Bump version to 0.0.222

Before

```
resources/test/fixtures/flake8_simplify/SIM208.py:1:13: SIM208 Use `a` instead of `not (not a)`
  |
1 | if not (not a):  # SIM208
  |             ^ SIM208
  |
  = help: Replace with `a`

resources/test/fixtures/flake8_simplify/SIM208.py:4:14: SIM208 Use `a == b` instead of `not (not a == b)`
  |
4 | if not (not (a == b)):  # SIM208
  |              ^^^^^^ SIM208
  |
  = help: Replace with `a == b`
```

After

```
resources/test/fixtures/flake8_simplify/SIM208.py:1:4: SIM208 Use `a` instead of `not (not a)`
  |
1 | if not (not a):  # SIM208
  |    ^^^^^^^^^^^ SIM208
  |
  = help: Replace with `a`

resources/test/fixtures/flake8_simplify/SIM208.py:4:4: SIM208 Use `a == b` instead of `not (not a == b)`
  |
4 | if not (not (a == b)):  # SIM208
  |    ^^^^^^^^^^^^^^^^^^ SIM208
  |
  = help: Replace with `a == 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`).
+-->

.github/workflows/ci.yaml

@@ -26,25 +26,12 @@ jobs:
           profile: minimal
           toolchain: nightly-2022-11-01
           override: true
-          components: rustfmt
-      - uses: actions/cache@v3
-        env:
-          cache-name: cache-cargo
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-build-${{ env.cache-name }}-
-            ${{ runner.os }}-build-
-            ${{ runner.os }}-
-      - run: cargo build --all --release
-      - run: ./target/release/ruff_dev generate-all
+      - uses: Swatinem/rust-cache@v1
+      - run: cargo build --all
+      - run: ./target/debug/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       - run: git diff --quiet README.md || echo "::error file=README.md::This file is outdated.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-      - run: git diff --quiet src/registry_gen.rs || echo "::error file=src/registry_gen.rs::This file is outdated.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"
@@ -57,18 +44,6 @@ jobs:
           toolchain: nightly-2022-11-01
           override: true
           components: rustfmt
-      - uses: actions/cache@v3
-        env:
-          cache-name: cache-cargo
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-build-${{ env.cache-name }}-
-            ${{ runner.os }}-build-
-            ${{ runner.os }}-
       - run: cargo fmt --all --check
 
   cargo_clippy:
@@ -83,20 +58,9 @@ jobs:
           override: true
           components: clippy
           target: wasm32-unknown-unknown
-      - uses: actions/cache@v3
-        env:
-          cache-name: cache-cargo
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-build-${{ env.cache-name }}-
-            ${{ runner.os }}-build-
-            ${{ runner.os }}-
+      - uses: Swatinem/rust-cache@v1
       - run: cargo clippy --workspace --all-targets --all-features -- -D warnings -W clippy::pedantic
-      - run: cargo clippy --workspace --target wasm32-unknown-unknown --all-features -- -D warnings -W clippy::pedantic
+      - run: cargo clippy -p ruff --target wasm32-unknown-unknown --all-features -- -D warnings -W clippy::pedantic
 
   cargo-test:
     name: "cargo test"
@@ -108,25 +72,17 @@ jobs:
           profile: minimal
           toolchain: nightly-2022-11-01
           override: true
-      - uses: actions/cache@v3
-        env:
-          cache-name: cache-cargo
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-build-${{ env.cache-name }}-
-            ${{ runner.os }}-build-
-            ${{ runner.os }}-
+      - uses: Swatinem/rust-cache@v1
       - run: cargo install cargo-insta
       - run: pip install black[d]==22.12.0
       - name: Run tests
         run: |
           cargo insta test --all --delete-unreferenced-snapshots
           git diff --exit-code
-      - run: cargo test --package ruff --test black_compatibility_test -- --ignored
+      - run: cargo test --package ruff_cli --test black_compatibility_test -- --ignored
+      # Check for broken links in the documentation.
+      # Setting RUSTDOCFLAGS because `cargo doc --check` isn't yet implemented (https://github.com/rust-lang/cargo/issues/10025).
+      - run: RUSTDOCFLAGS="-D warnings" cargo doc --all --no-deps
 
 # TODO(charlie): Re-enable the `wasm-pack` tests.
 # See: https://github.com/charliermarsh/ruff/issues/1425
@@ -168,22 +124,11 @@ jobs:
           profile: minimal
           toolchain: nightly-2022-11-01
           override: true
+      - uses: Swatinem/rust-cache@v1
       - uses: actions/setup-python@v4
         with:
           python-version: "3.11"
       - run: pip install maturin
-      - uses: actions/cache@v3
-        env:
-          cache-name: cache-cargo
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-build-${{ env.cache-name }}-
-            ${{ runner.os }}-build-
-            ${{ runner.os }}-
       - run: maturin build -b bin
 
   typos:

.github/workflows/playground.yaml

@@ -31,7 +31,7 @@ jobs:
       - uses: jetli/wasm-pack-action@v0.4.0
       - uses: jetli/wasm-bindgen-action@v0.2.0
       - name: "Run wasm-pack"
-        run: wasm-pack build --target web --out-dir playground/src/pkg
+        run: wasm-pack build --target web --out-dir playground/src/pkg . -- -p ruff
       - name: "Install Node dependencies"
         run: npm ci
         working-directory: playground

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.211
+    rev: v0.0.222
     hooks:
       - id: ruff
 

BREAKING_CHANGES.md

@@ -1,5 +1,20 @@
 # Breaking Changes
 
+## 0.0.222
+
+### `--max-complexity` has been removed from the CLI ([#1877](https://github.com/charliermarsh/ruff/pull/1877))
+
+The McCabe plugin's `--max-complexity` setting has been removed from the CLI, for consistency with
+the treatment of other, similar settings.
+
+To set the maximum complexity, use the `max-complexity` property in your `pyproject.toml` file,
+like so:
+
+```toml
+[tool.ruff.mccabe]
+max-complexity = 10
+```
+
 ## 0.0.181
 
 ### Files excluded by `.gitignore` are now ignored ([#1234](https://github.com/charliermarsh/ruff/pull/1234))

CONTRIBUTING.md

@@ -56,33 +56,36 @@ 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 struct in `src/violations.rs` (e.g., `ModuleImportNotAtTopOfFile`).
+2. Map the violation struct to a rule 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.
 
-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
-violations and non-violations designed to evaluate and demonstrate the behavior of your lint rule.
+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/[origin]`, named to match
+the code you defined earlier (e.g., `resources/test/fixtures/pycodestyle/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/[origin]/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`.
 

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 = "0.0.222-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"
@@ -1364,10 +1365,31 @@ dependencies = [
 ]
 
 [[package]]
-name = "once_cell"
-version = "1.16.0"
+name = "num_enum"
+version = "0.5.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86f0b0d4bf799edbc74508c1e8bf170ff5f41238e5f8225603ca7caaae2b7860"
+checksum = "cf5395665662ef45796a4ff5486c5d41d29e0c09640af4c5f17fd94ee2c119c9"
+dependencies = [
+ "num_enum_derive",
+]
+
+[[package]]
+name = "num_enum_derive"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b0498641e53dd6ac1a4f22547548caa6864cc4933784319cd1775271c5a46ce"
+dependencies = [
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f61fba1741ea2b3d6a1e3178721804bb716a68a6aeba1149b5d52e3d464ea66"
 
 [[package]]
 name = "oorandom"
@@ -1620,6 +1642,17 @@ dependencies = [
  "termtree",
 ]
 
+[[package]]
+name = "proc-macro-crate"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eda0fc3b0fb7c975631757e14d9049da17374063edb6ebbcbc54d880d4fe94e9"
+dependencies = [
+ "once_cell",
+ "thiserror",
+ "toml",
+]
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -1873,27 +1906,19 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.222"
 dependencies = [
- "annotate-snippets 0.9.1",
  "anyhow",
- "assert_cmd",
- "atty",
- "bincode",
  "bitflags",
- "cachedir",
  "cfg-if 1.0.0",
  "chrono",
  "clap 4.0.32",
- "clap_complete_command",
- "clearscreen",
  "colored",
  "console_error_panic_hook",
  "console_log",
  "criterion",
  "dirs 4.0.0",
  "fern",
- "filetime",
  "getrandom 0.2.8",
  "glob",
  "globset",
@@ -1905,13 +1930,10 @@ dependencies = [
  "log",
  "natord",
  "nohash-hasher",
- "notify",
  "num-bigint",
  "num-traits",
  "once_cell",
  "path-absolutize",
- "quick-junit",
- "rayon",
  "regex",
  "ropey",
  "ruff_macros",
@@ -1923,33 +1945,65 @@ dependencies = [
  "semver",
  "serde",
  "serde-wasm-bindgen",
- "serde_json",
  "shellexpand",
- "similar",
  "strum",
  "strum_macros",
  "test-case",
  "textwrap",
  "titlecase",
- "toml",
- "update-informer",
- "ureq",
- "walkdir",
+ "toml_edit",
  "wasm-bindgen",
  "wasm-bindgen-test",
 ]
 
+[[package]]
+name = "ruff_cli"
+version = "0.0.222"
+dependencies = [
+ "annotate-snippets 0.9.1",
+ "anyhow",
+ "assert_cmd",
+ "atty",
+ "bincode",
+ "cachedir",
+ "chrono",
+ "clap 4.0.32",
+ "clap_complete_command",
+ "clearscreen",
+ "colored",
+ "filetime",
+ "glob",
+ "ignore",
+ "itertools",
+ "log",
+ "notify",
+ "path-absolutize",
+ "quick-junit",
+ "rayon",
+ "regex",
+ "ruff",
+ "rustc-hash",
+ "serde",
+ "serde_json",
+ "similar",
+ "strum",
+ "textwrap",
+ "update-informer",
+ "ureq",
+ "walkdir",
+]
+
 [[package]]
 name = "ruff_dev"
-version = "0.0.211"
+version = "0.0.222"
 dependencies = [
  "anyhow",
  "clap 4.0.32",
- "codegen",
  "itertools",
  "libcst",
  "once_cell",
  "ruff",
+ "ruff_cli",
  "rustpython-ast",
  "rustpython-common",
  "rustpython-parser",
@@ -1962,8 +2016,9 @@ dependencies = [
 
 [[package]]
 name = "ruff_macros"
-version = "0.0.211"
+version = "0.0.222"
 dependencies = [
+ "once_cell",
  "proc-macro2",
  "quote",
  "syn",
@@ -2004,8 +2059,8 @@ dependencies = [
 
 [[package]]
 name = "rustpython-ast"
-version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+version = "0.2.0"
+source = "git+https://github.com/RustPython/RustPython.git?rev=acbc517b55406c76da83d7b2711941d8d3f65b87#acbc517b55406c76da83d7b2711941d8d3f65b87"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -2014,8 +2069,8 @@ dependencies = [
 
 [[package]]
 name = "rustpython-common"
-version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+version = "0.2.0"
+source = "git+https://github.com/RustPython/RustPython.git?rev=acbc517b55406c76da83d7b2711941d8d3f65b87#acbc517b55406c76da83d7b2711941d8d3f65b87"
 dependencies = [
  "ascii",
  "bitflags",
@@ -2039,8 +2094,8 @@ dependencies = [
 
 [[package]]
 name = "rustpython-compiler-core"
-version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+version = "0.2.0"
+source = "git+https://github.com/RustPython/RustPython.git?rev=acbc517b55406c76da83d7b2711941d8d3f65b87#acbc517b55406c76da83d7b2711941d8d3f65b87"
 dependencies = [
  "bincode",
  "bitflags",
@@ -2049,15 +2104,15 @@ dependencies = [
  "lz4_flex",
  "num-bigint",
  "num-complex",
+ "num_enum",
  "serde",
- "static_assertions",
  "thiserror",
 ]
 
 [[package]]
 name = "rustpython-parser"
-version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=4d53c7cb27c0379adf8b51c4d3d0d2174f41d590#4d53c7cb27c0379adf8b51c4d3d0d2174f41d590"
+version = "0.2.0"
+source = "git+https://github.com/RustPython/RustPython.git?rev=acbc517b55406c76da83d7b2711941d8d3f65b87#acbc517b55406c76da83d7b2711941d8d3f65b87"
 dependencies = [
  "ahash",
  "anyhow",
@@ -2504,6 +2559,28 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "toml_datetime"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+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"

Cargo.toml

@@ -2,11 +2,13 @@
 members = [
   "flake8_to_ruff",
   "ruff_dev",
+  "ruff_cli",
 ]
+default-members = [".", "ruff_cli"]
 
 [package]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.222"
 authors = ["Charlie Marsh <charlie.r.marsh@gmail.com>"]
 edition = "2021"
 rust-version = "1.65.0"
@@ -19,22 +21,17 @@ license = "MIT"
 [lib]
 name = "ruff"
 crate-type = ["cdylib", "rlib"]
+doctest = false
 
 [dependencies]
-annotate-snippets = { version = "0.9.1", features = ["color"] }
 anyhow = { version = "1.0.66" }
-atty = { version = "0.2.14" }
-bincode = { version = "1.3.3" }
 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_complete_command = { version = "0.4.0" }
+clap = { version = "4.0.1", features = ["derive", "env"] }
 colored = { version = "2.0.0" }
 dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
-filetime = { version = "0.2.17" }
 glob = { version = "0.3.0" }
 globset = { version = "0.4.9" }
 ignore = { version = "0.4.18" }
@@ -43,36 +40,26 @@ libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a87
 log = { version = "0.4.17" }
 natord = { version = "1.0.9" }
 nohash-hasher = { version = "0.2.0" }
-notify = { version = "5.0.0" }
 num-bigint = { version = "0.4.3" }
 num-traits = "0.2.15"
 once_cell = { version = "1.16.0" }
 path-absolutize = { version = "3.0.14", features = ["once_cell_cache", "use_unix_paths_on_wasm"] }
-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 = "0.0.222", 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 = "acbc517b55406c76da83d7b2711941d8d3f65b87" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "acbc517b55406c76da83d7b2711941d8d3f65b87" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "acbc517b55406c76da83d7b2711941d8d3f65b87" }
 schemars = { version = "0.8.11" }
 semver = { version = "1.0.16" }
 serde = { version = "1.0.147", features = ["derive"] }
-serde_json = { version = "1.0.87" }
 shellexpand = { version = "3.0.0" }
-similar = { version = "2.2.1" }
 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" }
-walkdir = { version = "2.3.2" }
-
-[target.'cfg(not(target_family = "wasm"))'.dependencies]
-clearscreen = { version = "2.0.0" }
-rayon = { version = "1.5.3" }
-update-informer = { version = "0.6.0", default-features = false, features = ["pypi"], optional = true }
+toml_edit = { version = "0.17.1", features = ["easy"] }
 
 # https://docs.rs/getrandom/0.2.7/getrandom/#webassembly-support
 # For (future) wasm-pack support
@@ -87,17 +74,11 @@ wasm-bindgen = { version = "0.2.83" }
 [dev-dependencies]
 insta = { version = "1.19.1", features = ["yaml"] }
 test-case = { version = "2.2.2" }
-ureq = { version = "2.5.0", features = [] }
 wasm-bindgen-test = { version = "0.3.33" }
 
 [target.'cfg(not(target_family = "wasm"))'.dev-dependencies]
-assert_cmd = { version = "2.0.4" }
 criterion = { version = "0.4.0" }
 
-[features]
-default = ["update-informer"]
-update-informer = ["dep:update-informer"]
-
 [profile.release]
 panic = "abort"
 lto = "thin"

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"
 }

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"
+}

flake8_to_ruff/Cargo.lock

@@ -771,7 +771,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8_to_ruff"
-version = "0.0.211"
+version = "0.0.222"
 dependencies = [
  "anyhow",
  "clap",
@@ -1975,7 +1975,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.222"
 dependencies = [
  "anyhow",
  "bincode",

flake8_to_ruff/Cargo.toml

@@ -1,14 +1,12 @@
 [package]
 name = "flake8-to-ruff"
-version = "0.0.211-dev.0"
+version = "0.0.222-dev.0"
 edition = "2021"
 
-[lib]
-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 +16,7 @@ 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]
 

flake8_to_ruff/README.md

@@ -84,7 +84,7 @@ flake8-to-ruff path/to/.flake8 --plugin flake8-builtins --plugin flake8-quotes
 1. Ruff only supports a subset of the Flake configuration options. `flake8-to-ruff` will warn on and
    ignore unsupported options in the `.flake8` file (or equivalent). (Similarly, Ruff has a few
    configuration options that don't exist in Flake8.)
-2. Ruff will omit any error codes that are unimplemented or unsupported by Ruff, including error
+2. Ruff will omit any rule codes that are unimplemented or unsupported by Ruff, including rule
    codes from unsupported plugins. (See the [Ruff README](https://github.com/charliermarsh/ruff#user-content-how-does-ruff-compare-to-flake8)
    for the complete list of supported plugins.)
 

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

flake8_to_ruff/src/lib.rs

@@ -1,17 +0,0 @@
-#![allow(
-    clippy::collapsible_else_if,
-    clippy::collapsible_if,
-    clippy::implicit_hasher,
-    clippy::match_same_arms,
-    clippy::missing_errors_doc,
-    clippy::missing_panics_doc,
-    clippy::module_name_repetitions,
-    clippy::must_use_candidate,
-    clippy::similar_names,
-    clippy::too_many_lines
-)]
-
-pub mod black;
-pub mod converter;
-mod parser;
-pub mod plugin;

flake8_to_ruff/src/main.rs

@@ -1,4 +1,4 @@
-//! Utility to generate Ruff's pyproject.toml section from a Flake8 INI file.
+//! Utility to generate Ruff's `pyproject.toml` section from a Flake8 INI file.
 #![allow(
     clippy::collapsible_else_if,
     clippy::collapsible_if,
@@ -11,15 +11,14 @@
     clippy::similar_names,
     clippy::too_many_lines
 )]
+#![forbid(unsafe_code)]
 
 use std::path::PathBuf;
 
 use anyhow::Result;
 use clap::Parser;
 use configparser::ini::Ini;
-use flake8_to_ruff::black::parse_black_options;
-use flake8_to_ruff::converter;
-use flake8_to_ruff::plugin::Plugin;
+use ruff::flake8_to_ruff;
 
 #[derive(Parser)]
 #[command(
@@ -37,7 +36,7 @@ struct Cli {
     pyproject: Option<PathBuf>,
     /// List of plugins to enable.
     #[arg(long, value_delimiter = ',')]
-    plugin: Option<Vec<Plugin>>,
+    plugin: Option<Vec<flake8_to_ruff::Plugin>>,
 }
 
 fn main() -> Result<()> {
@@ -51,13 +50,13 @@ fn main() -> Result<()> {
     // Read the pyproject.toml file.
     let black = cli
         .pyproject
-        .map(parse_black_options)
+        .map(flake8_to_ruff::parse_black_options)
         .transpose()?
         .flatten();
 
     // Create Ruff's pyproject.toml section.
-    let pyproject = converter::convert(&config, black.as_ref(), cli.plugin)?;
-    println!("{}", toml::to_string_pretty(&pyproject)?);
+    let pyproject = flake8_to_ruff::convert(&config, black.as_ref(), cli.plugin)?;
+    println!("{}", toml_edit::easy::to_string_pretty(&pyproject)?);
 
     Ok(())
 }

playground/src/Editor/Editor.tsx

@@ -1,6 +1,11 @@
 import { useCallback, useEffect, useState } from "react";
 import { DEFAULT_PYTHON_SOURCE } from "../constants";
-import init, { check, Check, currentVersion, defaultSettings } from "../pkg";
+import init, {
+  check,
+  Diagnostic,
+  currentVersion,
+  defaultSettings,
+} from "../pkg";
 import { ErrorMessage } from "./ErrorMessage";
 import Header from "./Header";
 import { useTheme } from "./theme";
@@ -18,7 +23,7 @@ export default function Editor() {
   const [edit, setEdit] = useState<number>(0);
   const [settingsSource, setSettingsSource] = useState<string | null>(null);
   const [pythonSource, setPythonSource] = useState<string | null>(null);
-  const [checks, setChecks] = useState<Check[]>([]);
+  const [diagnostics, setDiagnostics] = useState<Diagnostic[]>([]);
   const [error, setError] = useState<string | null>(null);
   const [theme, setTheme] = useTheme();
 
@@ -32,25 +37,25 @@ export default function Editor() {
     }
 
     let config: any;
-    let checks: Check[];
+    let diagnostics: Diagnostic[];
 
     try {
       config = JSON.parse(settingsSource);
     } catch (e) {
-      setChecks([]);
+      setDiagnostics([]);
       setError((e as Error).message);
       return;
     }
 
     try {
-      checks = check(pythonSource, config);
+      diagnostics = check(pythonSource, config);
     } catch (e) {
       setError(e as string);
       return;
     }
 
     setError(null);
-    setChecks(checks);
+    setDiagnostics(diagnostics);
   }, [initialized, settingsSource, pythonSource]);
 
   useEffect(() => {
@@ -122,7 +127,7 @@ export default function Editor() {
               visible={tab === "Source"}
               source={pythonSource}
               theme={theme}
-              checks={checks}
+              diagnostics={diagnostics}
               onChange={handlePythonSourceChange}
             />
             <SettingsEditor

playground/src/Editor/SourceEditor.tsx

@@ -5,19 +5,19 @@
 import Editor, { useMonaco } from "@monaco-editor/react";
 import { MarkerSeverity, MarkerTag } from "monaco-editor";
 import { useCallback, useEffect } from "react";
-import { Check } from "../pkg";
+import { Diagnostic } from "../pkg";
 import { Theme } from "./theme";
 
 export default function SourceEditor({
   visible,
   source,
   theme,
-  checks,
+  diagnostics,
   onChange,
 }: {
   visible: boolean;
   source: string;
-  checks: Check[];
+  diagnostics: Diagnostic[];
   theme: Theme;
   onChange: (pythonSource: string) => void;
 }) {
@@ -33,15 +33,15 @@ export default function SourceEditor({
     editor.setModelMarkers(
       model,
       "owner",
-      checks.map((check) => ({
-        startLineNumber: check.location.row,
-        startColumn: check.location.column + 1,
-        endLineNumber: check.end_location.row,
-        endColumn: check.end_location.column + 1,
-        message: `${check.code}: ${check.message}`,
+      diagnostics.map((diagnostic) => ({
+        startLineNumber: diagnostic.location.row,
+        startColumn: diagnostic.location.column + 1,
+        endLineNumber: diagnostic.end_location.row,
+        endColumn: diagnostic.end_location.column + 1,
+        message: `${diagnostic.code}: ${diagnostic.message}`,
         severity: MarkerSeverity.Error,
         tags:
-          check.code === "F401" || check.code === "F841"
+          diagnostic.code === "F401" || diagnostic.code === "F841"
             ? [MarkerTag.Unnecessary]
             : [],
       })),
@@ -52,7 +52,7 @@ export default function SourceEditor({
       {
         // @ts-expect-error: The type definition is wrong.
         provideCodeActions: function (model, position) {
-          const actions = checks
+          const actions = diagnostics
             .filter((check) => position.startLineNumber === check.location.row)
             .filter((check) => check.fix)
             .map((check) => ({
@@ -89,7 +89,7 @@ export default function SourceEditor({
     return () => {
       codeActionProvider?.dispose();
     };
-  }, [checks, monaco]);
+  }, [diagnostics, monaco]);
 
   const handleChange = useCallback(
     (value: string | undefined) => {

pyproject.toml

@@ -1,10 +1,13 @@
 [build-system]
-requires = ["maturin>=0.14,<0.15"]
+requires = ["maturin>=0.14.10,<0.15"]
+# We depend on >=0.14.10 because we specify name in
+# [package.metadata.maturin] in ruff_cli/Cargo.toml.
+
 build-backend = "maturin"
 
 [project]
 name = "ruff"
-version = "0.0.211"
+version = "0.0.222"
 description = "An extremely fast Python linter, written in Rust."
 authors = [
   { name = "Charlie Marsh", email = "charlie.r.marsh@gmail.com" },
@@ -35,6 +38,8 @@ urls = { repository = "https://github.com/charliermarsh/ruff" }
 
 [tool.maturin]
 bindings = "bin"
+manifest-path = "ruff_cli/Cargo.toml"
+python-source = "python"
 strip = true
 
 [tool.setuptools]

resources/test/fixtures/flake8_annotations/allow_nested_overload.py

@@ -0,0 +1,9 @@
+class C:
+    from typing import overload
+
+    @overload
+    def f(self, x: int, y: int) -> None:
+        ...
+
+    def f(self, x, y):
+        pass

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)

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)

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)

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)

resources/test/fixtures/flake8_bandit/S508.py

@@ -0,0 +1,6 @@
+from pysnmp.hlapi import CommunityData
+
+CommunityData("public", mpModel=0)  # S508
+CommunityData("public", mpModel=1)  # S508
+
+CommunityData("public", mpModel=2)  # OK

resources/test/fixtures/flake8_bandit/S509.py

@@ -0,0 +1,7 @@
+from pysnmp.hlapi import UsmUserData
+
+
+insecure = UsmUserData("securityName")  # S509
+auth_no_priv = UsmUserData("securityName", "authName")  # S509
+
+less_insecure = UsmUserData("securityName", "authName", "privName")  # OK

resources/test/fixtures/flake8_bandit/S701.py

@@ -0,0 +1,29 @@
+import jinja2
+from jinja2 import Environment, select_autoescape
+templateLoader = jinja2.FileSystemLoader( searchpath="/" )
+something = ''
+
+Environment(loader=templateLoader, load=templateLoader, autoescape=True)
+templateEnv = jinja2.Environment(autoescape=True,
+        loader=templateLoader )
+Environment(loader=templateLoader, load=templateLoader, autoescape=something)  # S701
+templateEnv = jinja2.Environment(autoescape=False, loader=templateLoader )  # S701
+Environment(loader=templateLoader,
+            load=templateLoader,
+            autoescape=False)  # S701
+
+Environment(loader=templateLoader,  # S701
+            load=templateLoader)
+
+Environment(loader=templateLoader, autoescape=select_autoescape())
+
+Environment(loader=templateLoader,
+            autoescape=select_autoescape(['html', 'htm', 'xml']))
+
+Environment(loader=templateLoader,
+            autoescape=jinja2.select_autoescape(['html', 'htm', 'xml']))
+
+
+def fake_func():
+    return 'foobar'
+Environment(loader=templateLoader, autoescape=fake_func())  # S701

resources/test/fixtures/flake8_bugbear/B023.py

@@ -25,10 +25,10 @@ for x in range(3):
 
 
 def check_inside_functions_too():
-    ls = [lambda: x for x in range(2)]
-    st = {lambda: x for x in range(2)}
-    gn = (lambda: x for x in range(2))
-    dt = {x: lambda: x for x in range(2)}
+    ls = [lambda: x for x in range(2)]  # error
+    st = {lambda: x for x in range(2)}  # error
+    gn = (lambda: x for x in range(2))  # error
+    dt = {x: lambda: x for x in range(2)}  # error
 
 
 async def pointless_async_iterable():
@@ -37,9 +37,9 @@ async def pointless_async_iterable():
 
 async def container_for_problems():
     async for x in pointless_async_iterable():
-        functions.append(lambda: x)
+        functions.append(lambda: x)  # error
 
-    [lambda: x async for x in pointless_async_iterable()]
+    [lambda: x async for x in pointless_async_iterable()]  # error
 
 
 a = 10
@@ -47,10 +47,10 @@ b = 0
 while True:
     a = a_ = a - 1
     b += 1
-    functions.append(lambda: a)
-    functions.append(lambda: a_)
-    functions.append(lambda: b)
-    functions.append(lambda: c)  # not a name error because of late binding!
+    functions.append(lambda: a)  # error
+    functions.append(lambda: a_)  # error
+    functions.append(lambda: b)  # error
+    functions.append(lambda: c)  # error, but not a name error due to late binding
     c: bool = a > 3
     if not c:
         break
@@ -58,7 +58,7 @@ while True:
 # Nested loops should not duplicate reports
 for j in range(2):
     for k in range(3):
-        lambda: j * k
+        lambda: j * k  # error
 
 
 for j, k, l in [(1, 2, 3)]:
@@ -80,3 +80,95 @@ for var in range(2):
 
 for i in range(3):
     lambda: f"{i}"
+
+
+# `query` is defined in the function, so also defining it in the loop should be OK.
+for name in ["a", "b"]:
+    query = name
+
+    def myfunc(x):
+        query = x
+        query_post = x
+        _ = query
+        _ = query_post
+
+    query_post = name  # in case iteration order matters
+
+
+# Bug here because two dict comprehensions reference `name`, one of which is inside
+# the lambda.  This should be totally fine, of course.
+_ = {
+    k: v
+    for k, v in reduce(
+        lambda data, event: merge_mappings(
+            [data, {name: f(caches, data, event) for name, f in xx}]
+        ),
+        events,
+        {name: getattr(group, name) for name in yy},
+    ).items()
+    if k in backfill_fields
+}
+
+
+# OK to define lambdas if they're immediately consumed, typically as the `key=`
+# argument or in a consumed `filter()` (even if a comprehension is better style)
+for x in range(2):
+    # It's not a complete get-out-of-linting-free construct - these should fail:
+    min([None, lambda: x], key=repr)
+    sorted([None, lambda: x], key=repr)
+    any(filter(bool, [None, lambda: x]))
+    list(filter(bool, [None, lambda: x]))
+    all(reduce(bool, [None, lambda: x]))
+
+    # But all these should be OK:
+    min(range(3), key=lambda y: x * y)
+    max(range(3), key=lambda y: x * y)
+    sorted(range(3), key=lambda y: x * y)
+
+    any(map(lambda y: x < y, range(3)))
+    all(map(lambda y: x < y, range(3)))
+    set(map(lambda y: x < y, range(3)))
+    list(map(lambda y: x < y, range(3)))
+    tuple(map(lambda y: x < y, range(3)))
+    sorted(map(lambda y: x < y, range(3)))
+    frozenset(map(lambda y: x < y, range(3)))
+
+    any(filter(lambda y: x < y, range(3)))
+    all(filter(lambda y: x < y, range(3)))
+    set(filter(lambda y: x < y, range(3)))
+    list(filter(lambda y: x < y, range(3)))
+    tuple(filter(lambda y: x < y, range(3)))
+    sorted(filter(lambda y: x < y, range(3)))
+    frozenset(filter(lambda y: x < y, range(3)))
+
+    any(reduce(lambda y: x | y, range(3)))
+    all(reduce(lambda y: x | y, range(3)))
+    set(reduce(lambda y: x | y, range(3)))
+    list(reduce(lambda y: x | y, range(3)))
+    tuple(reduce(lambda y: x | y, range(3)))
+    sorted(reduce(lambda y: x | y, range(3)))
+    frozenset(reduce(lambda y: x | y, range(3)))
+
+    import functools
+
+    any(functools.reduce(lambda y: x | y, range(3)))
+    all(functools.reduce(lambda y: x | y, range(3)))
+    set(functools.reduce(lambda y: x | y, range(3)))
+    list(functools.reduce(lambda y: x | y, range(3)))
+    tuple(functools.reduce(lambda y: x | y, range(3)))
+    sorted(functools.reduce(lambda y: x | y, range(3)))
+    frozenset(functools.reduce(lambda y: x | y, range(3)))
+
+# OK because the lambda which references a loop variable is defined in a `return`
+# statement, and after we return the loop variable can't be redefined.
+# In principle we could do something fancy with `break`, but it's not worth it.
+def iter_f(names):
+    for name in names:
+        if exists(name):
+            return lambda: name if exists(name) else None
+
+        if foo(name):
+            return [lambda: name]  # known false alarm
+
+        if False:
+            return [lambda: i for i in range(3)]  # error

resources/test/fixtures/flake8_bugbear/B024.py

@@ -1,15 +1,16 @@
 """
 Should emit:
-B024 - on lines 17, 34, 52, 58, 69, 74, 79, 84, 89
+B024 - on lines 18, 71, 82, 87, 92, 141
 """
 
 import abc
 import abc as notabc
 from abc import ABC, ABCMeta
-from abc import abstractmethod
+from abc import abstractmethod, abstractproperty
 from abc import abstractmethod as abstract
 from abc import abstractmethod as abstractaoeuaoeuaoeu
 from abc import abstractmethod as notabstract
+from abc import abstractproperty as notabstract_property
 
 import foo
 
@@ -49,12 +50,24 @@ class Base_6(ABC):
         foo()
 
 
-class Base_7(ABC):  # error
+class Base_7(ABC):
     @notabstract
     def method(self):
         foo()
 
 
+class Base_8(ABC):
+    @notabstract_property
+    def method(self):
+        foo()
+
+
+class Base_9(ABC):
+    @abstractproperty
+    def method(self):
+        foo()
+
+
 class MetaBase_1(metaclass=ABCMeta):  # error
     def method(self):
         foo()

resources/test/fixtures/flake8_bugbear/B027.py

@@ -1,11 +1,12 @@
 """
 Should emit:
-B027 - on lines 12, 15, 18, 22, 30
+B027 - on lines 13, 16, 19, 23
 """
 import abc
 from abc import ABC
-from abc import abstractmethod
+from abc import abstractmethod, abstractproperty
 from abc import abstractmethod as notabstract
+from abc import abstractproperty as notabstract_property
 
 
 class AbstractClass(ABC):
@@ -42,6 +43,18 @@ class AbstractClass(ABC):
     def abstract_3(self):
         ...
 
+    @abc.abstractproperty
+    def abstract_4(self):
+        ...
+
+    @abstractproperty
+    def abstract_5(self):
+        ...
+
+    @notabstract_property
+    def abstract_6(self):
+        ...
+
     def body_1(self):
         print("foo")
         ...

resources/test/fixtures/flake8_comprehensions/C400.py

@@ -2,3 +2,10 @@ x = list(x for x in range(3))
 x = list(
     x for x in range(3)
 )
+
+
+def list(*args, **kwargs):
+    return None
+
+
+list(x for x in range(3))

resources/test/fixtures/flake8_comprehensions/C401.py

@@ -2,3 +2,10 @@ x = set(x for x in range(3))
 x = set(
     x for x in range(3)
 )
+
+
+def set(*args, **kwargs):
+    return None
+
+
+set(x for x in range(3))

resources/test/fixtures/flake8_comprehensions/C405.py

@@ -1,5 +1,18 @@
-s1 = set([1, 2])
-s2 = set((1, 2))
-s3 = set([])
-s4 = set(())
-s5 = set()
+set([1, 2])
+set((1, 2))
+set([])
+set(())
+set()
+set((1,))
+set((
+    1,
+))
+set([
+    1,
+])
+set(
+    (1,)
+)
+set(
+    [1,]
+)

resources/test/fixtures/flake8_comprehensions/C408.py

@@ -3,3 +3,10 @@ l = list()
 d1 = dict()
 d2 = dict(a=1)
 d3 = dict(**d2)
+
+
+def list():
+    return [1, 2, 3]
+
+
+a = list()

resources/test/fixtures/flake8_comprehensions/C413.py

@@ -4,3 +4,10 @@ list(sorted(x))
 reversed(sorted(x))
 reversed(sorted(x, key=lambda e: e))
 reversed(sorted(x, reverse=True))
+
+
+def reversed(*args, **kwargs):
+    return None
+
+
+reversed(sorted(x, reverse=True))

resources/test/fixtures/flake8_pie/PIE794.py

@@ -31,3 +31,10 @@ class User(BaseModel):
     @buzz.setter
     def buzz(self, value: str | int) -> None:
         ...
+
+
+class User:
+    bar: str = StringField()
+    foo: bool = BooleanField()
+    # ...
+    bar = StringField()  # PIE794

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

resources/test/fixtures/flake8_quotes/docstring_doubles_function.py

@@ -17,6 +17,15 @@ def fun_with_params_no_docstring(a, b="""
 """ """docstring"""):
     pass
 
+
 def fun_with_params_no_docstring2(a, b=c[foo():], c=\
     """ not a docstring """):
     pass
+
+
+def function_with_single_docstring(a):
+    "Single line docstring"
+
+
+def double_inside_single(a):
+    'Double inside "single "'

resources/test/fixtures/flake8_quotes/docstring_singles_function.py

@@ -13,11 +13,19 @@ def foo2():
 
 
 def fun_with_params_no_docstring(a, b='''
-    not a 
+    not a
 ''' '''docstring'''):
     pass
 
+
 def fun_with_params_no_docstring2(a, b=c[foo():], c=\
     ''' not a docstring '''):
     pass
 
+
+def function_with_single_docstring(a):
+    'Single line docstring'
+
+
+def double_inside_single(a):
+    "Double inside 'single '"

resources/test/fixtures/flake8_quotes/doubles_escaped.py

@@ -1,4 +1,5 @@
 this_should_raise_Q003 = 'This is a \'string\''
+this_should_raise_Q003 = 'This is \\ a \\\'string\''
 this_is_fine = '"This" is a \'string\''
 this_is_fine = "This is a 'string'"
 this_is_fine = "\"This\" is a 'string'"

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

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

resources/test/fixtures/flake8_simplify/SIM108.py

@@ -0,0 +1,93 @@
+# SIM108
+if a:
+    b = c
+else:
+    b = d
+
+# OK
+b = c if a else d
+
+# OK
+if a:
+    b = c
+elif c:
+    b = a
+else:
+    b = d
+
+# OK
+if True:
+    pass
+elif a:
+    b = 1
+else:
+    b = 2
+
+# OK (false negative)
+if True:
+    pass
+else:
+    if a:
+        b = 1
+    else:
+        b = 2
+
+
+import sys
+
+# OK
+if sys.version_info >= (3, 9):
+    randbytes = random.randbytes
+else:
+    randbytes = _get_random_bytes
+
+# OK
+if sys.platform == "darwin":
+    randbytes = random.randbytes
+else:
+    randbytes = _get_random_bytes
+
+# OK
+if sys.platform.startswith("linux"):
+    randbytes = random.randbytes
+else:
+    randbytes = _get_random_bytes
+
+
+# OK (includes comments)
+if x > 0:
+    # test test
+    abc = x
+else:
+    # test test test
+    abc = -x
+
+
+# OK (too long)
+if parser.errno == BAD_FIRST_LINE:
+    req = wrappers.Request(sock, server=self._server)
+else:
+    req = wrappers.Request(
+        sock,
+        parser.get_method(),
+        parser.get_scheme() or _scheme,
+        parser.get_path(),
+        parser.get_version(),
+        parser.get_query_string(),
+        server=self._server,
+    )
+
+
+# SIM108
+if a:
+    b = cccccccccccccccccccccccccccccccccccc
+else:
+    b = ddddddddddddddddddddddddddddddddddddd
+
+
+# OK (too long)
+if True:
+    if a:
+        b = cccccccccccccccccccccccccccccccccccc
+    else:
+        b = ddddddddddddddddddddddddddddddddddddd

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

resources/test/fixtures/flake8_simplify/SIM110.py

@@ -1,5 +1,6 @@
 def f():
-    for x in iterable:  # SIM110
+    # SIM110
+    for x in iterable:
         if check(x):
             return True
     return False
@@ -20,14 +21,16 @@ def f():
 
 
 def f():
-    for x in iterable:  # SIM111
+    # SIM111
+    for x in iterable:
         if check(x):
             return False
     return True
 
 
 def f():
-    for x in iterable:  # SIM111
+    # SIM111
+    for x in iterable:
         if not x.is_empty():
             return False
     return True
@@ -45,3 +48,70 @@ def f():
         if check(x):
             return "foo"
     return "bar"
+
+
+def f():
+    # SIM110
+    for x in iterable:
+        if check(x):
+            return True
+    else:
+        return False
+
+
+def f():
+    # SIM111
+    for x in iterable:
+        if check(x):
+            return False
+    else:
+        return True
+
+
+def f():
+    # SIM110
+    for x in iterable:
+        if check(x):
+            return True
+    else:
+        return False
+    return True
+
+
+def f():
+    # SIM111
+    for x in iterable:
+        if check(x):
+            return False
+    else:
+        return True
+    return False
+
+
+def f():
+    for x in iterable:
+        if check(x):
+            return True
+        elif x.is_empty():
+            return True
+    return False
+
+
+def f():
+    for x in iterable:
+        if check(x):
+            return True
+        else:
+            return True
+    return False
+
+
+def f():
+    for x in iterable:
+        if check(x):
+            return True
+        elif x.is_empty():
+            return True
+    else:
+        return True
+    return False

resources/test/fixtures/flake8_simplify/SIM111.py

@@ -1,10 +1,18 @@
 def f():
-    for x in iterable:  # SIM110
+    # SIM110
+    for x in iterable:
         if check(x):
             return True
     return False
 
 
+def f():
+    for x in iterable:
+        if check(x):
+            return True
+    return True
+
+
 def f():
     for el in [1, 2, 3]:
         if is_true(el):
@@ -13,21 +21,97 @@ def f():
 
 
 def f():
-    for x in iterable:  # SIM111
+    # SIM111
+    for x in iterable:
         if check(x):
             return False
     return True
 
 
 def f():
-    for x in iterable:  # SIM 111
+    # SIM111
+    for x in iterable:
         if not x.is_empty():
             return False
     return True
 
 
+def f():
+    for x in iterable:
+        if check(x):
+            return False
+    return False
+
+
 def f():
     for x in iterable:
         if check(x):
             return "foo"
     return "bar"
+
+
+def f():
+    # SIM110
+    for x in iterable:
+        if check(x):
+            return True
+    else:
+        return False
+
+
+def f():
+    # SIM111
+    for x in iterable:
+        if check(x):
+            return False
+    else:
+        return True
+
+
+def f():
+    # SIM110
+    for x in iterable:
+        if check(x):
+            return True
+    else:
+        return False
+    return True
+
+
+def f():
+    # SIM111
+    for x in iterable:
+        if check(x):
+            return False
+    else:
+        return True
+    return False
+
+
+def f():
+    for x in iterable:
+        if check(x):
+            return True
+        elif x.is_empty():
+            return True
+    return False
+
+
+def f():
+    for x in iterable:
+        if check(x):
+            return True
+        else:
+            return True
+    return False
+
+
+def f():
+    for x in iterable:
+        if check(x):
+            return True
+        elif x.is_empty():
+            return True
+    else:
+        return True
+    return False

resources/test/fixtures/flake8_simplify/SIM112.py

@@ -0,0 +1,19 @@
+import os
+
+# Bad
+os.environ['foo']
+
+os.environ.get('foo')
+
+os.environ.get('foo', 'bar')
+
+os.getenv('foo')
+
+# Good
+os.environ['FOO']
+
+os.environ.get('FOO')
+
+os.environ.get('FOO', 'bar')
+
+os.getenv('FOO')

resources/test/fixtures/flake8_simplify/SIM115.py

@@ -0,0 +1,6 @@
+f = open('foo.txt')  # SIM115
+data = f.read()
+f.close()
+
+with open('foo.txt') as f:  # OK
+    data = f.read()

resources/test/fixtures/flake8_simplify/SIM117.py

@@ -2,6 +2,11 @@ with A() as a:  # SIM117
     with B() as b:
         print("hello")
 
+with A():  # SIM117
+    with B():
+        with C():
+            print("hello")
+
 with A() as a:
     a()
     with B() as 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()

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

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

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

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

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

resources/test/fixtures/flake8_simplify/SIM401.py

@@ -0,0 +1,87 @@
+###
+# Positive cases
+###
+
+# SIM401 (pattern-1)
+if key in a_dict:
+    var = a_dict[key]
+else:
+    var = "default1"
+
+# SIM401 (pattern-2)
+if key not in a_dict:
+    var = "default2"
+else:
+    var = a_dict[key]
+
+# SIM401 (default with a complex expression)
+if key in a_dict:
+    var = a_dict[key]
+else:
+    var = val1 + val2
+
+# SIM401 (complex expression in key)
+if keys[idx] in a_dict:
+    var = a_dict[keys[idx]]
+else:
+    var = "default"
+
+# SIM401 (complex expression in dict)
+if key in dicts[idx]:
+    var = dicts[idx][key]
+else:
+    var = "default"
+
+# SIM401 (complex expression in var)
+if key in a_dict:
+    vars[idx] = a_dict[key]
+else:
+    vars[idx] = "default"
+
+###
+# Negative cases
+###
+
+# OK (false negative)
+if not key in a_dict:
+    var = "default"
+else:
+    var = a_dict[key]
+
+# OK (different dict)
+if key in a_dict:
+    var = other_dict[key]
+else:
+    var = "default"
+
+# OK (different key)
+if key in a_dict:
+    var = a_dict[other_key]
+else:
+    var = "default"
+
+# OK (different var)
+if key in a_dict:
+    var = a_dict[key]
+else:
+    other_var = "default"
+
+# OK (extra vars in body)
+if key in a_dict:
+    var = a_dict[key]
+    var2 = value2
+else:
+    var = "default"
+
+# OK (extra vars in orelse)
+if key in a_dict:
+    var = a_dict[key]
+else:
+    var2 = value2
+    var = "default"
+
+# OK (complex default value)
+if key in a_dict:
+    var = a_dict[key]
+else:
+    var = foo()

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).
     ###
@@ -153,3 +181,17 @@ def f(a: int, b: int) -> str:
 
 def f(a, b):
     return f"{a}{b}"
+
+
+###
+# Unused arguments on magic methods.
+###
+class C:
+    def __init__(self, x) -> None:
+        print("Hello, world!")
+
+    def __str__(self) -> str:
+        return "Hello, world!"
+
+    def __exit__(self, exc_type, exc_value, traceback) -> None:
+        print("Hello, world!")

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

resources/test/fixtures/isort/order_by_type_with_custom_classes.py

@@ -0,0 +1,4 @@
+from sklearn.svm import func, SVC, CONST, Klass
+from subprocess import N_CLASS, PIPE, Popen, STDOUT
+from module import CLASS, Class, CONSTANT, function, BASIC, Apple
+from torch.nn import SELU, AClass, A_CONSTANT

resources/test/fixtures/isort/relative_imports_order.py

@@ -0,0 +1,3 @@
+from ... import a
+from .. import b
+from . import c

resources/test/fixtures/isort/required_imports/comment.py

@@ -0,0 +1,3 @@
+#!/usr/bin/env python3
+
+x = 1

resources/test/fixtures/isort/required_imports/docstring.py

@@ -0,0 +1,3 @@
+"""Hello, world!"""
+
+x = 1

resources/test/fixtures/isort/required_imports/docstring_only.py

@@ -0,0 +1 @@
+"""Hello, world!"""

resources/test/fixtures/isort/required_imports/docstring_with_continuation.py

@@ -0,0 +1,2 @@
+"""Hello, world!"""; x = \
+    1; y = 2

resources/test/fixtures/isort/required_imports/docstring_with_semicolon.py

@@ -0,0 +1 @@
+"""Hello, world!"""; x = 1

resources/test/fixtures/isort/required_imports/existing_import.py

@@ -0,0 +1,2 @@
+from __future__ import generator_stop
+import os

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

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

resources/test/fixtures/pycodestyle/E999.py

@@ -1,2 +1,4 @@
+
 def x():
 
+

resources/test/fixtures/pycodestyle/W505.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+"""Here's a top-level docstring that's over the limit."""
+
+
+def f():
+    """Here's a docstring that's also over the limit."""
+
+    x = 1  # Here's a comment that's over the limit, but it's not standalone.
+
+    # Here's a standalone comment that's over the limit.
+
+    print("Here's a string that's over the limit, but it's not a docstring.")
+
+
+"This is also considered a docstring, and is over the limit."

resources/test/fixtures/pyflakes/F401_6.py

@@ -9,7 +9,6 @@ from .background import BackgroundTasks
 # F401 `datastructures.UploadFile` imported but unused
 from .datastructures import UploadFile as FileUpload
 
-
 # OK
 import applications as applications
 

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}

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}

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

resources/test/fixtures/pyflakes/builtins.py

@@ -0,0 +1 @@
+_("Translations")

resources/test/fixtures/pyflakes/typing_modules.py

@@ -0,0 +1,7 @@
+from typing import Union
+
+from airflow.typing_compat import Literal, Optional
+
+
+X = Union[Literal[False], Literal["db"]]
+y = Optional["Class"]

resources/test/fixtures/pygrep-hooks/PGH002_0.py

@@ -5,4 +5,3 @@ from warnings import warn
 warnings.warn("this is ok")
 warn("by itself is also ok")
 logging.warning("this is fine")
-log.warning("this is ok")

resources/test/fixtures/pygrep-hooks/PGH002_1.py

@@ -2,14 +2,4 @@ import logging
 from logging import warn
 
 logging.warn("this is not ok")
-log.warn("this is also not ok")
 warn("not ok")
-
-
-def foo():
-    from logging import warn
-
-    def warn():
-        pass
-
-    warn("has been redefined, but we will still report it")

resources/test/fixtures/pylint/constant_comparison.py

@@ -0,0 +1,59 @@
+"""Check that magic values are not used in comparisons"""
+
+if 100 == 100: # [comparison-of-constants]
+    pass
+
+if 1 == 3: # [comparison-of-constants]
+    pass
+
+if 1 != 3: # [comparison-of-constants]
+    pass
+
+x = 0
+if 4 == 3 == x: # [comparison-of-constants]
+    pass
+
+if x == 0: # correct
+    pass
+
+y = 1
+if x == y: # correct
+    pass
+
+if 1 > 0: # [comparison-of-constants]
+    pass
+
+if x > 0: # correct
+    pass
+
+if 1 >= 0: # [comparison-of-constants]
+    pass
+
+if x >= 0: # correct
+    pass
+
+if 1 < 0: # [comparison-of-constants]
+    pass
+
+if x < 0: # correct
+    pass
+
+if 1 <= 0: # [comparison-of-constants]
+    pass
+
+if x <= 0: # correct
+    pass
+
+word = "hello"
+if word == "": # correct
+    pass
+
+if "hello" == "": # [comparison-of-constants]
+    pass
+
+truthy = True
+if truthy == True: # correct
+    pass
+
+if True == False: # [comparison-of-constants]
+    pass

resources/test/fixtures/pylint/magic_value_comparison.py

@@ -0,0 +1,71 @@
+"""Check that magic values are not used in comparisons"""
+import cmath
+
+user_input = 10
+
+if 10 > user_input: # [magic-value-comparison]
+    pass
+
+if 10 == 100: # [comparison-of-constants] R0133
+    pass
+
+if 1 == 3: # [comparison-of-constants] R0133
+    pass
+
+x = 0
+if 4 == 3 == x: # [comparison-of-constants] R0133
+    pass
+
+time_delta = 7224
+ONE_HOUR = 3600
+
+if time_delta > ONE_HOUR: # correct
+    pass
+
+argc = 1
+
+if argc != -1: # correct
+    pass
+
+if argc != 0: # correct
+    pass
+
+if argc != 1: # correct
+    pass
+
+if argc != 2: # [magic-value-comparison]
+    pass
+
+if __name__ == "__main__": # correct
+    pass
+
+ADMIN_PASSWORD = "SUPERSECRET"
+input_password = "password"
+
+if input_password == "": # correct
+    pass
+
+if input_password == ADMIN_PASSWORD: # correct
+    pass
+
+if input_password == "Hunter2": # [magic-value-comparison]
+    pass
+
+PI = 3.141592653589793238
+pi_estimation = 3.14
+
+if pi_estimation == 3.141592653589793238: # [magic-value-comparison]
+    pass
+
+if pi_estimation == PI: # correct
+    pass
+
+HELLO_WORLD = b"Hello, World!"
+user_input = b"Hello, There!"
+
+if user_input == b"something": # [magic-value-comparison]
+    pass
+
+if user_input == HELLO_WORLD: # correct
+    pass
+

resources/test/fixtures/pyupgrade/UP024_3.py

@@ -0,0 +1,8 @@
+class SocketError(Exception):
+    pass
+
+
+try:
+    raise SocketError()
+except SocketError:
+    pass

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

resources/test/fixtures/pyupgrade/UP030_0.py

@@ -0,0 +1,36 @@
+# Invalid calls; errors expected.
+
+"{0}" "{1}" "{2}".format(1, 2, 3)
+
+"a {3} complicated {1} string with {0} {2}".format(
+    "first", "second", "third", "fourth"
+)
+
+'{0}'.format(1)
+
+'{0:x}'.format(30)
+
+x = '{0}'.format(1)
+
+'''{0}\n{1}\n'''.format(1, 2)
+
+x = "foo {0}" \
+    "bar {1}".format(1, 2)
+
+("{0}").format(1)
+
+"\N{snowman} {0}".format(1)
+
+'{' '0}'.format(1)
+
+# These will not change because we are waiting for libcst to fix this issue:
+# https://github.com/Instagram/LibCST/issues/846
+print(
+    'foo{0}'
+    'bar{1}'.format(1, 2)
+)
+
+print(
+    'foo{0}'  # ohai\n"
+    'bar{1}'.format(1, 2)
+)

resources/test/fixtures/pyupgrade/UP030_1.py

@@ -0,0 +1,23 @@
+# Valid calls; no errors expected.
+
+'{}'.format(1)
+
+
+x = ('{0} {1}',)
+
+'{0} {0}'.format(1)
+
+'{0:<{1}}'.format(1, 4)
+
+f"{0}".format(a)
+
+f"{0}".format(1)
+
+print(f"{0}".format(1))
+
+# I did not include the following tests because ruff does not seem to work with
+# invalid python syntax (which is a good thing)
+
+# "{0}"format(1)
+# '{'.format(1)", "'}'.format(1)
+# ("{0}" # {1}\n"{2}").format(1, 2, 3)

resources/test/project/README.md

@@ -17,7 +17,7 @@ resources/test/project/examples/docs/docs/file.py:8:5: F841 Local variable `x` i
 resources/test/project/project/file.py:1:8: F401 `os` imported but unused
 resources/test/project/project/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
 Found 7 error(s).
-6 potentially fixable with the --fix option.
+7 potentially fixable with the --fix option.
 ```
 
 Running from the project directory itself should exhibit the same behavior:
@@ -32,7 +32,7 @@ examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never
 project/file.py:1:8: F401 `os` imported but unused
 project/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
 Found 7 error(s).
-6 potentially fixable with the --fix option.
+7 potentially fixable with the --fix option.
 ```
 
 Running from the sub-package directory should exhibit the same behavior, but omit the top-level
@@ -43,7 +43,7 @@ files:
 docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
 docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
 Found 2 error(s).
-1 potentially fixable with the --fix option.
+2 potentially fixable with the --fix option.
 ```
 
 `--config` should force Ruff to use the specified `pyproject.toml` for all files, and resolve
@@ -74,7 +74,7 @@ docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
 docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
 excluded/script.py:5:5: F841 Local variable `x` is assigned to but never used
 Found 4 error(s).
-1 potentially fixable with the --fix option.
+4 potentially fixable with the --fix option.
 ```
 
 Passing an excluded directory directly should report errors in the contained files:

ruff_cli/Cargo.toml

@@ -0,0 +1,68 @@
+[package]
+name = "ruff_cli"
+version = "0.0.222"
+authors = ["Charlie Marsh <charlie.r.marsh@gmail.com>"]
+edition = "2021"
+rust-version = "1.65.0"
+documentation = "https://github.com/charliermarsh/ruff"
+homepage = "https://github.com/charliermarsh/ruff"
+repository = "https://github.com/charliermarsh/ruff"
+readme = "../README.md"
+license = "MIT"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[[bin]]
+name = "ruff"
+path = "src/main.rs"
+doctest = false
+
+# Since the name of the binary is the same as the name of the `ruff` crate
+# running `cargo doc --no-deps --all` results in an `output filename collision`
+# See also https://github.com/rust-lang/cargo/issues/6313.
+# We therefore disable the documentation generation for the binary.
+doc = false
+
+[dependencies]
+ruff = { path = ".." }
+
+annotate-snippets = { version = "0.9.1", features = ["color"] }
+anyhow = { version = "1.0.66" }
+atty = { version = "0.2.14" }
+bincode = { version = "1.3.3" }
+cachedir = { version = "0.3.0" }
+chrono = { version = "0.4.21", default-features = false, features = ["clock"] }
+clap = { version = "4.0.1", features = ["derive", "env"] }
+clap_complete_command = { version = "0.4.0" }
+clearscreen = { version = "2.0.0" }
+colored = { version = "2.0.0" }
+filetime = { version = "0.2.17" }
+glob = { version = "0.3.0" }
+ignore = { version = "0.4.18" }
+itertools = { version = "0.10.5" }
+log = { version = "0.4.17" }
+notify = { version = "5.0.0" }
+path-absolutize = { version = "3.0.14", features = ["once_cell_cache"] }
+quick-junit = { version = "0.3.2" }
+rayon = { version = "1.5.3" }
+regex = { version = "1.6.0" }
+rustc-hash = { version = "1.1.0" }
+serde = { version = "1.0.147", features = ["derive"] }
+serde_json = { version = "1.0.87" }
+similar = { version = "2.2.1" }
+textwrap = { version = "0.16.0" }
+update-informer = { version = "0.6.0", default-features = false, features = ["pypi"], optional = true }
+walkdir = { version = "2.3.2" }
+
+[dev-dependencies]
+assert_cmd = { version = "2.0.4" }
+strum = { version = "0.24.1" }
+ureq = { version = "2.5.0", features = [] }
+
+[features]
+default = ["update-informer"]
+update-informer = ["dep:update-informer"]
+
+[package.metadata.maturin]
+name = "ruff"
+# Setting the name here is necessary for maturin to include the package in its builds.

ruff_cli/src/cache.rs

@@ -0,0 +1,124 @@
+use std::collections::hash_map::DefaultHasher;
+use std::fs;
+use std::hash::{Hash, Hasher};
+use std::io::Write;
+use std::path::Path;
+
+use anyhow::Result;
+use filetime::FileTime;
+use log::error;
+use path_absolutize::Absolutize;
+use ruff::message::Message;
+use ruff::settings::{flags, Settings};
+use serde::{Deserialize, Serialize};
+
+const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+#[derive(Serialize, Deserialize)]
+struct CacheMetadata {
+    mtime: i64,
+}
+
+#[derive(Serialize)]
+struct CheckResultRef<'a> {
+    metadata: &'a CacheMetadata,
+    messages: &'a [Message],
+}
+
+#[derive(Deserialize)]
+struct CheckResult {
+    metadata: CacheMetadata,
+    messages: Vec<Message>,
+}
+
+fn content_dir() -> &'static Path {
+    Path::new("content")
+}
+
+fn cache_key<P: AsRef<Path>>(path: P, settings: &Settings, autofix: flags::Autofix) -> u64 {
+    let mut hasher = DefaultHasher::new();
+    CARGO_PKG_VERSION.hash(&mut hasher);
+    path.as_ref().absolutize().unwrap().hash(&mut hasher);
+    settings.hash(&mut hasher);
+    autofix.hash(&mut hasher);
+    hasher.finish()
+}
+
+#[allow(dead_code)]
+/// Initialize the cache at the specified `Path`.
+pub fn init(path: &Path) -> Result<()> {
+    // Create the cache directories.
+    fs::create_dir_all(path.join(content_dir()))?;
+
+    // Add the CACHEDIR.TAG.
+    if !cachedir::is_tagged(path)? {
+        cachedir::add_tag(path)?;
+    }
+
+    // Add the .gitignore.
+    let gitignore_path = path.join(".gitignore");
+    if !gitignore_path.exists() {
+        let mut file = fs::File::create(gitignore_path)?;
+        file.write_all(b"*")?;
+    }
+
+    Ok(())
+}
+
+fn write_sync(cache_dir: &Path, key: u64, value: &[u8]) -> Result<(), std::io::Error> {
+    fs::write(
+        cache_dir.join(content_dir()).join(format!("{key:x}")),
+        value,
+    )
+}
+
+fn read_sync(cache_dir: &Path, key: u64) -> Result<Vec<u8>, std::io::Error> {
+    fs::read(cache_dir.join(content_dir()).join(format!("{key:x}")))
+}
+
+/// Get a value from the cache.
+pub fn get<P: AsRef<Path>>(
+    path: P,
+    metadata: &fs::Metadata,
+    settings: &Settings,
+    autofix: flags::Autofix,
+) -> Option<Vec<Message>> {
+    let encoded = read_sync(&settings.cache_dir, cache_key(path, settings, autofix)).ok()?;
+    let (mtime, messages) = match bincode::deserialize::<CheckResult>(&encoded[..]) {
+        Ok(CheckResult {
+            metadata: CacheMetadata { mtime },
+            messages,
+        }) => (mtime, messages),
+        Err(e) => {
+            error!("Failed to deserialize encoded cache entry: {e:?}");
+            return None;
+        }
+    };
+    if FileTime::from_last_modification_time(metadata).unix_seconds() != mtime {
+        return None;
+    }
+    Some(messages)
+}
+
+/// Set a value in the cache.
+pub fn set<P: AsRef<Path>>(
+    path: P,
+    metadata: &fs::Metadata,
+    settings: &Settings,
+    autofix: flags::Autofix,
+    messages: &[Message],
+) {
+    let check_result = CheckResultRef {
+        metadata: &CacheMetadata {
+            mtime: FileTime::from_last_modification_time(metadata).unix_seconds(),
+        },
+        messages,
+    };
+    if let Err(e) = write_sync(
+        &settings.cache_dir,
+        cache_key(path, settings, autofix),
+        &bincode::serialize(&check_result).unwrap(),
+    ) {
+        error!("Failed to write to cache: {e:?}");
+    }
+}

ruff_cli/src/cli.rs

@@ -2,18 +2,21 @@ use std::path::{Path, PathBuf};
 
 use clap::{command, Parser};
 use regex::Regex;
-use rustc_hash::FxHashMap;
-
-use crate::fs;
-use crate::logging::LogLevel;
-use crate::registry::CheckCode;
-use crate::registry_gen::CheckCodePrefix;
-use crate::settings::types::{
+use ruff::fs;
+use ruff::logging::LogLevel;
+use ruff::registry::{RuleCode, RuleCodePrefix};
+use ruff::resolver::ConfigProcessor;
+use ruff::settings::types::{
     FilePattern, PatternPrefixPair, PerFileIgnore, PythonVersion, SerializationFormat,
 };
+use rustc_hash::FxHashMap;
 
 #[derive(Debug, Parser)]
-#[command(author, about = "Ruff: An extremely fast Python linter.")]
+#[command(
+    author,
+    name = "ruff",
+    about = "Ruff: An extremely fast Python linter."
+)]
 #[command(version)]
 #[allow(clippy::struct_excessive_bools)]
 pub struct Cli {
@@ -21,31 +24,31 @@ 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")]
     pub verbose: bool,
-    /// Only log errors.
+    /// Print lint violations, but nothing else.
     #[arg(short, long, group = "verbosity")]
     pub quiet: bool,
     /// Disable all logging (but still exit with status code "1" upon detecting
-    /// errors).
+    /// lint violations).
     #[arg(short, long, group = "verbosity")]
     pub silent: bool,
-    /// Exit with status code "0", even upon detecting errors.
+    /// Exit with status code "0", even upon detecting lint violations.
     #[arg(short, long)]
     pub exit_zero: bool,
     /// Run in watch mode by re-running whenever files change.
     #[arg(short, long)]
     pub watch: bool,
-    /// Attempt to automatically fix lint errors.
+    /// Attempt to automatically fix lint violations.
     #[arg(long, overrides_with("no_fix"))]
     fix: bool,
     #[clap(long, overrides_with("fix"), hide = true)]
     no_fix: bool,
-    /// Fix any fixable lint errors, but don't report on leftover violations.
-    /// Implies `--fix`.
+    /// Fix any fixable lint violations, but don't report on leftover
+    /// violations. Implies `--fix`.
     #[arg(long, overrides_with("no_fix_only"))]
     fix_only: bool,
     #[clap(long, overrides_with("fix_only"), hide = true)]
@@ -57,47 +60,50 @@ 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).
-    #[arg(long, value_delimiter = ',')]
-    pub select: Option<Vec<CheckCodePrefix>>,
-    /// Like --select, but adds additional error codes on top of the selected
+    /// 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 = ',', value_name = "RULE_CODE")]
+    pub select: Option<Vec<RuleCodePrefix>>,
+    /// Like --select, but adds additional rule codes on top of the selected
     /// ones.
-    #[arg(long, value_delimiter = ',')]
-    pub extend_select: Option<Vec<CheckCodePrefix>>,
-    /// Comma-separated list of error codes to disable.
-    #[arg(long, value_delimiter = ',')]
-    pub ignore: Option<Vec<CheckCodePrefix>>,
-    /// Like --ignore, but adds additional error codes on top of the ignored
+    #[arg(long, value_delimiter = ',', value_name = "RULE_CODE")]
+    pub extend_select: Option<Vec<RuleCodePrefix>>,
+    /// Comma-separated list of rule codes to disable.
+    #[arg(long, value_delimiter = ',', value_name = "RULE_CODE")]
+    pub ignore: Option<Vec<RuleCodePrefix>>,
+    /// Like --ignore, but adds additional rule codes on top of the ignored
     /// ones.
-    #[arg(long, value_delimiter = ',')]
-    pub extend_ignore: Option<Vec<CheckCodePrefix>>,
-    /// List of paths, used to exclude files and/or directories from checks.
-    #[arg(long, value_delimiter = ',')]
+    #[arg(long, value_delimiter = ',', value_name = "RULE_CODE")]
+    pub extend_ignore: Option<Vec<RuleCodePrefix>>,
+    /// List of paths, used to omit files and/or directories from analysis.
+    #[arg(long, value_delimiter = ',', value_name = "FILE_PATTERN")]
     pub exclude: Option<Vec<FilePattern>>,
-    /// Like --exclude, but adds additional files and directories on top of the
-    /// excluded ones.
-    #[arg(long, value_delimiter = ',')]
+    /// Like --exclude, but adds additional files and directories on top of
+    /// those already excluded.
+    #[arg(long, value_delimiter = ',', value_name = "FILE_PATTERN")]
     pub extend_exclude: Option<Vec<FilePattern>>,
-    /// List of error codes to treat as eligible for autofix. Only applicable
+    /// List of rule 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>>,
-    /// List of error codes to treat as ineligible for autofix. Only applicable
+    #[arg(long, value_delimiter = ',', value_name = "RULE_CODE")]
+    pub fixable: Option<Vec<RuleCodePrefix>>,
+    /// List of rule 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>>,
+    #[arg(long, value_delimiter = ',', value_name = "RULE_CODE")]
+    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)]
+    /// Output serialization format for violations.
+    #[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"))]
@@ -127,13 +133,10 @@ pub struct Cli {
     /// The minimum Python version that should be supported.
     #[arg(long)]
     pub target_version: Option<PythonVersion>,
-    /// Set the line-length for length-associated checks and automatic
+    /// Set the line-length for length-associated rules and automatic
     /// formatting.
     #[arg(long)]
     pub line_length: Option<usize>,
-    /// Maximum McCabe complexity allowed for a given function.
-    #[arg(long)]
-    pub max_complexity: Option<usize>,
     /// Enable automatic additions of `noqa` directives to failing lines.
     #[arg(
         long,
@@ -177,7 +180,7 @@ pub struct Cli {
         conflicts_with = "stdin_filename",
         conflicts_with = "watch",
     )]
-    pub explain: Option<CheckCode>,
+    pub explain: Option<RuleCode>,
     /// Generate shell completion
     #[arg(
         long,
@@ -210,7 +213,7 @@ pub struct Cli {
         conflicts_with = "watch",
     )]
     pub show_files: bool,
-    /// See the settings Ruff will use to check a given Python file.
+    /// See the settings Ruff will use to lint a given Python file.
     #[arg(
         long,
         // Fake subcommands.
@@ -241,6 +244,7 @@ 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,
@@ -259,7 +263,6 @@ impl Cli {
                 fixable: self.fixable,
                 ignore: self.ignore,
                 line_length: self.line_length,
-                max_complexity: self.max_complexity,
                 per_file_ignores: self.per_file_ignores,
                 respect_gitignore: resolve_bool_arg(
                     self.respect_gitignore,
@@ -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 +323,17 @@ 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>,
@@ -340,6 +343,82 @@ pub struct Overrides {
     pub update_check: Option<bool>,
 }
 
+impl ConfigProcessor for &Overrides {
+    fn process_config(&self, config: &mut ruff::settings::configuration::Configuration) {
+        if let Some(cache_dir) = &self.cache_dir {
+            config.cache_dir = Some(cache_dir.clone());
+        }
+        if let Some(dummy_variable_rgx) = &self.dummy_variable_rgx {
+            config.dummy_variable_rgx = Some(dummy_variable_rgx.clone());
+        }
+        if let Some(exclude) = &self.exclude {
+            config.exclude = Some(exclude.clone());
+        }
+        if let Some(extend_exclude) = &self.extend_exclude {
+            config.extend_exclude.extend(extend_exclude.clone());
+        }
+        if let Some(fix) = &self.fix {
+            config.fix = Some(*fix);
+        }
+        if let Some(fix_only) = &self.fix_only {
+            config.fix_only = Some(*fix_only);
+        }
+        if let Some(fixable) = &self.fixable {
+            config.fixable = Some(fixable.clone());
+        }
+        if let Some(format) = &self.format {
+            config.format = Some(*format);
+        }
+        if let Some(force_exclude) = &self.force_exclude {
+            config.force_exclude = Some(*force_exclude);
+        }
+        if let Some(ignore) = &self.ignore {
+            config.ignore = Some(ignore.clone());
+        }
+        if let Some(line_length) = &self.line_length {
+            config.line_length = Some(*line_length);
+        }
+        if let Some(per_file_ignores) = &self.per_file_ignores {
+            config.per_file_ignores = Some(collect_per_file_ignores(per_file_ignores.clone()));
+        }
+        if let Some(respect_gitignore) = &self.respect_gitignore {
+            config.respect_gitignore = Some(*respect_gitignore);
+        }
+        if let Some(select) = &self.select {
+            config.select = Some(select.clone());
+        }
+        if let Some(show_source) = &self.show_source {
+            config.show_source = Some(*show_source);
+        }
+        if let Some(target_version) = &self.target_version {
+            config.target_version = Some(*target_version);
+        }
+        if let Some(unfixable) = &self.unfixable {
+            config.unfixable = Some(unfixable.clone());
+        }
+        if let Some(update_check) = &self.update_check {
+            config.update_check = Some(*update_check);
+        }
+        // Special-case: `extend_ignore` and `extend_select` are parallel arrays, so
+        // push an empty array if only one of the two is provided.
+        match (&self.extend_ignore, &self.extend_select) {
+            (Some(extend_ignore), Some(extend_select)) => {
+                config.extend_ignore.push(extend_ignore.clone());
+                config.extend_select.push(extend_select.clone());
+            }
+            (Some(extend_ignore), None) => {
+                config.extend_ignore.push(extend_ignore.clone());
+                config.extend_select.push(Vec::new());
+            }
+            (None, Some(extend_select)) => {
+                config.extend_ignore.push(Vec::new());
+                config.extend_select.push(extend_select.clone());
+            }
+            (None, None) => {}
+        }
+    }
+}
+
 /// Map the CLI settings to a `LogLevel`.
 pub fn extract_log_level(cli: &Arguments) -> LogLevel {
     if cli.silent {
@@ -355,7 +434,7 @@ 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)

ruff_cli/src/commands.rs

@@ -11,22 +11,22 @@ use log::{debug, error};
 use path_absolutize::path_dedot;
 #[cfg(not(target_family = "wasm"))]
 use rayon::prelude::*;
-use rustpython_ast::Location;
+use ruff::cache::CACHE_DIR_NAME;
+use ruff::linter::add_noqa_to_path;
+use ruff::logging::LogLevel;
+use ruff::message::{Location, Message};
+use ruff::registry::RuleCode;
+use ruff::resolver::{FileDiscovery, PyprojectDiscovery};
+use ruff::settings::flags;
+use ruff::settings::types::SerializationFormat;
+use ruff::{fix, fs, packaging, resolver, warn_user_once, IOError};
 use serde::Serialize;
 use walkdir::WalkDir;
 
-use crate::autofix::fixer;
-use crate::cache::DEFAULT_CACHE_DIR_NAME;
+use crate::cache;
 use crate::cli::Overrides;
+use crate::diagnostics::{lint_path, lint_stdin, Diagnostics};
 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::resolver::{FileDiscovery, PyprojectDiscovery};
-use crate::settings::flags;
-use crate::settings::types::SerializationFormat;
-use crate::{cache, fs, one_time_warning, packages, resolver};
 
 /// Run the linter over a collection of files.
 pub fn run(
@@ -35,7 +35,7 @@ pub fn run(
     file_strategy: &FileDiscovery,
     overrides: &Overrides,
     cache: flags::Cache,
-    autofix: fixer::Mode,
+    autofix: fix::FixMode,
 ) -> Result<Diagnostics> {
     // Collect all the Python files to check.
     let start = Instant::now();
@@ -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());
     }
 
@@ -82,12 +77,14 @@ pub fn run(
     };
 
     // Discover the package root for each Python file.
-    let package_roots = packages::detect_package_roots(
+    let package_roots = packaging::detect_package_roots(
         &paths
             .iter()
             .flatten()
             .map(ignore::DirEntry::path)
             .collect::<Vec<_>>(),
+        &resolver,
+        pyproject_strategy,
     );
 
     let start = Instant::now();
@@ -117,9 +114,9 @@ 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: IOError(message).into(),
                             location: Location::default(),
                             end_location: Location::default(),
                             fix: None,
@@ -161,7 +158,7 @@ pub fn run_stdin(
     pyproject_strategy: &PyprojectDiscovery,
     file_strategy: &FileDiscovery,
     overrides: &Overrides,
-    autofix: fixer::Mode,
+    autofix: fix::FixMode,
 ) -> Result<Diagnostics> {
     if let Some(filename) = filename {
         if !resolver::python_file_at_path(filename, pyproject_strategy, file_strategy, overrides)? {
@@ -174,7 +171,7 @@ pub fn run_stdin(
     };
     let package_root = filename
         .and_then(Path::parent)
-        .and_then(packages::detect_package_root);
+        .and_then(|path| packaging::detect_package_root(path, &settings.namespace_packages));
     let stdin = read_from_stdin()?;
     let mut diagnostics = lint_stdin(filename, package_root, &stdin, settings, autofix)?;
     diagnostics.messages.sort_unstable();
@@ -196,12 +193,7 @@ 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 +263,7 @@ 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 +285,18 @@ 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 +305,7 @@ 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 +327,10 @@ 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());

ruff_cli/src/diagnostics.rs

@@ -0,0 +1,155 @@
+#![cfg_attr(target_family = "wasm", allow(dead_code))]
+use std::fs::write;
+use std::io;
+use std::io::Write;
+use std::ops::AddAssign;
+use std::path::Path;
+
+use anyhow::Result;
+use log::debug;
+use ruff::linter::{lint_fix, lint_only};
+use ruff::message::Message;
+use ruff::settings::{flags, Settings};
+use ruff::{fix, fs};
+use similar::TextDiff;
+
+use crate::cache;
+
+#[derive(Debug, Default)]
+pub struct Diagnostics {
+    pub messages: Vec<Message>,
+    pub fixed: usize,
+}
+
+impl Diagnostics {
+    pub fn new(messages: Vec<Message>) -> Self {
+        Self { messages, fixed: 0 }
+    }
+}
+
+impl AddAssign for Diagnostics {
+    fn add_assign(&mut self, other: Self) {
+        self.messages.extend(other.messages);
+        self.fixed += other.fixed;
+    }
+}
+
+/// Lint the source code at the given `Path`.
+pub fn lint_path(
+    path: &Path,
+    package: Option<&Path>,
+    settings: &Settings,
+    cache: flags::Cache,
+    autofix: fix::FixMode,
+) -> Result<Diagnostics> {
+    // Validate the `Settings` and return any errors.
+    settings.validate()?;
+
+    // Check the cache.
+    // TODO(charlie): `fixer::Mode::Apply` and `fixer::Mode::Diff` both have
+    // side-effects that aren't captured in the cache. (In practice, it's fine
+    // to cache `fixer::Mode::Apply`, since a file either has no fixes, or we'll
+    // write the fixes to disk, thus invalidating the cache. But it's a bit hard
+    // to reason about. We need to come up with a better solution here.)
+    let metadata = if matches!(cache, flags::Cache::Enabled)
+        && matches!(autofix, fix::FixMode::None | fix::FixMode::Generate)
+    {
+        let metadata = path.metadata()?;
+        if let Some(messages) = cache::get(path, &metadata, settings, autofix.into()) {
+            debug!("Cache hit for: {}", path.to_string_lossy());
+            return Ok(Diagnostics::new(messages));
+        }
+        Some(metadata)
+    } else {
+        None
+    };
+
+    // Read the file from disk.
+    let contents = fs::read_file(path)?;
+
+    // Lint the file.
+    let (messages, fixed) = if matches!(autofix, fix::FixMode::Apply | fix::FixMode::Diff) {
+        let (transformed, fixed, messages) = lint_fix(&contents, path, package, settings)?;
+        if fixed > 0 {
+            if matches!(autofix, fix::FixMode::Apply) {
+                write(path, transformed)?;
+            } else if matches!(autofix, fix::FixMode::Diff) {
+                let mut stdout = io::stdout().lock();
+                TextDiff::from_lines(&contents, &transformed)
+                    .unified_diff()
+                    .header(&fs::relativize_path(path), &fs::relativize_path(path))
+                    .to_writer(&mut stdout)?;
+                stdout.write_all(b"\n")?;
+                stdout.flush()?;
+            }
+        }
+        (messages, fixed)
+    } else {
+        let messages = lint_only(&contents, path, package, settings, autofix.into())?;
+        let fixed = 0;
+        (messages, fixed)
+    };
+
+    // Re-populate the cache.
+    if let Some(metadata) = metadata {
+        cache::set(path, &metadata, settings, autofix.into(), &messages);
+    }
+
+    Ok(Diagnostics { messages, fixed })
+}
+
+/// Generate `Diagnostic`s from source code content derived from
+/// stdin.
+pub fn lint_stdin(
+    path: Option<&Path>,
+    package: Option<&Path>,
+    contents: &str,
+    settings: &Settings,
+    autofix: fix::FixMode,
+) -> Result<Diagnostics> {
+    // Validate the `Settings` and return any errors.
+    settings.validate()?;
+
+    // Lint the inputs.
+    let (messages, fixed) = if matches!(autofix, fix::FixMode::Apply | fix::FixMode::Diff) {
+        let (transformed, fixed, messages) = lint_fix(
+            contents,
+            path.unwrap_or_else(|| Path::new("-")),
+            package,
+            settings,
+        )?;
+
+        if matches!(autofix, fix::FixMode::Apply) {
+            // Write the contents to stdout, regardless of whether any errors were fixed.
+            io::stdout().write_all(transformed.as_bytes())?;
+        } else if matches!(autofix, fix::FixMode::Diff) {
+            // But only write a diff if it's non-empty.
+            if fixed > 0 {
+                let text_diff = TextDiff::from_lines(contents, &transformed);
+                let mut unified_diff = text_diff.unified_diff();
+                if let Some(path) = path {
+                    unified_diff.header(&fs::relativize_path(path), &fs::relativize_path(path));
+                }
+
+                let mut stdout = io::stdout().lock();
+                unified_diff.to_writer(&mut stdout)?;
+                stdout.write_all(b"\n")?;
+                stdout.flush()?;
+            }
+        }
+
+        (messages, fixed)
+    } else {
+        let messages = lint_only(
+            contents,
+            path.unwrap_or_else(|| Path::new("-")),
+            package,
+            settings,
+            autofix.into(),
+        )?;
+        let fixed = 0;
+        (messages, fixed)
+    };
+
+    Ok(Diagnostics { messages, fixed })
+}

ruff_cli/src/lib.rs

@@ -0,0 +1,14 @@
+//! This library only exists to enable the Ruff internal tooling (`ruff_dev`)
+//! to automatically update the `ruff --help` output in the `README.md`.
+//!
+//! For the actual Ruff library, see [`ruff`].
+#![allow(clippy::must_use_candidate, dead_code)]
+
+mod cli;
+
+use clap::CommandFactory;
+
+/// Returns the output of `ruff --help`.
+pub fn help() -> String {
+    cli::Cli::command().render_help().to_string()
+}

ruff_cli/src/main.rs

@@ -1,70 +1,79 @@
 #![allow(
-    clippy::collapsible_else_if,
-    clippy::collapsible_if,
-    clippy::implicit_hasher,
     clippy::match_same_arms,
     clippy::missing_errors_doc,
-    clippy::missing_panics_doc,
     clippy::module_name_repetitions,
-    clippy::must_use_candidate,
-    clippy::similar_names,
     clippy::too_many_lines
 )]
+#![forbid(unsafe_code)]
 
 use std::io::{self};
 use std::path::{Path, PathBuf};
 use std::process::ExitCode;
 use std::sync::mpsc::channel;
 
-use ::ruff::autofix::fixer;
-use ::ruff::cli::{extract_log_level, Cli, Overrides};
-use ::ruff::commands;
 use ::ruff::logging::{set_up_logging, LogLevel};
-use ::ruff::printer::{Printer, Violations};
-use ::ruff::resolver::{resolve_settings, FileDiscovery, PyprojectDiscovery, Relativity};
+use ::ruff::resolver::{
+    resolve_settings_with_processor, ConfigProcessor, FileDiscovery, PyprojectDiscovery, Relativity,
+};
 use ::ruff::settings::configuration::Configuration;
 use ::ruff::settings::types::SerializationFormat;
 use ::ruff::settings::{pyproject, Settings};
-#[cfg(feature = "update-informer")]
-use ::ruff::updates;
+use ::ruff::{fix, fs, warn_user_once};
 use anyhow::Result;
 use clap::{CommandFactory, Parser};
+use cli::{extract_log_level, Cli, Overrides};
 use colored::Colorize;
 use notify::{recommended_watcher, RecursiveMode, Watcher};
 use path_absolutize::path_dedot;
-use ruff::one_time_warning;
+use printer::{Printer, Violations};
+
+mod cache;
+mod cli;
+mod commands;
+mod diagnostics;
+mod iterators;
+mod printer;
+#[cfg(all(feature = "update-informer"))]
+pub mod updates;
 
 /// Resolve the relevant settings strategy and defaults for the current
 /// invocation.
 fn resolve(
+    isolated: bool,
     config: Option<&Path>,
     overrides: &Overrides,
     stdin_filename: Option<&Path>,
 ) -> Result<PyprojectDiscovery> {
-    if let Some(pyproject) = config {
-        // First priority: the user specified a `pyproject.toml` file. Use that
+    if isolated {
+        // First priority: if we're running in isolated mode, use the default settings.
+        let mut config = Configuration::default();
+        overrides.process_config(&mut config);
+        let settings = Settings::from_configuration(config, &path_dedot::CWD)?;
+        Ok(PyprojectDiscovery::Fixed(settings))
+    } else if let Some(pyproject) = config {
+        // Second priority: the user specified a `pyproject.toml` file. Use that
         // `pyproject.toml` for _all_ configuration, and resolve paths relative to the
         // current working directory. (This matches ESLint's behavior.)
-        let settings = resolve_settings(pyproject, &Relativity::Cwd, Some(overrides))?;
+        let settings = resolve_settings_with_processor(pyproject, &Relativity::Cwd, overrides)?;
         Ok(PyprojectDiscovery::Fixed(settings))
     } else if let Some(pyproject) = pyproject::find_settings_toml(
         stdin_filename
             .as_ref()
             .unwrap_or(&path_dedot::CWD.as_path()),
     )? {
-        // Second priority: find a `pyproject.toml` file in either an ancestor of
+        // Third priority: find a `pyproject.toml` file in either an ancestor of
         // `stdin_filename` (if set) or the current working path all paths relative to
         // that directory. (With `Strategy::Hierarchical`, we'll end up finding
         // the "closest" `pyproject.toml` file for every Python file later on,
         // so these act as the "default" settings.)
-        let settings = resolve_settings(&pyproject, &Relativity::Parent, Some(overrides))?;
+        let settings = resolve_settings_with_processor(&pyproject, &Relativity::Parent, overrides)?;
         Ok(PyprojectDiscovery::Hierarchical(settings))
     } else if let Some(pyproject) = pyproject::find_user_settings_toml() {
-        // Third priority: find a user-specific `pyproject.toml`, but resolve all paths
+        // Fourth priority: find a user-specific `pyproject.toml`, but resolve all paths
         // relative the current working directory. (With `Strategy::Hierarchical`, we'll
         // end up the "closest" `pyproject.toml` file for every Python file later on, so
         // these act as the "default" settings.)
-        let settings = resolve_settings(&pyproject, &Relativity::Cwd, Some(overrides))?;
+        let settings = resolve_settings_with_processor(&pyproject, &Relativity::Cwd, overrides)?;
         Ok(PyprojectDiscovery::Hierarchical(settings))
     } else {
         // Fallback: load Ruff's default settings, and resolve all paths relative to the
@@ -72,14 +81,13 @@ fn resolve(
         // "closest" `pyproject.toml` file for every Python file later on, so these act
         // as the "default" settings.)
         let mut config = Configuration::default();
-        // Apply command-line options that override defaults.
-        config.apply(overrides.clone());
+        overrides.process_config(&mut config);
         let settings = Settings::from_configuration(config, &path_dedot::CWD)?;
         Ok(PyprojectDiscovery::Hierarchical(settings))
     }
 }
 
-pub(crate) fn inner_main() -> Result<ExitCode> {
+pub fn main() -> Result<ExitCode> {
     // Extract command-line arguments.
     let (cli, overrides) = Cli::parse().partition();
     let log_level = extract_log_level(&cli);
@@ -97,6 +105,7 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
     // Construct the "default" settings. These are used when no `pyproject.toml`
     // files are present, or files are injected from outside of the hierarchy.
     let pyproject_strategy = resolve(
+        cli.isolated,
         cli.config.as_deref(),
         &overrides,
         cli.stdin_filename.as_deref(),
@@ -136,7 +145,7 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
     };
 
     if let Some(code) = cli.explain {
-        commands::explain(&code, &format)?;
+        commands::explain(&code, format)?;
         return Ok(ExitCode::SUCCESS);
     }
     if cli.show_settings {
@@ -159,13 +168,13 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
     // but not apply fixes. That would allow us to avoid special-casing JSON
     // here.
     let autofix = if cli.diff {
-        fixer::Mode::Diff
+        fix::FixMode::Diff
     } else if fix || fix_only {
-        fixer::Mode::Apply
+        fix::FixMode::Apply
     } else if matches!(format, SerializationFormat::Json) {
-        fixer::Mode::Generate
+        fix::FixMode::Generate
     } else {
-        fixer::Mode::None
+        fix::FixMode::None
     };
     let violations = if cli.diff || fix_only {
         Violations::Hide
@@ -178,31 +187,16 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
     if cache {
         // `--no-cache` doesn't respect code changes, and so is often confusing during
         // development.
-        one_time_warning!(
-            "{}{} {}",
-            "warning".yellow().bold(),
-            ":".bold(),
-            "debug build without --no-cache.".bold()
-        );
+        warn_user_once!("debug build without --no-cache.");
     }
 
     let printer = Printer::new(&format, &log_level, &autofix, &violations);
     if cli.watch {
-        if !matches!(autofix, fixer::Mode::None) {
-            one_time_warning!(
-                "{}{} {}",
-                "warning".yellow().bold(),
-                ":".bold(),
-                "--fix is not enabled in watch mode.".bold()
-            );
+        if !matches!(autofix, fix::FixMode::None) {
+            warn_user_once!("--fix is not enabled in watch mode.");
         }
         if format != SerializationFormat::Text {
-            one_time_warning!(
-                "{}{} {}",
-                "warning".yellow().bold(),
-                ":".bold(),
-                "--format 'text' is used in watch mode.".bold()
-            );
+            warn_user_once!("--format 'text' is used in watch mode.");
         }
 
         // Perform an initial run instantly.
@@ -215,9 +209,9 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
             &file_strategy,
             &overrides,
             cache.into(),
-            fixer::Mode::None,
+            fix::FixMode::None,
         )?;
-        printer.write_continuously(&messages)?;
+        printer.write_continuously(&messages);
 
         // Configure the file watcher.
         let (tx, rx) = channel();
@@ -245,9 +239,9 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
                             &file_strategy,
                             &overrides,
                             cache.into(),
-                            fixer::Mode::None,
+                            fix::FixMode::None,
                         )?;
-                        printer.write_continuously(&messages)?;
+                        printer.write_continuously(&messages);
                     }
                 }
                 Err(err) => return Err(err.into()),
@@ -265,7 +259,7 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
         // Generate lint violations.
         let diagnostics = if is_stdin {
             commands::run_stdin(
-                cli.stdin_filename.as_deref(),
+                cli.stdin_filename.map(fs::normalize_path).as_deref(),
                 &pyproject_strategy,
                 &file_strategy,
                 &overrides,
@@ -285,7 +279,7 @@ pub(crate) fn inner_main() -> Result<ExitCode> {
         // Always try to print violations (the printer itself may suppress output),
         // unless we're writing fixes via stdin (in which case, the transformed
         // source code goes to stdout).
-        if !(is_stdin && matches!(autofix, fixer::Mode::Apply | fixer::Mode::Diff)) {
+        if !(is_stdin && matches!(autofix, fix::FixMode::Apply | fix::FixMode::Diff)) {
             printer.write_once(&diagnostics)?;
         }
 

ruff_cli/src/printer.rs

@@ -6,18 +6,16 @@ use annotate_snippets::snippet::{Annotation, AnnotationType, Slice, Snippet, Sou
 use anyhow::Result;
 use colored::Colorize;
 use itertools::iterate;
-use rustpython_parser::ast::Location;
+use ruff::fs::relativize_path;
+use ruff::logging::LogLevel;
+use ruff::message::{Location, Message};
+use ruff::registry::RuleCode;
+use ruff::settings::types::SerializationFormat;
+use ruff::{fix, notify_user};
 use serde::Serialize;
 use serde_json::json;
 
-use crate::autofix::fixer;
-use crate::fs::relativize_path;
-use crate::linter::Diagnostics;
-use crate::logging::LogLevel;
-use crate::message::Message;
-use crate::registry::CheckCode;
-use crate::settings::types::SerializationFormat;
-use crate::tell_user;
+use crate::diagnostics::Diagnostics;
 
 /// Enum to control whether lint violations are shown to the user.
 pub enum Violations {
@@ -35,7 +33,7 @@ struct ExpandedFix<'a> {
 
 #[derive(Serialize)]
 struct ExpandedMessage<'a> {
-    code: &'a CheckCode,
+    code: &'a RuleCode,
     message: String,
     fix: Option<ExpandedFix<'a>>,
     location: Location,
@@ -46,7 +44,7 @@ struct ExpandedMessage<'a> {
 pub struct Printer<'a> {
     format: &'a SerializationFormat,
     log_level: &'a LogLevel,
-    autofix: &'a fixer::Mode,
+    autofix: &'a fix::FixMode,
     violations: &'a Violations,
 }
 
@@ -54,7 +52,7 @@ impl<'a> Printer<'a> {
     pub fn new(
         format: &'a SerializationFormat,
         log_level: &'a LogLevel,
-        autofix: &'a fixer::Mode,
+        autofix: &'a fix::FixMode,
         violations: &'a Violations,
     ) -> Self {
         Self {
@@ -67,7 +65,7 @@ impl<'a> Printer<'a> {
 
     pub fn write_to_user(&self, message: &str) {
         if self.log_level >= &LogLevel::Default {
-            tell_user!("{}", message);
+            notify_user!("{}", message);
         }
     }
 
@@ -84,7 +82,7 @@ impl<'a> Printer<'a> {
                         println!("Found {remaining} error(s).");
                     }
 
-                    if !matches!(self.autofix, fixer::Mode::Apply) {
+                    if !matches!(self.autofix, fix::FixMode::Apply) {
                         let num_fixable = diagnostics
                             .messages
                             .iter()
@@ -98,9 +96,9 @@ impl<'a> Printer<'a> {
                 Violations::Hide => {
                     let fixed = diagnostics.fixed;
                     if fixed > 0 {
-                        if matches!(self.autofix, fixer::Mode::Apply) {
+                        if matches!(self.autofix, fix::FixMode::Apply) {
                             println!("Fixed {fixed} error(s).");
-                        } else if matches!(self.autofix, fixer::Mode::Diff) {
+                        } else if matches!(self.autofix, fix::FixMode::Diff) {
                             println!("Would fix {fixed} error(s).");
                         }
                     }
@@ -223,19 +221,30 @@ impl<'a> Printer<'a> {
                 self.post_text(diagnostics);
             }
             SerializationFormat::Github => {
-                // Generate error workflow command in GitHub Actions format
-                // https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message
+                // Generate error workflow command in GitHub Actions format.
+                // See: https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message
                 diagnostics.messages.iter().for_each(|message| {
-                    println!(
-                        "::notice title=Ruff,file={},line={},col={},endLine={},endColumn={}::({}) \
-                         {}",
+                    let label = format!(
+                        "{}{}{}{}{}{} {} {}",
                         relativize_path(Path::new(&message.filename)),
+                        ":",
+                        message.location.row(),
+                        ":",
+                        message.location.column(),
+                        ":",
+                        message.kind.code().as_ref(),
+                        message.kind.body(),
+                    );
+                    println!(
+                        "::error title=Ruff \
+                         ({}),file={},line={},col={},endLine={},endColumn={}::{}",
+                        message.kind.code(),
+                        message.filename,
                         message.location.row(),
                         message.location.column(),
                         message.end_location.row(),
                         message.end_location.column(),
-                        message.kind.code(),
-                        message.kind.body(),
+                        label,
                     );
                 });
             }
@@ -254,7 +263,7 @@ impl<'a> Printer<'a> {
                                     "severity": "major",
                                     "fingerprint": message.kind.code(),
                                     "location": {
-                                        "path": relativize_path(Path::new(&message.filename)),
+                                        "path": message.filename,
                                         "lines": {
                                             "begin": message.location.row(),
                                             "end": message.end_location.row()
@@ -272,13 +281,13 @@ impl<'a> Printer<'a> {
         Ok(())
     }
 
-    pub fn write_continuously(&self, diagnostics: &Diagnostics) -> Result<()> {
+    pub fn write_continuously(&self, diagnostics: &Diagnostics) {
         if matches!(self.log_level, LogLevel::Silent) {
-            return Ok(());
+            return;
         }
 
         if self.log_level >= &LogLevel::Default {
-            tell_user!(
+            notify_user!(
                 "Found {} error(s). Watching for file changes.",
                 diagnostics.messages.len()
             );
@@ -292,10 +301,9 @@ impl<'a> Printer<'a> {
                 print_message(message);
             }
         }
-
-        Ok(())
     }
 
+    #[allow(clippy::unused_self)]
     pub fn clear_screen(&self) -> Result<()> {
         #[cfg(not(target_family = "wasm"))]
         clearscreen::clear()?;
@@ -303,7 +311,7 @@ impl<'a> Printer<'a> {
     }
 }
 
-fn group_messages_by_filename(messages: &Vec<Message>) -> BTreeMap<&String, Vec<&Message>> {
+fn group_messages_by_filename(messages: &[Message]) -> BTreeMap<&String, Vec<&Message>> {
     let mut grouped_messages = BTreeMap::default();
     for message in messages {
         grouped_messages