagnostic, Settings, SourceCodeLocator};

 fn is_standalone_comment(line: &str) -> bool {
    for char in line.chars() {
@@ -25,20 +25,20 @@ pub fn commented_out_code(
    end: Location,
    settings: &Settings,
    autofix: flags::Autofix,
-) -> Option<Check> {
+) -> Option<Diagnostic> {
    let location = Location::new(start.row(), 0);
    let end_location = Location::new(end.row() + 1, 0);
    let line = locator.slice_source_code_range(&Range::new(location, end_location));

    // Verify that the comment is on its own line, and that it contains code.
    if is_standalone_comment(&line) && comment_contains_code(&line, &settings.task_tags[..]) {
-        let mut check = Check::new(CheckKind::CommentedOutCode, Range::new(start, end));
+        let mut diagnostic = Diagnostic::new(violations::CommentedOutCode, Range::new(start, end));
        if matches!(autofix, flags::Autofix::Enabled)
-            && settings.fixable.contains(&CheckCode::ERA001)
+            && settings.fixable.contains(&RuleCode::ERA001)
        {
-            check.amend(Fix::deletion(location, end_location));
+            diagnostic.amend(Fix::deletion(location, end_location));
        }
-        Some(check)
+        Some(diagnostic)
    } else {
        None
    }
--- a/src/eradicate/snapshots/rufferadicatetests__ERA001_ERA001.py.snap
+++ b/src/eradicate/snapshots/rufferadicatetests__ERA001_ERA001.py.snap
@@ -2,7 +2,8 @@
 source: src/eradicate/mod.rs
 expression: checks
 ---
- kind: CommentedOutCode
+- kind:
+    CommentedOutCode: ~
  location:
    row: 1
    column: 0
@@ -18,7 +19,8 @@ expression: checks
      row: 2
      column: 0
  parent: ~
- kind: CommentedOutCode
+- kind:
+    CommentedOutCode: ~
  location:
    row: 2
    column: 0
@@ -34,7 +36,8 @@ expression: checks
      row: 3
      column: 0
  parent: ~
- kind: CommentedOutCode
+- kind:
+    CommentedOutCode: ~
  location:
    row: 3
    column: 0
@@ -50,7 +53,8 @@ expression: checks
      row: 4
      column: 0
  parent: ~
- kind: CommentedOutCode
+- kind:
+    CommentedOutCode: ~
  location:
    row: 5
    column: 0
@@ -66,7 +70,8 @@ expression: checks
      row: 6
      column: 0
  parent: ~
- kind: CommentedOutCode
+- kind:
+    CommentedOutCode: ~
  location:
    row: 12
    column: 4
--- a/src/flake8_2020/mod.rs
+++ b/src/flake8_2020/mod.rs
@@ -1,4 +1,4 @@
-pub mod plugins;
+pub mod rules;

 #[cfg(test)]
 mod tests {
@@ -9,28 +9,28 @@ mod tests {
    use test_case::test_case;

    use crate::linter::test_path;
-    use crate::registry::CheckCode;
+    use crate::registry::RuleCode;
    use crate::settings;

-    #[test_case(CheckCode::YTT101, Path::new("YTT101.py"); "YTT101")]
-    #[test_case(CheckCode::YTT102, Path::new("YTT102.py"); "YTT102")]
-    #[test_case(CheckCode::YTT103, Path::new("YTT103.py"); "YTT103")]
-    #[test_case(CheckCode::YTT201, Path::new("YTT201.py"); "YTT201")]
-    #[test_case(CheckCode::YTT202, Path::new("YTT202.py"); "YTT202")]
-    #[test_case(CheckCode::YTT203, Path::new("YTT203.py"); "YTT203")]
-    #[test_case(CheckCode::YTT204, Path::new("YTT204.py"); "YTT204")]
-    #[test_case(CheckCode::YTT301, Path::new("YTT301.py"); "YTT301")]
-    #[test_case(CheckCode::YTT302, Path::new("YTT302.py"); "YTT302")]
-    #[test_case(CheckCode::YTT303, Path::new("YTT303.py"); "YTT303")]
-    fn checks(check_code: CheckCode, path: &Path) -> Result<()> {
-        let snapshot = format!("{}_{}", check_code.as_ref(), path.to_string_lossy());
-        let checks = test_path(
+    #[test_case(RuleCode::YTT101, Path::new("YTT101.py"); "YTT101")]
+    #[test_case(RuleCode::YTT102, Path::new("YTT102.py"); "YTT102")]
+    #[test_case(RuleCode::YTT103, Path::new("YTT103.py"); "YTT103")]
+    #[test_case(RuleCode::YTT201, Path::new("YTT201.py"); "YTT201")]
+    #[test_case(RuleCode::YTT202, Path::new("YTT202.py"); "YTT202")]
+    #[test_case(RuleCode::YTT203, Path::new("YTT203.py"); "YTT203")]
+    #[test_case(RuleCode::YTT204, Path::new("YTT204.py"); "YTT204")]
+    #[test_case(RuleCode::YTT301, Path::new("YTT301.py"); "YTT301")]
+    #[test_case(RuleCode::YTT302, Path::new("YTT302.py"); "YTT302")]
+    #[test_case(RuleCode::YTT303, Path::new("YTT303.py"); "YTT303")]
+    fn rules(rule_code: RuleCode, path: &Path) -> Result<()> {
+        let snapshot = format!("{}_{}", rule_code.as_ref(), path.to_string_lossy());
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_2020")
                .join(path)
                .as_path(),
-            &settings::Settings::for_rule(check_code),
+            &settings::Settings::for_rule(rule_code),
        )?;
-        insta::assert_yaml_snapshot!(snapshot, checks);
+        insta::assert_yaml_snapshot!(snapshot, diagnostics);
        Ok(())
    }
 }
--- a/src/flake8_2020/plugins.rs
+++ b/src/flake8_2020/plugins.rs
@@ -4,7 +4,8 @@ use rustpython_ast::{Cmpop, Constant, Expr, ExprKind, Located};
 use crate::ast::helpers::match_module_member;
 use crate::ast::types::Range;
 use crate::checkers::ast::Checker;
-use crate::registry::{Check, CheckCode, CheckKind};
+use crate::registry::{Diagnostic, RuleCode};
+use crate::violations;

 fn is_sys(checker: &Checker, expr: &Expr, target: &str) -> bool {
    match_module_member(
@@ -31,18 +32,17 @@ pub fn subscript(checker: &mut Checker, value: &Expr, slice: &Expr) {
                    ..
                } = &upper.node
                {
-                    if *i == BigInt::from(1)
-                        && checker.settings.enabled.contains(&CheckCode::YTT303)
+                    if *i == BigInt::from(1) && checker.settings.enabled.contains(&RuleCode::YTT303)
                    {
-                        checker.add_check(Check::new(
-                            CheckKind::SysVersionSlice1Referenced,
+                        checker.diagnostics.push(Diagnostic::new(
+                            violations::SysVersionSlice1Referenced,
                            Range::from_located(value),
                        ));
                    } else if *i == BigInt::from(3)
-                        && checker.settings.enabled.contains(&CheckCode::YTT101)
+                        && checker.settings.enabled.contains(&RuleCode::YTT101)
                    {
-                        checker.add_check(Check::new(
-                            CheckKind::SysVersionSlice3Referenced,
+                        checker.diagnostics.push(Diagnostic::new(
+                            violations::SysVersionSlice3Referenced,
                            Range::from_located(value),
                        ));
                    }
@@ -53,16 +53,16 @@ pub fn subscript(checker: &mut Checker, value: &Expr, slice: &Expr) {
                value: Constant::Int(i),
                ..
            } => {
-                if *i == BigInt::from(2) && checker.settings.enabled.contains(&CheckCode::YTT102) {
-                    checker.add_check(Check::new(
-                        CheckKind::SysVersion2Referenced,
+                if *i == BigInt::from(2) && checker.settings.enabled.contains(&RuleCode::YTT102) {
+                    checker.diagnostics.push(Diagnostic::new(
+                        violations::SysVersion2Referenced,
                        Range::from_located(value),
                    ));
                } else if *i == BigInt::from(0)
-                    && checker.settings.enabled.contains(&CheckCode::YTT301)
+                    && checker.settings.enabled.contains(&RuleCode::YTT301)
                {
-                    checker.add_check(Check::new(
-                        CheckKind::SysVersion0Referenced,
+                    checker.diagnostics.push(Diagnostic::new(
+                        violations::SysVersion0Referenced,
                        Range::from_located(value),
                    ));
                }
@@ -96,10 +96,10 @@ pub fn compare(checker: &mut Checker, left: &Expr, ops: &[Cmpop], comparators: &
                    ) = (ops, comparators)
                    {
                        if *n == BigInt::from(3)
-                            && checker.settings.enabled.contains(&CheckCode::YTT201)
+                            && checker.settings.enabled.contains(&RuleCode::YTT201)
                        {
-                            checker.add_check(Check::new(
-                                CheckKind::SysVersionInfo0Eq3Referenced,
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::SysVersionInfo0Eq3Referenced,
                                Range::from_located(left),
                            ));
                        }
@@ -117,9 +117,9 @@ pub fn compare(checker: &mut Checker, left: &Expr, ops: &[Cmpop], comparators: &
                        }],
                    ) = (ops, comparators)
                    {
-                        if checker.settings.enabled.contains(&CheckCode::YTT203) {
-                            checker.add_check(Check::new(
-                                CheckKind::SysVersionInfo1CmpInt,
+                        if checker.settings.enabled.contains(&RuleCode::YTT203) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::SysVersionInfo1CmpInt,
                                Range::from_located(left),
                            ));
                        }
@@ -143,9 +143,9 @@ pub fn compare(checker: &mut Checker, left: &Expr, ops: &[Cmpop], comparators: &
                }],
            ) = (ops, comparators)
            {
-                if checker.settings.enabled.contains(&CheckCode::YTT204) {
-                    checker.add_check(Check::new(
-                        CheckKind::SysVersionInfoMinorCmpInt,
+                if checker.settings.enabled.contains(&RuleCode::YTT204) {
+                    checker.diagnostics.push(Diagnostic::new(
+                        violations::SysVersionInfoMinorCmpInt,
                        Range::from_located(left),
                    ));
                }
@@ -169,15 +169,15 @@ pub fn compare(checker: &mut Checker, left: &Expr, ops: &[Cmpop], comparators: &
        ) = (ops, comparators)
        {
            if s.len() == 1 {
-                if checker.settings.enabled.contains(&CheckCode::YTT302) {
-                    checker.add_check(Check::new(
-                        CheckKind::SysVersionCmpStr10,
+                if checker.settings.enabled.contains(&RuleCode::YTT302) {
+                    checker.diagnostics.push(Diagnostic::new(
+                        violations::SysVersionCmpStr10,
                        Range::from_located(left),
                    ));
                }
-            } else if checker.settings.enabled.contains(&CheckCode::YTT103) {
-                checker.add_check(Check::new(
-                    CheckKind::SysVersionCmpStr3,
+            } else if checker.settings.enabled.contains(&RuleCode::YTT103) {
+                checker.diagnostics.push(Diagnostic::new(
+                    violations::SysVersionCmpStr3,
                    Range::from_located(left),
                ));
            }
@@ -194,8 +194,8 @@ pub fn name_or_attribute(checker: &mut Checker, expr: &Expr) {
        &checker.from_imports,
        &checker.import_aliases,
    ) {
-        checker.add_check(Check::new(
-            CheckKind::SixPY3Referenced,
+        checker.diagnostics.push(Diagnostic::new(
+            violations::SixPY3Referenced,
            Range::from_located(expr),
        ));
    }
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT101_YTT101.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT101_YTT101.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersionSlice3Referenced
+- kind:
+    SysVersionSlice3Referenced: ~
  location:
    row: 6
    column: 6
@@ -11,7 +12,8 @@ expression: checks
    column: 17
  fix: ~
  parent: ~
- kind: SysVersionSlice3Referenced
+- kind:
+    SysVersionSlice3Referenced: ~
  location:
    row: 7
    column: 6
@@ -20,7 +22,8 @@ expression: checks
    column: 13
  fix: ~
  parent: ~
- kind: SysVersionSlice3Referenced
+- kind:
+    SysVersionSlice3Referenced: ~
  location:
    row: 8
    column: 6
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT102_YTT102.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT102_YTT102.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersion2Referenced
+- kind:
+    SysVersion2Referenced: ~
  location:
    row: 4
    column: 11
@@ -11,7 +12,8 @@ expression: checks
    column: 22
  fix: ~
  parent: ~
- kind: SysVersion2Referenced
+- kind:
+    SysVersion2Referenced: ~
  location:
    row: 5
    column: 11
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT103_YTT103.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT103_YTT103.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersionCmpStr3
+- kind:
+    SysVersionCmpStr3: ~
  location:
    row: 4
    column: 0
@@ -11,7 +12,8 @@ expression: checks
    column: 7
  fix: ~
  parent: ~
- kind: SysVersionCmpStr3
+- kind:
+    SysVersionCmpStr3: ~
  location:
    row: 5
    column: 0
@@ -20,7 +22,8 @@ expression: checks
    column: 11
  fix: ~
  parent: ~
- kind: SysVersionCmpStr3
+- kind:
+    SysVersionCmpStr3: ~
  location:
    row: 6
    column: 0
@@ -29,7 +32,8 @@ expression: checks
    column: 11
  fix: ~
  parent: ~
- kind: SysVersionCmpStr3
+- kind:
+    SysVersionCmpStr3: ~
  location:
    row: 7
    column: 0
@@ -38,7 +42,8 @@ expression: checks
    column: 11
  fix: ~
  parent: ~
- kind: SysVersionCmpStr3
+- kind:
+    SysVersionCmpStr3: ~
  location:
    row: 8
    column: 0
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT201_YTT201.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT201_YTT201.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersionInfo0Eq3Referenced
+- kind:
+    SysVersionInfo0Eq3Referenced: ~
  location:
    row: 7
    column: 6
@@ -11,7 +12,8 @@ expression: checks
    column: 25
  fix: ~
  parent: ~
- kind: SysVersionInfo0Eq3Referenced
+- kind:
+    SysVersionInfo0Eq3Referenced: ~
  location:
    row: 8
    column: 6
@@ -20,7 +22,8 @@ expression: checks
    column: 21
  fix: ~
  parent: ~
- kind: SysVersionInfo0Eq3Referenced
+- kind:
+    SysVersionInfo0Eq3Referenced: ~
  location:
    row: 9
    column: 6
@@ -29,7 +32,8 @@ expression: checks
    column: 25
  fix: ~
  parent: ~
- kind: SysVersionInfo0Eq3Referenced
+- kind:
+    SysVersionInfo0Eq3Referenced: ~
  location:
    row: 10
    column: 6
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT202_YTT202.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT202_YTT202.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SixPY3Referenced
+- kind:
+    SixPY3Referenced: ~
  location:
    row: 4
    column: 3
@@ -11,7 +12,8 @@ expression: checks
    column: 10
  fix: ~
  parent: ~
- kind: SixPY3Referenced
+- kind:
+    SixPY3Referenced: ~
  location:
    row: 6
    column: 3
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT203_YTT203.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT203_YTT203.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersionInfo1CmpInt
+- kind:
+    SysVersionInfo1CmpInt: ~
  location:
    row: 4
    column: 0
@@ -11,7 +12,8 @@ expression: checks
    column: 19
  fix: ~
  parent: ~
- kind: SysVersionInfo1CmpInt
+- kind:
+    SysVersionInfo1CmpInt: ~
  location:
    row: 5
    column: 0
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT204_YTT204.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT204_YTT204.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersionInfoMinorCmpInt
+- kind:
+    SysVersionInfoMinorCmpInt: ~
  location:
    row: 4
    column: 0
@@ -11,7 +12,8 @@ expression: checks
    column: 22
  fix: ~
  parent: ~
- kind: SysVersionInfoMinorCmpInt
+- kind:
+    SysVersionInfoMinorCmpInt: ~
  location:
    row: 5
    column: 0
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT301_YTT301.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT301_YTT301.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersion0Referenced
+- kind:
+    SysVersion0Referenced: ~
  location:
    row: 4
    column: 11
@@ -11,7 +12,8 @@ expression: checks
    column: 22
  fix: ~
  parent: ~
- kind: SysVersion0Referenced
+- kind:
+    SysVersion0Referenced: ~
  location:
    row: 5
    column: 11
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT302_YTT302.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT302_YTT302.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersionCmpStr10
+- kind:
+    SysVersionCmpStr10: ~
  location:
    row: 4
    column: 0
@@ -11,7 +12,8 @@ expression: checks
    column: 7
  fix: ~
  parent: ~
- kind: SysVersionCmpStr10
+- kind:
+    SysVersionCmpStr10: ~
  location:
    row: 5
    column: 0
@@ -20,7 +22,8 @@ expression: checks
    column: 11
  fix: ~
  parent: ~
- kind: SysVersionCmpStr10
+- kind:
+    SysVersionCmpStr10: ~
  location:
    row: 6
    column: 0
@@ -29,7 +32,8 @@ expression: checks
    column: 11
  fix: ~
  parent: ~
- kind: SysVersionCmpStr10
+- kind:
+    SysVersionCmpStr10: ~
  location:
    row: 7
    column: 0
@@ -38,7 +42,8 @@ expression: checks
    column: 11
  fix: ~
  parent: ~
- kind: SysVersionCmpStr10
+- kind:
+    SysVersionCmpStr10: ~
  location:
    row: 8
    column: 0
--- a/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT303_YTT303.py.snap
+++ b/src/flake8_2020/snapshots/ruff__flake8_2020testsYTT303_YTT303.py.snap
@@ -2,7 +2,8 @@
 source: src/flake8_2020/mod.rs
 expression: checks
 ---
- kind: SysVersionSlice1Referenced
+- kind:
+    SysVersionSlice1Referenced: ~
  location:
    row: 4
    column: 6
@@ -11,7 +12,8 @@ expression: checks
    column: 17
  fix: ~
  parent: ~
- kind: SysVersionSlice1Referenced
+- kind:
+    SysVersionSlice1Referenced: ~
  location:
    row: 5
    column: 6
--- a/src/flake8_annotations/mod.rs
+++ b/src/flake8_annotations/mod.rs
@@ -1,6 +1,6 @@
 mod fixes;
 pub mod helpers;
-pub mod plugins;
+pub mod rules;
 pub mod settings;

 #[cfg(test)]
@@ -10,36 +10,36 @@ mod tests {
    use anyhow::Result;

    use crate::linter::test_path;
-    use crate::registry::CheckCode;
+    use crate::registry::RuleCode;
    use crate::{flake8_annotations, Settings};

    #[test]
    fn defaults() -> Result<()> {
-        let checks = test_path(
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_annotations/annotation_presence.py"),
            &Settings {
                ..Settings::for_rules(vec![
-                    CheckCode::ANN001,
-                    CheckCode::ANN002,
-                    CheckCode::ANN003,
-                    CheckCode::ANN101,
-                    CheckCode::ANN102,
-                    CheckCode::ANN201,
-                    CheckCode::ANN202,
-                    CheckCode::ANN204,
-                    CheckCode::ANN205,
-                    CheckCode::ANN206,
-                    CheckCode::ANN401,
+                    RuleCode::ANN001,
+                    RuleCode::ANN002,
+                    RuleCode::ANN003,
+                    RuleCode::ANN101,
+                    RuleCode::ANN102,
+                    RuleCode::ANN201,
+                    RuleCode::ANN202,
+                    RuleCode::ANN204,
+                    RuleCode::ANN205,
+                    RuleCode::ANN206,
+                    RuleCode::ANN401,
                ])
            },
        )?;
-        insta::assert_yaml_snapshot!(checks);
+        insta::assert_yaml_snapshot!(diagnostics);
        Ok(())
    }

    #[test]
    fn suppress_dummy_args() -> Result<()> {
-        let checks = test_path(
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_annotations/suppress_dummy_args.py"),
            &Settings {
                flake8_annotations: flake8_annotations::settings::Settings {
@@ -49,21 +49,21 @@ mod tests {
                    allow_star_arg_any: false,
                },
                ..Settings::for_rules(vec![
-                    CheckCode::ANN001,
-                    CheckCode::ANN002,
-                    CheckCode::ANN003,
-                    CheckCode::ANN101,
-                    CheckCode::ANN102,
+                    RuleCode::ANN001,
+                    RuleCode::ANN002,
+                    RuleCode::ANN003,
+                    RuleCode::ANN101,
+                    RuleCode::ANN102,
                ])
            },
        )?;
-        insta::assert_yaml_snapshot!(checks);
+        insta::assert_yaml_snapshot!(diagnostics);
        Ok(())
    }

    #[test]
    fn mypy_init_return() -> Result<()> {
-        let checks = test_path(
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_annotations/mypy_init_return.py"),
            &Settings {
                flake8_annotations: flake8_annotations::settings::Settings {
@@ -73,21 +73,21 @@ mod tests {
                    allow_star_arg_any: false,
                },
                ..Settings::for_rules(vec![
-                    CheckCode::ANN201,
-                    CheckCode::ANN202,
-                    CheckCode::ANN204,
-                    CheckCode::ANN205,
-                    CheckCode::ANN206,
+                    RuleCode::ANN201,
+                    RuleCode::ANN202,
+                    RuleCode::ANN204,
+                    RuleCode::ANN205,
+                    RuleCode::ANN206,
                ])
            },
        )?;
-        insta::assert_yaml_snapshot!(checks);
+        insta::assert_yaml_snapshot!(diagnostics);
        Ok(())
    }

    #[test]
    fn suppress_none_returning() -> Result<()> {
-        let checks = test_path(
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_annotations/suppress_none_returning.py"),
            &Settings {
                flake8_annotations: flake8_annotations::settings::Settings {
@@ -97,21 +97,21 @@ mod tests {
                    allow_star_arg_any: false,
                },
                ..Settings::for_rules(vec![
-                    CheckCode::ANN201,
-                    CheckCode::ANN202,
-                    CheckCode::ANN204,
-                    CheckCode::ANN205,
-                    CheckCode::ANN206,
+                    RuleCode::ANN201,
+                    RuleCode::ANN202,
+                    RuleCode::ANN204,
+                    RuleCode::ANN205,
+                    RuleCode::ANN206,
                ])
            },
        )?;
-        insta::assert_yaml_snapshot!(checks);
+        insta::assert_yaml_snapshot!(diagnostics);
        Ok(())
    }

    #[test]
    fn allow_star_arg_any() -> Result<()> {
-        let checks = test_path(
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_annotations/allow_star_arg_any.py"),
            &Settings {
                flake8_annotations: flake8_annotations::settings::Settings {
@@ -120,28 +120,28 @@ mod tests {
                    suppress_none_returning: false,
                    allow_star_arg_any: true,
                },
-                ..Settings::for_rules(vec![CheckCode::ANN401])
+                ..Settings::for_rules(vec![RuleCode::ANN401])
            },
        )?;
-        insta::assert_yaml_snapshot!(checks);
+        insta::assert_yaml_snapshot!(diagnostics);
        Ok(())
    }

    #[test]
    fn allow_overload() -> Result<()> {
-        let checks = test_path(
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_annotations/allow_overload.py"),
            &Settings {
                ..Settings::for_rules(vec![
-                    CheckCode::ANN201,
-                    CheckCode::ANN202,
-                    CheckCode::ANN204,
-                    CheckCode::ANN205,
-                    CheckCode::ANN206,
+                    RuleCode::ANN201,
+                    RuleCode::ANN202,
+                    RuleCode::ANN204,
+                    RuleCode::ANN205,
+                    RuleCode::ANN206,
                ])
            },
        )?;
-        insta::assert_yaml_snapshot!(checks);
+        insta::assert_yaml_snapshot!(diagnostics);
        Ok(())
    }
 }
--- a/src/flake8_annotations/plugins.rs
+++ b/src/flake8_annotations/plugins.rs
@@ -8,9 +8,9 @@ use crate::checkers::ast::Checker;
 use crate::docstrings::definition::{Definition, DefinitionKind};
 use crate::flake8_annotations::fixes;
 use crate::flake8_annotations::helpers::match_function_def;
-use crate::registry::{CheckCode, CheckKind};
+use crate::registry::RuleCode;
 use crate::visibility::Visibility;
-use crate::{visibility, Check};
+use crate::{violations, visibility, Diagnostic};

 #[derive(Default)]
 struct ReturnStatementVisitor<'a> {
@@ -57,8 +57,8 @@ where
    F: FnOnce() -> String,
 {
    if checker.match_typing_expr(annotation, "Any") {
-        checker.add_check(Check::new(
-            CheckKind::DynamicallyTypedExpression(func()),
+        checker.diagnostics.push(Diagnostic::new(
+            violations::DynamicallyTypedExpression(func()),
            Range::from_located(annotation),
        ));
    };
@@ -85,16 +85,16 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                .chain(args.kwonlyargs.iter())
            {
                if let Some(expr) = &arg.node.annotation {
-                    if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                    if checker.settings.enabled.contains(&RuleCode::ANN401) {
                        check_dynamically_typed(checker, expr, || arg.node.arg.to_string());
                    };
                } else {
                    if !(checker.settings.flake8_annotations.suppress_dummy_args
                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
                    {
-                        if checker.settings.enabled.contains(&CheckCode::ANN001) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingTypeFunctionArgument(arg.node.arg.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN001) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingTypeFunctionArgument(arg.node.arg.to_string()),
                                Range::from_located(arg),
                            ));
                        }
@@ -106,7 +106,7 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
            if let Some(arg) = &args.vararg {
                if let Some(expr) = &arg.node.annotation {
                    if !checker.settings.flake8_annotations.allow_star_arg_any {
-                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                        if checker.settings.enabled.contains(&RuleCode::ANN401) {
                            let name = arg.node.arg.to_string();
                            check_dynamically_typed(checker, expr, || format!("*{name}"));
                        }
@@ -115,9 +115,9 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                    if !(checker.settings.flake8_annotations.suppress_dummy_args
                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
                    {
-                        if checker.settings.enabled.contains(&CheckCode::ANN002) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingTypeArgs(arg.node.arg.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN002) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingTypeArgs(arg.node.arg.to_string()),
                                Range::from_located(arg),
                            ));
                        }
@@ -129,7 +129,7 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
            if let Some(arg) = &args.kwarg {
                if let Some(expr) = &arg.node.annotation {
                    if !checker.settings.flake8_annotations.allow_star_arg_any {
-                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                        if checker.settings.enabled.contains(&RuleCode::ANN401) {
                            let name = arg.node.arg.to_string();
                            check_dynamically_typed(checker, expr, || format!("**{name}"));
                        }
@@ -138,9 +138,9 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                    if !(checker.settings.flake8_annotations.suppress_dummy_args
                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
                    {
-                        if checker.settings.enabled.contains(&CheckCode::ANN003) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingTypeKwargs(arg.node.arg.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN003) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingTypeKwargs(arg.node.arg.to_string()),
                                Range::from_located(arg),
                            ));
                        }
@@ -150,7 +150,7 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V

            // ANN201, ANN202, ANN401
            if let Some(expr) = &returns {
-                if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                if checker.settings.enabled.contains(&RuleCode::ANN401) {
                    check_dynamically_typed(checker, expr, || name.to_string());
                };
            } else {
@@ -164,17 +164,17 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V

                match visibility {
                    Visibility::Public => {
-                        if checker.settings.enabled.contains(&CheckCode::ANN201) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingReturnTypePublicFunction(name.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN201) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingReturnTypePublicFunction(name.to_string()),
                                helpers::identifier_range(stmt, checker.locator),
                            ));
                        }
                    }
                    Visibility::Private => {
-                        if checker.settings.enabled.contains(&CheckCode::ANN202) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingReturnTypePrivateFunction(name.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN202) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingReturnTypePrivateFunction(name.to_string()),
                                helpers::identifier_range(stmt, checker.locator),
                            ));
                        }
@@ -203,16 +203,16 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                // ANN401 for dynamically typed arguments
                if let Some(annotation) = &arg.node.annotation {
                    has_any_typed_arg = true;
-                    if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                    if checker.settings.enabled.contains(&RuleCode::ANN401) {
                        check_dynamically_typed(checker, annotation, || arg.node.arg.to_string());
                    }
                } else {
                    if !(checker.settings.flake8_annotations.suppress_dummy_args
                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
                    {
-                        if checker.settings.enabled.contains(&CheckCode::ANN001) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingTypeFunctionArgument(arg.node.arg.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN001) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingTypeFunctionArgument(arg.node.arg.to_string()),
                                Range::from_located(arg),
                            ));
                        }
@@ -225,7 +225,7 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                has_any_typed_arg = true;
                if let Some(expr) = &arg.node.annotation {
                    if !checker.settings.flake8_annotations.allow_star_arg_any {
-                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                        if checker.settings.enabled.contains(&RuleCode::ANN401) {
                            let name = arg.node.arg.to_string();
                            check_dynamically_typed(checker, expr, || format!("*{name}"));
                        }
@@ -234,9 +234,9 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                    if !(checker.settings.flake8_annotations.suppress_dummy_args
                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
                    {
-                        if checker.settings.enabled.contains(&CheckCode::ANN002) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingTypeArgs(arg.node.arg.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN002) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingTypeArgs(arg.node.arg.to_string()),
                                Range::from_located(arg),
                            ));
                        }
@@ -249,7 +249,7 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                has_any_typed_arg = true;
                if let Some(expr) = &arg.node.annotation {
                    if !checker.settings.flake8_annotations.allow_star_arg_any {
-                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                        if checker.settings.enabled.contains(&RuleCode::ANN401) {
                            let name = arg.node.arg.to_string();
                            check_dynamically_typed(checker, expr, || format!("**{name}"));
                        }
@@ -258,9 +258,9 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                    if !(checker.settings.flake8_annotations.suppress_dummy_args
                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
                    {
-                        if checker.settings.enabled.contains(&CheckCode::ANN003) {
-                            checker.add_check(Check::new(
-                                CheckKind::MissingTypeKwargs(arg.node.arg.to_string()),
+                        if checker.settings.enabled.contains(&RuleCode::ANN003) {
+                            checker.diagnostics.push(Diagnostic::new(
+                                violations::MissingTypeKwargs(arg.node.arg.to_string()),
                                Range::from_located(arg),
                            ));
                        }
@@ -273,16 +273,16 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                if let Some(arg) = args.args.first() {
                    if arg.node.annotation.is_none() {
                        if visibility::is_classmethod(checker, cast::decorator_list(stmt)) {
-                            if checker.settings.enabled.contains(&CheckCode::ANN102) {
-                                checker.add_check(Check::new(
-                                    CheckKind::MissingTypeCls(arg.node.arg.to_string()),
+                            if checker.settings.enabled.contains(&RuleCode::ANN102) {
+                                checker.diagnostics.push(Diagnostic::new(
+                                    violations::MissingTypeCls(arg.node.arg.to_string()),
                                    Range::from_located(arg),
                                ));
                            }
                        } else {
-                            if checker.settings.enabled.contains(&CheckCode::ANN101) {
-                                checker.add_check(Check::new(
-                                    CheckKind::MissingTypeSelf(arg.node.arg.to_string()),
+                            if checker.settings.enabled.contains(&RuleCode::ANN101) {
+                                checker.diagnostics.push(Diagnostic::new(
+                                    violations::MissingTypeSelf(arg.node.arg.to_string()),
                                    Range::from_located(arg),
                                ));
                            }
@@ -293,7 +293,7 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V

            // ANN201, ANN202
            if let Some(expr) = &returns {
-                if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                if checker.settings.enabled.contains(&RuleCode::ANN401) {
                    check_dynamically_typed(checker, expr, || name.to_string());
                }
            } else {
@@ -306,62 +306,62 @@ pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &V
                }

                if visibility::is_classmethod(checker, cast::decorator_list(stmt)) {
-                    if checker.settings.enabled.contains(&CheckCode::ANN206) {
-                        checker.add_check(Check::new(
-                            CheckKind::MissingReturnTypeClassMethod(name.to_string()),
+                    if checker.settings.enabled.contains(&RuleCode::ANN206) {
+                        checker.diagnostics.push(Diagnostic::new(
+                            violations::MissingReturnTypeClassMethod(name.to_string()),
                            helpers::identifier_range(stmt, checker.locator),
                        ));
                    }
                } else if visibility::is_staticmethod(checker, cast::decorator_list(stmt)) {
-                    if checker.settings.enabled.contains(&CheckCode::ANN205) {
-                        checker.add_check(Check::new(
-                            CheckKind::MissingReturnTypeStaticMethod(name.to_string()),
+                    if checker.settings.enabled.contains(&RuleCode::ANN205) {
+                        checker.diagnostics.push(Diagnostic::new(
+                            violations::MissingReturnTypeStaticMethod(name.to_string()),
                            helpers::identifier_range(stmt, checker.locator),
                        ));
                    }
                } else if visibility::is_init(stmt) {
                    // Allow omission of return annotation in `__init__` functions, as long as at
                    // least one argument is typed.
-                    if checker.settings.enabled.contains(&CheckCode::ANN204) {
+                    if checker.settings.enabled.contains(&RuleCode::ANN204) {
                        if !(checker.settings.flake8_annotations.mypy_init_return
                            && has_any_typed_arg)
                        {
-                            let mut check = Check::new(
-                                CheckKind::MissingReturnTypeSpecialMethod(name.to_string()),
+                            let mut diagnostic = Diagnostic::new(
+                                violations::MissingReturnTypeSpecialMethod(name.to_string()),
                                helpers::identifier_range(stmt, checker.locator),
                            );
-                            if checker.patch(check.kind.code()) {
+                            if checker.patch(diagnostic.kind.code()) {
                                match fixes::add_return_none_annotation(checker.locator, stmt) {
                                    Ok(fix) => {
-                                        check.amend(fix);
+                                        diagnostic.amend(fix);
                                    }
                                    Err(e) => error!("Failed to generate fix: {e}"),
                                }
                            }
-                            checker.add_check(check);
+                            checker.diagnostics.push(diagnostic);
                        }
                    }
                } else if visibility::is_magic(stmt) {
-                    if checker.settings.enabled.contains(&CheckCode::ANN204) {
-                        checker.add_check(Check::new(
-                            CheckKind::MissingReturnTypeSpecialMethod(name.to_string()),
+                    if checker.settings.enabled.contains(&RuleCode::ANN204) {
+                        checker.diagnostics.push(Diagnostic::new(
+                            violations::MissingReturnTypeSpecialMethod(name.to_string()),
                            helpers::identifier_range(stmt, checker.locator),
                        ));
                    }
                } else {
                    match visibility {
                        Visibility::Public => {
-                            if checker.settings.enabled.contains(&CheckCode::ANN201) {
-                                checker.add_check(Check::new(
-                                    CheckKind::MissingReturnTypePublicFunction(name.to_string()),
+                            if checker.settings.enabled.contains(&RuleCode::ANN201) {
+                                checker.diagnostics.push(Diagnostic::new(
+                                    violations::MissingReturnTypePublicFunction(name.to_string()),
                                    helpers::identifier_range(stmt, checker.locator),
                                ));
                            }
                        }
                        Visibility::Private => {
-                            if checker.settings.enabled.contains(&CheckCode::ANN202) {
-                                checker.add_check(Check::new(
-                                    CheckKind::MissingReturnTypePrivateFunction(name.to_string()),
+                            if checker.settings.enabled.contains(&RuleCode::ANN202) {
+                                checker.diagnostics.push(Diagnostic::new(
+                                    violations::MissingReturnTypePrivateFunction(name.to_string()),
                                    helpers::identifier_range(stmt, checker.locator),
                                ));
                            }
--- a/src/flake8_bandit/checks/assert_used.rs
+++ b/src/flake8_bandit/checks/assert_used.rs
@@ -1,9 +0,0 @@
-use rustpython_ast::{Located, StmtKind};
-
-use crate::ast::types::Range;
-use crate::registry::{Check, CheckKind};
-
-/// S101
-pub fn assert_used(stmt: &Located<StmtKind>) -> Check {
-    Check::new(CheckKind::AssertUsed, Range::from_located(stmt))
-}
--- a/src/flake8_bandit/checks/exec_used.rs
+++ b/src/flake8_bandit/checks/exec_used.rs
@@ -1,15 +0,0 @@
-use rustpython_ast::{Expr, ExprKind};
-
-use crate::ast::types::Range;
-use crate::registry::{Check, CheckKind};
-
-/// S102
-pub fn exec_used(expr: &Expr, func: &Expr) -> Option<Check> {
-    let ExprKind::Name { id, .. } = &func.node else {
-        return None;
-    };
-    if id != "exec" {
-        return None;
-    }
-    Some(Check::new(CheckKind::ExecUsed, Range::from_located(expr)))
-}
--- a/src/flake8_bandit/checks/hardcoded_bind_all_interfaces.rs
+++ b/src/flake8_bandit/checks/hardcoded_bind_all_interfaces.rs
@@ -1,11 +0,0 @@
-use crate::ast::types::Range;
-use crate::registry::{Check, CheckKind};
-
-/// S104
-pub fn hardcoded_bind_all_interfaces(value: &str, range: &Range) -> Option<Check> {
-    if value == "0.0.0.0" {
-        Some(Check::new(CheckKind::HardcodedBindAllInterfaces, *range))
-    } else {
-        None
-    }
-}
--- a/src/flake8_bandit/checks/hardcoded_tmp_directory.rs
+++ b/src/flake8_bandit/checks/hardcoded_tmp_directory.rs
@@ -1,16 +0,0 @@
-use rustpython_ast::Expr;
-
-use crate::ast::types::Range;
-use crate::registry::{Check, CheckKind};
-
-/// S108
-pub fn hardcoded_tmp_directory(expr: &Expr, value: &str, prefixes: &[String]) -> Option<Check> {
-    if prefixes.iter().any(|prefix| value.starts_with(prefix)) {
-        Some(Check::new(
-            CheckKind::HardcodedTempFile(value.to_string()),
-            Range::from_located(expr),
-        ))
-    } else {
-        None
-    }
-}
--- a/src/flake8_bandit/mod.rs
+++ b/src/flake8_bandit/mod.rs
@@ -1,5 +1,5 @@
-pub mod checks;
 mod helpers;
+pub mod rules;
 pub mod settings;

 #[cfg(test)]
@@ -10,32 +10,36 @@ mod tests {
    use test_case::test_case;

    use crate::linter::test_path;
-    use crate::registry::CheckCode;
+    use crate::registry::RuleCode;
    use crate::{flake8_bandit, Settings};

-    #[test_case(CheckCode::S101, Path::new("S101.py"); "S101")]
-    #[test_case(CheckCode::S102, Path::new("S102.py"); "S102")]
-    #[test_case(CheckCode::S103, Path::new("S103.py"); "S103")]
-    #[test_case(CheckCode::S104, Path::new("S104.py"); "S104")]
-    #[test_case(CheckCode::S105, Path::new("S105.py"); "S105")]
-    #[test_case(CheckCode::S106, Path::new("S106.py"); "S106")]
-    #[test_case(CheckCode::S107, Path::new("S107.py"); "S107")]
-    #[test_case(CheckCode::S108, Path::new("S108.py"); "S108")]
-    fn checks(check_code: CheckCode, path: &Path) -> Result<()> {
-        let snapshot = format!("{}_{}", check_code.as_ref(), path.to_string_lossy());
-        let checks = test_path(
+    #[test_case(RuleCode::S101, Path::new("S101.py"); "S101")]
+    #[test_case(RuleCode::S102, Path::new("S102.py"); "S102")]
+    #[test_case(RuleCode::S103, Path::new("S103.py"); "S103")]
+    #[test_case(RuleCode::S104, Path::new("S104.py"); "S104")]
+    #[test_case(RuleCode::S105, Path::new("S105.py"); "S105")]
+    #[test_case(RuleCode::S106, Path::new("S106.py"); "S106")]
+    #[test_case(RuleCode::S107, Path::new("S107.py"); "S107")]
+    #[test_case(RuleCode::S108, Path::new("S108.py"); "S108")]
+    #[test_case(RuleCode::S113, Path::new("S113.py"); "S113")]
+    #[test_case(RuleCode::S324, Path::new("S324.py"); "S324")]
+    #[test_case(RuleCode::S501, Path::new("S501.py"); "S501")]
+    #[test_case(RuleCode::S506, Path::new("S506.py"); "S506")]
+    fn rules(rule_code: RuleCode, path: &Path) -> Result<()> {
+        let snapshot = format!("{}_{}", rule_code.as_ref(), path.to_string_lossy());
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_bandit")
                .join(path)
                .as_path(),
-            &Settings::for_rule(check_code),
+            &Settings::for_rule(rule_code),
        )?;
-        insta::assert_yaml_snapshot!(snapshot, checks);
+        insta::assert_yaml_snapshot!(snapshot, diagnostics);
        Ok(())
    }

    #[test]
    fn check_hardcoded_tmp_additional_dirs() -> Result<()> {
-        let checks = test_path(
+        let diagnostics = test_path(
            Path::new("./resources/test/fixtures/flake8_bandit/S108.py"),
            &Settings {
                flake8_bandit: flake8_bandit::settings::Settings {
@@ -46,10 +50,10 @@ mod tests {
                        "/foo".to_string(),
                    ],
                },
-                ..Settings::for_rule(CheckCode::S108)
+                ..Settings::for_rule(RuleCode::S108)
            },
        )?;
-        insta::assert_yaml_snapshot!("S108_extend", checks);
+        insta::assert_yaml_snapshot!("S108_extend", diagnostics);
        Ok(())
    }
 }
--- a/src/flake8_bandit/rules/assert_used.rs
+++ b/src/flake8_bandit/rules/assert_used.rs
@@ -0,0 +1,10 @@
+use rustpython_ast::{Located, StmtKind};
+
+use crate::ast::types::Range;
+use crate::registry::Diagnostic;
+use crate::violations;
+
+/// S101
+pub fn assert_used(stmt: &Located<StmtKind>) -> Diagnostic {
+    Diagnostic::new(violations::AssertUsed, Range::from_located(stmt))
+}
--- a/src/flake8_bandit/checks/bad_file_permissions.rs
+++ b/src/flake8_bandit/checks/bad_file_permissions.rs
@@ -5,7 +5,8 @@ use rustpython_ast::{Constant, Expr, ExprKind, Keyword, Operator};

 use crate::ast::helpers::{compose_call_path, match_module_member, SimpleCallArgs};
 use crate::ast::types::Range;
-use crate::registry::{Check, CheckKind};
+use crate::registry::Diagnostic;
+use crate::violations;

 const WRITE_WORLD: u16 = 0o2;
 const EXECUTE_GROUP: u16 = 0o10;
@@ -86,18 +87,18 @@ fn get_int_value(expr: &Expr) -> Option<u16> {
 /// S103
 pub fn bad_file_permissions(
    func: &Expr,
-    args: &Vec<Expr>,
-    keywords: &Vec<Keyword>,
+    args: &[Expr],
+    keywords: &[Keyword],
    from_imports: &FxHashMap<&str, FxHashSet<&str>>,
    import_aliases: &FxHashMap<&str, &str>,
-) -> Option<Check> {
+) -> Option<Diagnostic> {
    if match_module_member(func, "os", "chmod", from_imports, import_aliases) {
        let call_args = SimpleCallArgs::new(args, keywords);
        if let Some(mode_arg) = call_args.get_argument("mode", Some(1)) {
            if let Some(int_value) = get_int_value(mode_arg) {
                if (int_value & WRITE_WORLD > 0) || (int_value & EXECUTE_GROUP > 0) {
-                    return Some(Check::new(
-                        CheckKind::BadFilePermissions(int_value),
+                    return Some(Diagnostic::new(
+                        violations::BadFilePermissions(int_value),
                        Range::from_located(mode_arg),
                    ));
                }
--- a/Show More
+++ b/Show More