Bump version to 0.0.181

Detect unused arguments

.github/workflows/ci.yaml

@@ -20,6 +20,9 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
+          toolchain: nightly-2022-11-01
+          override: true
+          components: rustfmt
       - uses: actions/cache@v3
         env:
           cache-name: cache-cargo
@@ -33,6 +36,12 @@ jobs:
             ${{ runner.os }}-build-
             ${{ runner.os }}-
       - run: cargo build --all --release
+      - run: ./target/release/ruff_dev generate-rules-table
+      - run: ./target/release/ruff_dev generate-options
+      - run: git diff --quiet README.md || echo "::error file=README.md::This file is outdated. You may have to rerun 'cargo dev generate-options' and/or 'cargo dev generate-rules-table'."
+      - run: ./target/release/ruff_dev generate-check-code-prefix && cargo fmt -- src/checks_gen.rs
+      - run: git diff --quiet src/checks_gen.rs || echo "::error file=src/checks_gen.rs::This file is outdated. You may have to rerun 'cargo dev generate-check-code-prefix'."
+      - run: git diff --exit-code -- README.md src/checks_gen.rs
 
   cargo_fmt:
     name: "cargo fmt"

.github/workflows/ruff.yaml

@@ -1,9 +1,8 @@
 name: "[ruff] Release"
 
 on:
-  create:
-    tags:
-      - v*
+  release:
+    types: [published]
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.161
+    rev: v0.0.181
     hooks:
       - id: ruff
 

BREAKING_CHANGES.md

@@ -0,0 +1,23 @@
+# Breaking Changes
+
+## 0.0.181
+
+### Files excluded by `.gitignore` are now ignored ([#1234](https://github.com/charliermarsh/ruff/pull/1234))
+
+Ruff will now avoid checking files that are excluded by `.ignore`, `.gitignore`,
+`.git/info/exclude`, and global `gitignore` files. This behavior is powered by the [`ignore`](https://docs.rs/ignore/latest/ignore/struct.WalkBuilder.html#ignore-rules)
+crate, and is applied in addition to Ruff's built-in `exclude` system.
+
+To disable this behavior, set `respect-gitignore = false` in your `pyproject.toml` file.
+
+Note that hidden files (i.e., files and directories prefixed with a `.`) are _not_ ignored by
+default.
+
+## 0.0.178
+
+### Configuration files are now resolved hierarchically ([#1190](https://github.com/charliermarsh/ruff/pull/1190))
+
+`pyproject.toml` files are now resolved hierarchically, such that for each Python file, we find
+the first `pyproject.toml` file in its path, and use that to determine its lint settings.
+
+See the [README](https://github.com/charliermarsh/ruff#pyprojecttoml-discovery) for more.

CONTRIBUTING.md

@@ -105,6 +105,8 @@ You may also want to add the new configuration option to the `flake8-to-ruff` to
 responsible for converting `flake8` configuration files to Ruff's TOML format. This logic
 lives in `flake8_to_ruff/src/converter.rs`.
 
+To update the documentation for supported configuration options, run `cargo dev generate-options`.
+
 ## Release process
 
 As of now, Ruff has an ad hoc release process: releases are cut with high frequency via GitHub

Cargo.lock

@@ -724,7 +724,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8-to-ruff"
-version = "0.0.161-dev.0"
+version = "0.0.181-dev.0"
 dependencies = [
  "anyhow",
  "clap 4.0.29",
@@ -796,6 +796,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "glob"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+
 [[package]]
 name = "globset"
 version = "0.4.9"
@@ -888,6 +894,24 @@ dependencies = [
  "unicode-normalization",
 ]
 
+[[package]]
+name = "ignore"
+version = "0.4.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "713f1b139373f96a2e0ce3ac931cd01ee973c3c5dd7c40c0c2efe96ad2b6751d"
+dependencies = [
+ "crossbeam-utils",
+ "globset",
+ "lazy_static",
+ "log",
+ "memchr",
+ "regex",
+ "same-file",
+ "thread_local",
+ "walkdir",
+ "winapi-util",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.9.2"
@@ -1821,7 +1845,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.161"
+version = "0.0.181"
 dependencies = [
  "annotate-snippets 0.9.1",
  "anyhow",
@@ -1841,7 +1865,9 @@ dependencies = [
  "fern",
  "filetime",
  "getrandom 0.2.8",
+ "glob",
  "globset",
+ "ignore",
  "insta",
  "itertools",
  "libcst",
@@ -1855,6 +1881,7 @@ dependencies = [
  "rayon",
  "regex",
  "ropey",
+ "ruff_macros",
  "rustc-hash",
  "rustpython-ast",
  "rustpython-common",
@@ -1873,7 +1900,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_dev"
-version = "0.0.161"
+version = "0.0.181"
 dependencies = [
  "anyhow",
  "clap 4.0.29",
@@ -1889,6 +1916,16 @@ dependencies = [
  "strum_macros",
 ]
 
+[[package]]
+name = "ruff_macros"
+version = "0.0.181"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "textwrap",
+]
+
 [[package]]
 name = "rustc-hash"
 version = "1.1.0"
@@ -1924,7 +1961,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -1934,7 +1971,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -1957,7 +1994,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "bincode",
  "bitflags",
@@ -1974,7 +2011,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ahash",
  "anyhow",
@@ -2286,6 +2323,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "thread_local"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5516c27b78311c50bf42c071425c560ac799b11c30b31f87e3081965fe5e0180"
+dependencies = [
+ "once_cell",
+]
+
 [[package]]
 name = "time"
 version = "0.1.45"

Cargo.toml

@@ -6,7 +6,7 @@ members = [
 
 [package]
 name = "ruff"
-version = "0.0.161"
+version = "0.0.181"
 edition = "2021"
 rust-version = "1.65.0"
 
@@ -28,7 +28,9 @@ common-path = { version = "1.0.0" }
 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" }
 itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
 log = { version = "0.4.17" }
@@ -41,10 +43,11 @@ quick-junit = { version = "0.3.2" }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
 ropey = { version = "1.5.0", features = ["cr_lines", "simd"], default-features = false }
+ruff_macros = { version = "0.0.181", path = "ruff_macros" }
 rustc-hash = { version = "1.1.0" }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
 serde = { version = "1.0.147", features = ["derive"] }
 serde_json = { version = "1.0.87" }
 strum = { version = "0.24.1", features = ["strum_macros"] }

LICENSE

@@ -388,6 +388,81 @@ are:
     SOFTWARE.
   """
 
+- flake8-import-conventions, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2021 João Palmeiro
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
+
+- flake8-unused-arguments, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2019 Nathan Hoad
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
+
+- flake8-simplify, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2020 Martin Thoma
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
+
 - isort, licensed as follows:
   """
     The MIT License (MIT)

create_plugin.sh

@@ -1,11 +0,0 @@
-set -euxo pipefail
-
-NAME=$1
-
-mkdir -p src/$1
-mkdir -p resources/test/fixtures/$1
-touch src/$1/mod.rs
-
-sed -i "" "s/mod flake8_print;/mod flake8_print; mod flake8_return;/g" src/lib.rs
-sed -i "" "s|// flake8-print|// flake8-return\n// flake8-print|g" src/checks.rs
-

flake8_to_ruff/Cargo.lock

@@ -771,7 +771,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8_to_ruff"
-version = "0.0.161"
+version = "0.0.181"
 dependencies = [
  "anyhow",
  "clap",
@@ -1975,7 +1975,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.161"
+version = "0.0.181"
 dependencies = [
  "anyhow",
  "bincode",
@@ -2028,7 +2028,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -2038,7 +2038,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -2061,7 +2061,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "bincode",
  "bitflags",
@@ -2078,7 +2078,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ahash",
  "anyhow",

flake8_to_ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "flake8-to-ruff"
-version = "0.0.161-dev.0"
+version = "0.0.181-dev.0"
 edition = "2021"
 
 [lib]

flake8_to_ruff/src/converter.rs

@@ -246,6 +246,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -257,6 +258,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -270,6 +272,7 @@ mod tests {
             flake8_bugbear: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -290,6 +293,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -301,6 +305,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: Some(100),
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -314,6 +319,7 @@ mod tests {
             flake8_bugbear: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -334,6 +340,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -345,6 +352,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: Some(100),
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -358,6 +366,7 @@ mod tests {
             flake8_bugbear: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -378,6 +387,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -389,6 +399,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -402,6 +413,7 @@ mod tests {
             flake8_bugbear: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -422,6 +434,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -433,6 +446,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -451,6 +465,7 @@ mod tests {
                 avoid_escape: None,
             }),
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -474,6 +489,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -485,6 +501,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::D100,
                 CheckCodePrefix::D101,
@@ -507,6 +524,7 @@ mod tests {
                 CheckCodePrefix::D214,
                 CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 CheckCodePrefix::D403,
                 CheckCodePrefix::D404,
@@ -533,6 +551,7 @@ mod tests {
             flake8_bugbear: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -553,6 +572,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -564,6 +584,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -583,6 +604,7 @@ mod tests {
                 avoid_escape: None,
             }),
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,

flake8_to_ruff/src/parser.rs

@@ -135,7 +135,6 @@ fn tokenize_files_to_codes_mapping(value: &str) -> Vec<Token> {
 }
 
 /// Parse a 'files-to-codes' mapping, mimicking Flake8's internal logic.
-///
 /// See: <https://github.com/PyCQA/flake8/blob/7dfe99616fc2f07c0017df2ba5fa884158f3ea8a/src/flake8/utils.py#L45>
 pub fn parse_files_to_codes_mapping(value: &str) -> Result<Vec<PatternPrefixPair>> {
     if value.trim().is_empty() {

flake8_to_ruff/src/plugin.rs

@@ -18,6 +18,7 @@ pub enum Plugin {
     Flake8Print,
     Flake8Quotes,
     Flake8Return,
+    Flake8Simplify,
     Flake8TidyImports,
     McCabe,
     PEP8Naming,
@@ -41,6 +42,7 @@ impl FromStr for Plugin {
             "flake8-print" => Ok(Plugin::Flake8Print),
             "flake8-quotes" => Ok(Plugin::Flake8Quotes),
             "flake8-return" => Ok(Plugin::Flake8Return),
+            "flake8-simplify" => Ok(Plugin::Flake8Simplify),
             "flake8-tidy-imports" => Ok(Plugin::Flake8TidyImports),
             "mccabe" => Ok(Plugin::McCabe),
             "pep8-naming" => Ok(Plugin::PEP8Naming),
@@ -65,6 +67,7 @@ impl Plugin {
             Plugin::Flake8Print => CheckCodePrefix::T2,
             Plugin::Flake8Quotes => CheckCodePrefix::Q,
             Plugin::Flake8Return => CheckCodePrefix::RET,
+            Plugin::Flake8Simplify => CheckCodePrefix::SIM,
             Plugin::Flake8TidyImports => CheckCodePrefix::I25,
             Plugin::McCabe => CheckCodePrefix::C9,
             Plugin::PEP8Naming => CheckCodePrefix::N,
@@ -101,6 +104,7 @@ impl Plugin {
             Plugin::Flake8Print => vec![CheckCodePrefix::T2],
             Plugin::Flake8Quotes => vec![CheckCodePrefix::Q],
             Plugin::Flake8Return => vec![CheckCodePrefix::RET],
+            Plugin::Flake8Simplify => vec![CheckCodePrefix::SIM],
             Plugin::Flake8TidyImports => vec![CheckCodePrefix::I25],
             Plugin::McCabe => vec![CheckCodePrefix::C9],
             Plugin::PEP8Naming => vec![CheckCodePrefix::N],
@@ -162,6 +166,7 @@ impl DocstringConvention {
                 // CheckCodePrefix::D214,
                 // CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -209,6 +214,7 @@ impl DocstringConvention {
                 CheckCodePrefix::D214,
                 CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 // CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -257,6 +263,7 @@ impl DocstringConvention {
                 CheckCodePrefix::D214,
                 // CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 // CheckCodePrefix::D400,
                 CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -394,6 +401,7 @@ pub fn infer_plugins_from_codes(codes: &BTreeSet<CheckCodePrefix>) -> Vec<Plugin
         Plugin::Flake8Print,
         Plugin::Flake8Quotes,
         Plugin::Flake8Return,
+        Plugin::Flake8Simplify,
         Plugin::Flake8TidyImports,
         Plugin::PEP8Naming,
         Plugin::Pyupgrade,

resources/test/fixtures/README.md

@@ -0,0 +1,3 @@
+# fixtures
+
+Fixture files used for snapshot testing.

resources/test/fixtures/eradicate/ERA001.py

@@ -5,9 +5,11 @@ a = 4
 #foo(1, 2, 3)
 
 def foo(x, y, z):
-    contentet = 1 # print('hello')
+    content = 1 # print('hello')
     print(x, y, z)
 
     # This is a real comment.
     #return True
     return False
+
+#import os  # noqa: ERA001

resources/test/fixtures/flake8_annotations/allow_overload.py

@@ -0,0 +1,49 @@
+from typing import overload
+
+
+@overload
+def foo(i: int) -> "int":
+    ...
+
+
+@overload
+def foo(i: "str") -> "str":
+    ...
+
+
+def foo(i):
+    return i
+
+
+@overload
+def bar(i: int) -> "int":
+    ...
+
+
+@overload
+def bar(i: "str") -> "str":
+    ...
+
+
+class X:
+    def bar(i):
+        return i
+
+
+# TODO(charlie): This third case should raise an error (as in Mypy), because we have a
+# statement between the interfaces and implementation.
+@overload
+def baz(i: int) -> "int":
+    ...
+
+
+@overload
+def baz(i: "str") -> "str":
+    ...
+
+
+x = 1
+
+
+def baz(i):
+    return i

resources/test/fixtures/flake8_blind_except/BLE.py

@@ -53,3 +53,11 @@ try:
         raise e
 except Exception:
     pass
+
+
+try:
+    pass
+except Exception as e:
+    raise bad
+except BaseException:
+    pass

resources/test/fixtures/flake8_bugbear/B009_B010.py

@@ -20,6 +20,8 @@ getattr(foo, "_123abc")
 getattr(foo, "abc123")
 getattr(foo, r"abc123")
 _ = lambda x: getattr(x, "bar")
+if getattr(x, "bar"):
+    pass
 
 # Valid setattr usage
 setattr(foo, bar, None)
@@ -28,6 +30,8 @@ setattr(foo, "123abc", None)
 setattr(foo, r"123\abc", None)
 setattr(foo, "except", None)
 _ = lambda x: setattr(x, "bar", 1)
+if setattr(x, "bar", 1):
+    pass
 
 # Invalid usage
 setattr(foo, "bar", None)

resources/test/fixtures/flake8_bugbear/B905.py

@@ -0,0 +1,10 @@
+zip()
+zip(range(3))
+zip("a", "b")
+zip("a", "b", *zip("c"))
+zip(zip("a"), strict=False)
+zip(zip("a", strict=True))
+
+zip(range(3), strict=True)
+zip("a", "b", strict=False)
+zip("a", "b", "c", strict=True)

resources/test/fixtures/flake8_import_conventions/custom.py

@@ -0,0 +1,25 @@
+import math  # not checked
+
+import altair  # unconventional
+import dask.array  # unconventional
+import dask.dataframe  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # unconventional
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import dask.array as darray  # unconventional
+import dask.dataframe as ddf  # unconventional
+import numpy as nmp  # unconventional
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import dask.array as da  # conventional
+import dask.dataframe as dd  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as np  # conventional
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_import_conventions/defaults.py

@@ -0,0 +1,19 @@
+import math  # not checked
+
+import altair  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # unconventional
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import numpy as nmp  # unconventional
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as np  # conventional
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_import_conventions/override_default.py

@@ -0,0 +1,19 @@
+import math  # not checked
+
+import altair  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # unconventional
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import numpy as np  # unconventional
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as nmp  # conventional
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_import_conventions/remove_default.py

@@ -0,0 +1,19 @@
+import math  # not checked
+
+import altair  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # not checked
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import numpy as nmp  # not checked
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as np  # not checked
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_return/RET504.py

@@ -130,6 +130,12 @@ def x():
     return val
 
 
+def x():
+    a = 1
+    print(f"a={a}")
+    return a
+
+
 # Test cases for using value for assignment then returning it
 # See:https://github.com/afonasev/flake8-return/issues/47
 def resolve_from_url(self, url: str) -> dict:

resources/test/fixtures/flake8_simplify/SIM118.py

@@ -0,0 +1,12 @@
+key in dict.keys() # SIM118
+
+foo["bar"] in dict.keys() # SIM118
+
+foo() in dict.keys() # SIM118
+
+for key in dict.keys(): # SIM118
+    pass
+
+for key in list(dict.keys()):
+    if some_property(key):
+        del dict[key]

resources/test/fixtures/flake8_unused_arguments/ARG.py

@@ -0,0 +1,137 @@
+from abc import abstractmethod
+from typing_extensions import override
+
+
+###
+# Unused arguments on functions.
+###
+def f(self, x):
+    print("Hello, world!")
+
+
+def f(cls, x):
+    print("Hello, world!")
+
+
+def f(self, x):
+    ...
+
+
+def f(cls, x):
+    ...
+
+
+###
+# Unused arguments on lambdas.
+###
+lambda x: print("Hello, world!")
+
+
+class X:
+    ###
+    # Unused arguments.
+    ###
+    def f(self, x):
+        print("Hello, world!")
+
+    def f(self, /, x):
+        print("Hello, world!")
+
+    def f(cls, x):
+        print("Hello, world!")
+
+    @classmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    def f(x):
+        print("Hello, world!")
+
+    ###
+    # Unused arguments attached to empty functions (OK).
+    ###
+    def f(self, x):
+        ...
+
+    def f(self, /, x):
+        ...
+
+    def f(cls, x):
+        ...
+
+    @classmethod
+    def f(cls, x):
+        ...
+
+    @staticmethod
+    def f(cls, x):
+        ...
+
+    @staticmethod
+    def f(x):
+        ...
+
+    ###
+    # Unused functions attached to abstract methods (OK).
+    ###
+    @abstractmethod
+    def f(self, x):
+        print("Hello, world!")
+
+    @abstractmethod
+    def f(self, /, x):
+        print("Hello, world!")
+
+    @abstractmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @classmethod
+    @abstractmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @abstractmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @abstractmethod
+    def f(x):
+        print("Hello, world!")
+
+    ###
+    # Unused functions attached to overrides (OK).
+    ###
+    @override
+    def f(self, x):
+        print("Hello, world!")
+
+    @override
+    def f(self, /, x):
+        print("Hello, world!")
+
+    @override
+    def f(cls, x):
+        print("Hello, world!")
+
+    @classmethod
+    @override
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @override
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @override
+    def f(x):
+        print("Hello, world!")

resources/test/fixtures/isort/insert_empty_lines.py

@@ -14,3 +14,52 @@ y = 1
 import os
 import sys
 """Docstring"""
+
+if True:
+    import os
+
+
+def f():
+    pass
+
+
+if True:
+    import os
+def f():
+    pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    class X: pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    def f(): pass
+
+
+import os
+
+# Comment goes here.
+
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+
+# And another.
+def f():
+    pass

resources/test/fixtures/isort/insert_empty_lines.pyi

@@ -0,0 +1,65 @@
+import a
+import b
+x = 1
+import os
+import sys
+def f():
+    pass
+if True:
+    x = 1
+    import collections
+    import typing
+class X: pass
+y = 1
+import os
+import sys
+"""Docstring"""
+
+if True:
+    import os
+
+
+def f():
+    pass
+
+
+if True:
+    import os
+def f():
+    pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    class X: pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    def f(): pass
+
+
+import os
+
+# Comment goes here.
+
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+
+# And another.
+def f():
+    pass

resources/test/fixtures/isort/no_wrap_star.py

@@ -0,0 +1 @@
+from .subscription import * # type: ignore  # some very long comment explaining why this needs a type ignore

resources/test/fixtures/pydocstyle/D.py

@@ -571,3 +571,11 @@ def multiline_trailing_and_leading_space():
     """
 
     pass
+
+
+@expect('D210: No whitespaces allowed surrounding docstring text')
+@expect("D400: First line should end with a period (not '\"')")
+@expect("D415: First line should end with a period, question mark, "
+        "or exclamation point (not '\"')")
+def endswith_quote():
+    """Whitespace at the end, but also a quote" """

resources/test/fixtures/pydocstyle/D400.py

@@ -0,0 +1,73 @@
+def f():
+    "Here's a line without a period"
+    ...
+
+
+def f():
+    """Here's a line without a period"""
+    ...
+
+
+def f():
+    """
+    Here's a line without a period,
+    but here's the next line
+    """
+    ...
+
+
+def f():
+    """Here's a line without a period"""
+    ...
+
+
+def f():
+    """
+    Here's a line without a period,
+    but here's the next line"""
+    ...
+
+
+def f():
+    """
+    Here's a line without a period,
+    but here's the next line with trailing space """
+    ...
+
+
+
+def f():
+    r"Here's a line without a period"
+    ...
+
+
+def f():
+    r"""Here's a line without a period"""
+    ...
+
+
+def f():
+    r"""
+    Here's a line without a period,
+    but here's the next line
+    """
+    ...
+
+
+def f():
+    r"""Here's a line without a period"""
+    ...
+
+
+def f():
+    r"""
+    Here's a line without a period,
+    but here's the next line"""
+    ...
+
+
+def f():
+    r"""
+    Here's a line without a period,
+    but here's the next line with trailing space """
+    ...

resources/test/fixtures/pyflakes/F504.py

@@ -4,3 +4,6 @@ a = "wrong"
 
 hidden = {"a": "!"}
 "%(a)s %(c)s" % {"x": 1, **hidden}  # Ok (cannot see through splat)
+
+"%(a)s" % {"a": 1, r"b": "!"}  # F504 ("b" not used)
+"%(a)s" % {'a': 1, u"b": "!"}  # F504 ("b" not used)

resources/test/fixtures/pyflakes/F541.py

@@ -9,3 +9,4 @@ e = (
 )
 
 g = f"ghi{123:{45}}"
+h = "x" "y" f"z"

resources/test/fixtures/pyflakes/F811_0.py

@@ -0,0 +1,11 @@
+def foo(x):
+    return x
+
+
+@foo
+def bar():
+    pass
+
+
+def bar():
+    pass

resources/test/fixtures/pyflakes/F811_1.py

@@ -0,0 +1 @@
+import fu as FU, bar as FU

resources/test/fixtures/pyflakes/F811_10.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice using a nested does not issue a warning."""
+try:
+    if True:
+        if True:
+            import os
+except:
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_11.py

@@ -0,0 +1,9 @@
+try:
+    from aa import mixer
+except AttributeError:
+    from bb import mixer
+except RuntimeError:
+    from cc import mixer
+except:
+    from dd import mixer
+mixer(123)

resources/test/fixtures/pyflakes/F811_12.py

@@ -0,0 +1,7 @@
+try:
+    from aa import mixer
+except ImportError:
+    pass
+else:
+    from bb import mixer
+mixer(123)

resources/test/fixtures/pyflakes/F811_13.py

@@ -0,0 +1,8 @@
+try:
+    import funca
+except ImportError:
+    from bb import funca
+    from bb import funcb
+else:
+    from bbb import funcb
+print(funca, funcb)

resources/test/fixtures/pyflakes/F811_14.py

@@ -0,0 +1,10 @@
+try:
+    import b
+except ImportError:
+    b = Ellipsis
+    from bb import a
+else:
+    from aa import a
+finally:
+    a = 42
+print(a, b)

resources/test/fixtures/pyflakes/F811_15.py

@@ -0,0 +1,5 @@
+import fu
+
+
+def fu():
+    pass

resources/test/fixtures/pyflakes/F811_16.py

@@ -0,0 +1,9 @@
+"""Test that shadowing a global with a nested function generates a warning."""
+
+import fu
+
+
+def bar():
+    def baz():
+        def fu():
+            pass

resources/test/fixtures/pyflakes/F811_17.py

@@ -0,0 +1,10 @@
+"""Test that shadowing a global name with a nested function generates a warning."""
+import fu
+
+
+def bar():
+    import fu
+
+    def baz():
+        def fu():
+            pass

resources/test/fixtures/pyflakes/F811_18.py

@@ -0,0 +1,14 @@
+"""Test that a global import which is redefined locally, but used later in another scope does not generate a warning."""
+
+import unittest, transport
+
+
+class GetTransportTestCase(unittest.TestCase):
+    def test_get_transport(self):
+        transport = 'transport'
+        self.assertIsNotNone(transport)
+
+
+class TestTransportMethodArgs(unittest.TestCase):
+    def test_send_defaults(self):
+        transport.Transport()

resources/test/fixtures/pyflakes/F811_19.py

@@ -0,0 +1,7 @@
+"""If an imported name is redefined by a class statement which also uses that name in the bases list, no warning is emitted."""
+
+from fu import bar
+
+
+class bar(bar):
+    pass

resources/test/fixtures/pyflakes/F811_2.py

@@ -0,0 +1 @@
+from moo import fu as FU, bar as FU

resources/test/fixtures/pyflakes/F811_20.py

@@ -0,0 +1,14 @@
+"""
+ Test that shadowing a global with a class attribute does not produce a
+ warning.
+ """
+
+import fu
+
+
+class bar:
+    # STOPSHIP: This errors.
+    fu = 1
+
+
+print(fu)

resources/test/fixtures/pyflakes/F811_3.py

@@ -0,0 +1 @@
+import fu; fu = 3

resources/test/fixtures/pyflakes/F811_4.py

@@ -0,0 +1 @@
+import fu; fu, bar = 3

resources/test/fixtures/pyflakes/F811_5.py

@@ -0,0 +1 @@
+import fu; [fu, bar] = 3

resources/test/fixtures/pyflakes/F811_6.py

@@ -0,0 +1,7 @@
+"""Test that importing a module twice within an if block does raise a warning."""
+
+i = 2
+if i == 1:
+    import os
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_7.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice in if-else blocks does not raise a warning."""
+
+i = 2
+if i == 1:
+    import os
+else:
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_8.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice in a try block does raise a warning."""
+
+try:
+    import os
+    import os
+except:
+    pass
+os.path

resources/test/fixtures/pyflakes/F811_9.py

@@ -0,0 +1,7 @@
+"""Test that importing a module twice in a try block does not raise a warning."""
+
+try:
+    import os
+except:
+    import os
+os.path

resources/test/fixtures/pyflakes/F821_6.py

@@ -0,0 +1,17 @@
+"""Test: annotated global."""
+
+
+n: int
+
+
+def f():
+    print(n)
+
+
+def g():
+    global n
+    n = 1
+
+
+g()
+f()

resources/test/fixtures/pyflakes/F841_0.py

@@ -10,13 +10,13 @@ except ValueError as e:
     print(e)
 
 
-def f1():
+def f():
     x = 1
     y = 2
     z = x + y
 
 
-def f2():
+def f():
     foo = (1, 2)
     (a, b) = (1, 2)
 
@@ -26,12 +26,12 @@ def f2():
     (x, y) = baz = bar
 
 
-def f3():
+def f():
     locals()
     x = 1
 
 
-def f4():
+def f():
     _ = 1
     __ = 1
     _discarded = 1
@@ -40,28 +40,49 @@ def f4():
 a = 1
 
 
-def f5():
+def f():
     global a
 
-    # Used in `f7` via `nonlocal`.
+    # Used in `c` via `nonlocal`.
     b = 1
 
-    def f6():
+    def c():
         # F841
         b = 1
 
-    def f7():
+    def d():
         nonlocal b
 
 
-def f6():
+def f():
     annotations = []
     assert len([annotations for annotations in annotations])
 
 
-def f7():
+def f():
     def connect():
         return None, None
 
     with connect() as (connection, cursor):
         cursor.execute("SELECT * FROM users")
+
+
+def f():
+    def connect():
+        return None, None
+
+    with (connect() as (connection, cursor)):
+        cursor.execute("SELECT * FROM users")
+
+
+def f():
+    with open("file") as my_file, open("") as ((this, that)):
+        print("hello")
+
+
+def f():
+    with (
+        open("file") as my_file,
+        open("") as ((this, that)),
+    ):
+        print("hello")

resources/test/fixtures/pyflakes/F841_1.py

@@ -0,0 +1,24 @@
+def f(tup):
+    x, y = tup  # this does NOT trigger F841
+
+
+def f():
+    x, y = 1, 2  # this triggers F841 as it's just a simple assignment where unpacking isn't needed
+
+
+def f():
+    (x, y) = coords = 1, 2  # this does NOT trigger F841
+    if x > 1:
+        print(coords)
+
+
+def f():
+    (x, y) = coords = 1, 2  # this triggers F841 on coords
+
+
+def f():
+    coords = (x, y) = 1, 2  # this triggers F841 on coords
+
+
+def f():
+    (a, b) = (x, y) = 1, 2  # this triggers F841 on everything

resources/test/fixtures/pyflakes/F842.py

@@ -0,0 +1,13 @@
+def f():
+    name: str
+    age: int
+
+
+class A:
+    name: str
+    age: int
+
+
+class B:
+    name: str = "Bob"
+    age: int = 18

resources/test/fixtures/pylint/global_variable_not_assigned.py

@@ -0,0 +1,32 @@
+###
+# Errors.
+###
+def f():
+    global x
+
+
+def f():
+    global x
+
+    print(x)
+
+
+###
+# Non-errors.
+###
+def f():
+    global x
+
+    x = 1
+
+
+def f():
+    global x
+
+    (x, y) = (1, 2)
+
+
+def f():
+    global x
+
+    del x

resources/test/fixtures/pylint/nonlocal_without_binding.py

@@ -0,0 +1,19 @@
+nonlocal x
+
+
+def f():
+    nonlocal x
+
+
+def f():
+    nonlocal y
+
+
+def f():
+    x = 1
+
+    def f():
+        nonlocal x
+
+    def f():
+        nonlocal y

resources/test/fixtures/pylint/used_prior_global_declaration.py

@@ -0,0 +1,148 @@
+###
+# Errors.
+###
+def f():
+    print(x)
+
+    global x
+
+    print(x)
+
+
+def f():
+    global x
+
+    print(x)
+
+    global x
+
+    print(x)
+
+
+def f():
+    print(x)
+
+    global x, y
+
+    print(x)
+
+
+def f():
+    global x, y
+
+    print(x)
+
+    global x, y
+
+    print(x)
+
+
+def f():
+    x = 1
+
+    global x
+
+    x = 1
+
+
+def f():
+    global x
+
+    x = 1
+
+    global x
+
+    x = 1
+
+
+def f():
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    del x
+
+    global x
+
+    del x
+
+
+def f():
+    global x
+
+    del x
+
+    global x
+
+    del x
+
+
+def f():
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x
+
+    global x, y
+
+    del x
+
+
+###
+# Non-errors.
+###
+def f():
+    global x
+
+    print(x)
+
+
+def f():
+    global x, y
+
+    print(x)
+
+
+def f():
+    global x
+
+    x = 1
+
+
+def f():
+    global x, y
+
+    x = 1
+
+
+def f():
+    global x
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x

resources/test/fixtures/pylint/useless_else_on_loop.py

@@ -75,7 +75,7 @@ def test_break_in_orelse_deep():
 
 
 def test_break_in_orelse_deep2():
-    """should rise a useless-else-on-loop message, as the break statement is only
+    """should raise a useless-else-on-loop message, as the break statement is only
     for the inner for loop
     """
     for _ in range(10):
@@ -101,3 +101,15 @@ def test_break_in_orelse_deep3():
     else:
         return True
     return False
+
+
+def test_break_in_if_orelse():
+    """should raise a useless-else-on-loop message due to break in else"""
+    for _ in range(10):
+        if 1 < 2:  # pylint: disable=comparison-of-constants
+            pass
+        else:
+            break
+    else:
+        return True
+    return False

resources/test/fixtures/pyproject.toml

@@ -41,3 +41,9 @@ staticmethod-decorators = ["staticmethod"]
 
 [tool.ruff.flake8-tidy-imports]
 ban-relative-imports = "parents"
+
+[tool.ruff.flake8-import-conventions.aliases]
+pandas = "pd"
+
+[tool.ruff.flake8-import-conventions.extend-aliases]
+"dask.dataframe" = "dd"

resources/test/project/.gitignore

@@ -0,0 +1 @@
+examples/generated

resources/test/project/README.md

@@ -0,0 +1,90 @@
+# project
+
+An example multi-package Python project used to test setting resolution and other complex
+behaviors.
+
+## Expected behavior
+
+Running from the repo root should pick up and enforce the appropriate settings for each package:
+
+```
+∴ cargo run resources/test/project/
+Found 7 error(s).
+resources/test/project/examples/.dotfiles/script.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/.dotfiles/script.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/examples/docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+resources/test/project/examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/file.py:1:8: F401 `os` imported but unused
+resources/test/project/src/file.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+4 potentially fixable with the --fix option.
+```
+
+Running from the project directory itself should exhibit the same behavior:
+
+```
+∴ (cd resources/test/project/ && cargo run .)
+Found 7 error(s).
+examples/.dotfiles/script.py:1:8: F401 `os` imported but unused
+examples/.dotfiles/script.py:5:5: F841 Local variable `x` is assigned to but never used
+examples/docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+src/file.py:1:8: F401 `os` imported but unused
+src/file.py:5:5: F841 Local variable `x` is assigned to but never used
+src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+4 potentially fixable with the --fix option.
+```
+
+Running from the sub-package directory should exhibit the same behavior, but omit the top-level
+files:
+
+```
+∴ (cd resources/test/project/examples/docs && cargo run .)
+Found 2 error(s).
+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
+1 potentially fixable with the --fix option.
+```
+
+`--config` should force Ruff to use the specified `pyproject.toml` for all files, and resolve
+file paths from the current working directory:
+
+```
+∴ (cargo run -- --config=resources/test/project/pyproject.toml resources/test/project/)
+Found 11 error(s).
+resources/test/project/examples/.dotfiles/script.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/.dotfiles/script.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/examples/docs/docs/concepts/file.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/docs/docs/concepts/file.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/examples/docs/docs/file.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/docs/docs/file.py:3:8: F401 `numpy` imported but unused
+resources/test/project/examples/docs/docs/file.py:4:27: F401 `docs.concepts.file` imported but unused
+resources/test/project/examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/file.py:1:8: F401 `os` imported but unused
+resources/test/project/src/file.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+7 potentially fixable with the --fix option.
+```
+
+Running from a parent directory should this "ignore" the `exclude` (hence, `concepts/file.py` gets
+included in the output):
+
+```
+∴ (cd resources/test/project/examples && cargo run -- --config=docs/pyproject.toml .)
+Found 4 error(s).
+.dotfiles/script.py:5:5: F841 Local variable `x` is assigned to but never used
+docs/docs/concepts/file.py:5:5: F841 Local variable `x` is assigned to but never used
+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
+1 potentially fixable with the --fix option.
+```
+
+Passing an excluded directory directly should report errors in the contained files:
+
+```
+∴ cargo run resources/test/project/examples/excluded/
+Found 2 error(s).
+resources/test/project/examples/excluded/script.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/excluded/script.py:5:5: F841 Local variable `x` is assigned to but never used
+1 potentially fixable with the --fix option.
+```

resources/test/project/examples/.dotfiles/script.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/examples/docs/docs/concepts/file.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/examples/docs/docs/file.py

@@ -0,0 +1,8 @@
+import os
+
+import numpy as np
+from docs.concepts import file
+
+
+def f():
+    x = 1

resources/test/project/examples/docs/pyproject.toml

@@ -0,0 +1,6 @@
+[tool.ruff]
+extend = "../../pyproject.toml"
+src = ["."]
+extend-select = ["I001"]
+extend-ignore = ["F401"]
+extend-exclude = ["./docs/concepts/file.py"]

resources/test/project/examples/excluded/script.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/pyproject.toml

@@ -0,0 +1,4 @@
+[tool.ruff]
+src = [".", "python_modules/*"]
+exclude = ["examples/excluded"]
+extend-select = ["I001"]

resources/test/project/src/file.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/src/import_file.py

@@ -0,0 +1,7 @@
+import numpy as np
+from app import app_file
+from core import core_file
+
+np.array([1, 2, 3])
+app_file()
+core_file()

ruff_dev/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_dev"
-version = "0.0.161"
+version = "0.0.181"
 edition = "2021"
 
 [dependencies]
@@ -11,8 +11,8 @@ itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
 once_cell = { version = "1.16.0" }
 ruff = { path = ".." }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
 strum_macros = { version = "0.24.3" }

ruff_dev/src/generate_check_code_prefix.rs

@@ -8,7 +8,7 @@ use anyhow::Result;
 use clap::Parser;
 use codegen::{Scope, Type, Variant};
 use itertools::Itertools;
-use ruff::checks::{CheckCode, REDIRECTS};
+use ruff::checks::{CheckCode, CODE_REDIRECTS, PREFIX_REDIRECTS};
 use strum::IntoEnumIterator;
 
 const FILE: &str = "src/checks_gen.rs";
@@ -39,34 +39,26 @@ pub fn main(cli: &Cli) -> Result<()> {
         }
     }
 
-    // Add any aliases (e.g., "U001" to "UP001").
-    for (alias, check_code) in REDIRECTS.iter() {
-        // Compute the length of the prefix and suffix for both codes.
-        let code_str: String = check_code.as_ref().to_string();
-        let code_prefix_len = code_str
-            .chars()
-            .take_while(|char| char.is_alphabetic())
-            .count();
-        let code_suffix_len = code_str.len() - code_prefix_len;
-        let alias_prefix_len = alias
-            .chars()
-            .take_while(|char| char.is_alphabetic())
-            .count();
-        let alias_suffix_len = alias.len() - alias_prefix_len;
-        assert_eq!(code_suffix_len, alias_suffix_len);
-        for i in 0..=code_suffix_len {
-            let source = code_str[..code_prefix_len + i].to_string();
-            let destination = alias[..alias_prefix_len + i].to_string();
-            if source != destination {
-                prefix_to_codes.insert(
-                    destination,
-                    prefix_to_codes
-                        .get(&source)
-                        .unwrap_or_else(|| panic!("Unknown CheckCode: {source:?}"))
-                        .clone(),
-                );
-            }
-        }
+    // Add any prefix aliases (e.g., "U" to "UP").
+    for (alias, source) in PREFIX_REDIRECTS.iter() {
+        prefix_to_codes.insert(
+            (*alias).to_string(),
+            prefix_to_codes
+                .get(&(*source).to_string())
+                .unwrap_or_else(|| panic!("Unknown CheckCode: {source:?}"))
+                .clone(),
+        );
+    }
+
+    // Add any check code aliases (e.g., "U001" to "UP001").
+    for (alias, check_code) in CODE_REDIRECTS.iter() {
+        prefix_to_codes.insert(
+            (*alias).to_string(),
+            prefix_to_codes
+                .get(&check_code.as_ref().to_string())
+                .unwrap_or_else(|| panic!("Unknown CheckCode: {alias:?}"))
+                .clone(),
+        );
     }
 
     let mut scope = Scope::new();
@@ -76,6 +68,7 @@ pub fn main(cli: &Cli) -> Result<()> {
         .new_enum("CheckCodePrefix")
         .vis("pub")
         .derive("EnumString")
+        .derive("AsRefStr")
         .derive("Debug")
         .derive("PartialEq")
         .derive("Eq")
@@ -112,10 +105,10 @@ pub fn main(cli: &Cli) -> Result<()> {
         .line("#[allow(clippy::match_same_arms)]")
         .line("match self {");
     for (prefix, codes) in &prefix_to_codes {
-        if let Some(target) = REDIRECTS.get(&prefix.as_str()) {
+        if let Some(target) = CODE_REDIRECTS.get(&prefix.as_str()) {
             gen = gen.line(format!(
                 "CheckCodePrefix::{prefix} => {{ eprintln!(\"{{}}{{}} {{}}\", \
-                 \"warning\".yellow().bold(), \":\".bold(), \"`{}` has been renamed to \
+                 \"warning\".yellow().bold(), \":\".bold(), \"`{}` has been remapped to \
                  `{}`\".bold()); \n vec![{}] }}",
                 prefix,
                 target.as_ref(),
@@ -124,6 +117,18 @@ pub fn main(cli: &Cli) -> Result<()> {
                     .map(|code| format!("CheckCode::{}", code.as_ref()))
                     .join(", ")
             ));
+        } else if let Some(target) = PREFIX_REDIRECTS.get(&prefix.as_str()) {
+            gen = gen.line(format!(
+                "CheckCodePrefix::{prefix} => {{ eprintln!(\"{{}}{{}} {{}}\", \
+                 \"warning\".yellow().bold(), \":\".bold(), \"`{}` has been remapped to \
+                 `{}`\".bold()); \n vec![{}] }}",
+                prefix,
+                target,
+                codes
+                    .iter()
+                    .map(|code| format!("CheckCode::{}", code.as_ref()))
+                    .join(", ")
+            ));
         } else {
             gen = gen.line(format!(
                 "CheckCodePrefix::{prefix} => vec![{}],",
@@ -170,9 +175,9 @@ pub fn main(cli: &Cli) -> Result<()> {
     output.push('\n');
     output.push_str("use colored::Colorize;");
     output.push('\n');
-    output.push_str("use serde::{{Serialize, Deserialize}};");
+    output.push_str("use serde::{Deserialize, Serialize};");
     output.push('\n');
-    output.push_str("use strum_macros::EnumString;");
+    output.push_str("use strum_macros::{AsRefStr, EnumString};");
     output.push('\n');
     output.push('\n');
     output.push_str("use crate::checks::CheckCode;");
@@ -186,7 +191,9 @@ pub fn main(cli: &Cli) -> Result<()> {
     output.push_str("pub const CATEGORIES: &[CheckCodePrefix] = &[");
     output.push('\n');
     for prefix in prefix_to_codes.keys() {
-        if prefix.chars().all(char::is_alphabetic) {
+        if prefix.chars().all(char::is_alphabetic)
+            && !PREFIX_REDIRECTS.contains_key(&prefix.as_str())
+        {
             output.push_str(&format!("CheckCodePrefix::{prefix},"));
             output.push('\n');
         }

ruff_dev/src/generate_options.rs

@@ -0,0 +1,125 @@
+//! Generate a Markdown-compatible listing of configuration options.
+
+use std::fs;
+use std::fs::OpenOptions;
+use std::io::Write;
+use std::path::PathBuf;
+
+use anyhow::Result;
+use clap::Args;
+use itertools::Itertools;
+use ruff::settings::options::Options;
+use ruff::settings::options_base::{ConfigurationOptions, OptionEntry, OptionField};
+
+const BEGIN_PRAGMA: &str = "<!-- Begin auto-generated options sections. -->";
+const END_PRAGMA: &str = "<!-- End auto-generated options sections. -->";
+
+#[derive(Args)]
+pub struct Cli {
+    /// Write the generated table to stdout (rather than to `README.md`).
+    #[arg(long)]
+    dry_run: bool,
+}
+
+fn emit_field(output: &mut String, field: &OptionField, group_name: Option<&str>) {
+    output.push_str(&format!("#### [`{0}`](#{0})\n", field.name));
+    output.push('\n');
+    output.push_str(field.doc);
+    output.push_str("\n\n");
+    output.push_str(&format!("**Default value**: `{}`\n", field.default));
+    output.push('\n');
+    output.push_str(&format!("**Type**: `{}`\n", field.value_type));
+    output.push('\n');
+    output.push_str(&format!(
+        "**Example usage**:\n\n```toml\n[tool.ruff{}]\n{}\n```\n",
+        if group_name.is_some() {
+            format!(".{}", group_name.unwrap())
+        } else {
+            String::new()
+        },
+        field.example
+    ));
+    output.push('\n');
+}
+
+pub fn main(cli: &Cli) -> Result<()> {
+    let mut output = String::new();
+
+    // Generate all the top-level fields.
+    for field in Options::get_available_options()
+        .into_iter()
+        .filter_map(|entry| {
+            if let OptionEntry::Field(field) = entry {
+                Some(field)
+            } else {
+                None
+            }
+        })
+        .sorted_by_key(|field| field.name)
+    {
+        emit_field(&mut output, &field, None);
+        output.push_str("---\n\n");
+    }
+
+    // Generate all the sub-groups.
+    for group in Options::get_available_options()
+        .into_iter()
+        .filter_map(|entry| {
+            if let OptionEntry::Group(group) = entry {
+                Some(group)
+            } else {
+                None
+            }
+        })
+        .sorted_by_key(|group| group.name)
+    {
+        output.push_str(&format!("### `{}`\n", group.name));
+        output.push('\n');
+        for field in group
+            .fields
+            .iter()
+            .filter_map(|entry| {
+                if let OptionEntry::Field(field) = entry {
+                    Some(field)
+                } else {
+                    None
+                }
+            })
+            .sorted_by_key(|field| field.name)
+        {
+            emit_field(&mut output, field, Some(group.name));
+            output.push_str("---\n\n");
+        }
+    }
+
+    if cli.dry_run {
+        print!("{output}");
+    } else {
+        // Read the existing file.
+        let file = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+            .parent()
+            .expect("Failed to find root directory")
+            .join("README.md");
+        let existing = fs::read_to_string(&file)?;
+
+        // Extract the prefix.
+        let index = existing
+            .find(BEGIN_PRAGMA)
+            .expect("Unable to find begin pragma");
+        let prefix = &existing[..index + BEGIN_PRAGMA.len()];
+
+        // Extract the suffix.
+        let index = existing
+            .find(END_PRAGMA)
+            .expect("Unable to find end pragma");
+        let suffix = &existing[index..];
+
+        // Write the prefix, new contents, and suffix.
+        let mut f = OpenOptions::new().write(true).truncate(true).open(&file)?;
+        write!(f, "{prefix}\n\n")?;
+        write!(f, "{output}")?;
+        write!(f, "{suffix}")?;
+    }
+
+    Ok(())
+}

ruff_dev/src/generate_rules_table.rs

@@ -7,11 +7,15 @@ use std::path::PathBuf;
 
 use anyhow::Result;
 use clap::Args;
+use itertools::Itertools;
 use ruff::checks::{CheckCategory, CheckCode};
 use strum::IntoEnumIterator;
 
-const BEGIN_PRAGMA: &str = "<!-- Begin auto-generated sections. -->";
-const END_PRAGMA: &str = "<!-- End auto-generated sections. -->";
+const TABLE_BEGIN_PRAGMA: &str = "<!-- Begin auto-generated sections. -->";
+const TABLE_END_PRAGMA: &str = "<!-- End auto-generated sections. -->";
+
+const TOC_BEGIN_PRAGMA: &str = "<!-- Begin auto-generated table of contents. -->";
+const TOC_END_PRAGMA: &str = "<!-- End auto-generated table of contents. -->";
 
 #[derive(Args)]
 pub struct Cli {
@@ -22,73 +26,91 @@ pub struct Cli {
 
 pub fn main(cli: &Cli) -> Result<()> {
     // Generate the table string.
-    let mut output = String::new();
+    let mut table_out = String::new();
+    let mut toc_out = String::new();
     for check_category in CheckCategory::iter() {
-        output.push_str(&format!("### {}", check_category.title()));
-        output.push('\n');
-        output.push('\n');
+        let codes_csv: String = check_category.codes().iter().map(AsRef::as_ref).join(", ");
+        table_out.push_str(&format!("### {} ({codes_csv})", check_category.title()));
+        table_out.push('\n');
+        table_out.push('\n');
+
+        toc_out.push_str(&format!(
+            "   1. [{} ({})](#{}-{})\n",
+            check_category.title(),
+            codes_csv,
+            check_category.title().to_lowercase().replace(' ', "-"),
+            codes_csv.to_lowercase().replace(',', "-").replace(' ', "")
+        ));
 
         if let Some((url, platform)) = check_category.url() {
-            output.push_str(&format!(
+            table_out.push_str(&format!(
                 "For more, see [{}]({}) on {}.",
                 check_category.title(),
                 url,
                 platform
             ));
-            output.push('\n');
-            output.push('\n');
+            table_out.push('\n');
+            table_out.push('\n');
         }
 
-        output.push_str("| Code | Name | Message | Fix |");
-        output.push('\n');
-        output.push_str("| ---- | ---- | ------- | --- |");
-        output.push('\n');
+        table_out.push_str("| Code | Name | Message | Fix |");
+        table_out.push('\n');
+        table_out.push_str("| ---- | ---- | ------- | --- |");
+        table_out.push('\n');
 
         for check_code in CheckCode::iter() {
             if check_code.category() == check_category {
                 let check_kind = check_code.kind();
                 let fix_token = if check_kind.fixable() { "🛠" } else { "" };
-                output.push_str(&format!(
+                table_out.push_str(&format!(
                     "| {} | {} | {} | {} |",
                     check_kind.code().as_ref(),
                     check_kind.as_ref(),
                     check_kind.summary().replace('|', r"\|"),
                     fix_token
                 ));
-                output.push('\n');
+                table_out.push('\n');
             }
         }
-        output.push('\n');
+        table_out.push('\n');
     }
 
     if cli.dry_run {
-        print!("{output}");
+        print!("Table of Contents: {toc_out}\n Rules Tables: {table_out}");
     } else {
-        // Read the existing file.
-        let file = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-            .parent()
-            .expect("Failed to find root directory")
-            .join("README.md");
-        let existing = fs::read_to_string(&file)?;
-
-        // Extract the prefix.
-        let index = existing
-            .find(BEGIN_PRAGMA)
-            .expect("Unable to find begin pragma");
-        let prefix = &existing[..index + BEGIN_PRAGMA.len()];
-
-        // Extract the suffix.
-        let index = existing
-            .find(END_PRAGMA)
-            .expect("Unable to find end pragma");
-        let suffix = &existing[index..];
-
-        // Write the prefix, new contents, and suffix.
-        let mut f = OpenOptions::new().write(true).truncate(true).open(&file)?;
-        write!(f, "{prefix}\n\n")?;
-        write!(f, "{output}")?;
-        write!(f, "{suffix}")?;
+        // Extra newline in the markdown numbered list looks weird
+        replace_readme_section(toc_out.trim_end(), TOC_BEGIN_PRAGMA, TOC_END_PRAGMA)?;
+        replace_readme_section(&table_out, TABLE_BEGIN_PRAGMA, TABLE_END_PRAGMA)?;
     }
 
     Ok(())
 }
+
+fn replace_readme_section(content: &str, begin_pragma: &str, end_pragma: &str) -> Result<()> {
+    // Read the existing file.
+    let file = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .parent()
+        .expect("Failed to find root directory")
+        .join("README.md");
+    let existing = fs::read_to_string(&file)?;
+
+    // Extract the prefix.
+    let index = existing
+        .find(begin_pragma)
+        .expect("Unable to find begin pragma");
+    let prefix = &existing[..index + begin_pragma.len()];
+
+    // Extract the suffix.
+    let index = existing
+        .find(end_pragma)
+        .expect("Unable to find end pragma");
+    let suffix = &existing[index..];
+
+    // Write the prefix, new contents, and suffix.
+    let mut f = OpenOptions::new().write(true).truncate(true).open(&file)?;
+    writeln!(f, "{prefix}")?;
+    write!(f, "{content}")?;
+    write!(f, "{suffix}")?;
+
+    Ok(())
+}

ruff_dev/src/lib.rs

@@ -12,6 +12,7 @@
 )]
 
 pub mod generate_check_code_prefix;
+pub mod generate_options;
 pub mod generate_rules_table;
 pub mod generate_source_code;
 pub mod print_ast;

ruff_dev/src/main.rs

@@ -14,8 +14,8 @@
 use anyhow::Result;
 use clap::{Parser, Subcommand};
 use ruff_dev::{
-    generate_check_code_prefix, generate_rules_table, generate_source_code, print_ast, print_cst,
-    print_tokens,
+    generate_check_code_prefix, generate_options, generate_rules_table, generate_source_code,
+    print_ast, print_cst, print_tokens,
 };
 
 #[derive(Parser)]
@@ -32,6 +32,8 @@ enum Commands {
     GenerateCheckCodePrefix(generate_check_code_prefix::Cli),
     /// Generate a Markdown-compatible table of supported lint rules.
     GenerateRulesTable(generate_rules_table::Cli),
+    /// Generate a Markdown-compatible listing of configuration options.
+    GenerateOptions(generate_options::Cli),
     /// Run round-trip source code generation on a given Python file.
     GenerateSourceCode(generate_source_code::Cli),
     /// Print the AST for a given Python file.
@@ -48,6 +50,7 @@ fn main() -> Result<()> {
         Commands::GenerateCheckCodePrefix(args) => generate_check_code_prefix::main(args)?,
         Commands::GenerateRulesTable(args) => generate_rules_table::main(args)?,
         Commands::GenerateSourceCode(args) => generate_source_code::main(args)?,
+        Commands::GenerateOptions(args) => generate_options::main(args)?,
         Commands::PrintAST(args) => print_ast::main(args)?,
         Commands::PrintCST(args) => print_cst::main(args)?,
         Commands::PrintTokens(args) => print_tokens::main(args)?,

ruff_macros/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "ruff_macros"
+version = "0.0.181"
+edition = "2021"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = { version = "1.0.47" }
+quote = { version = "1.0.21" }
+syn = { version = "1.0.103", features = ["derive", "parsing"] }
+textwrap = { version = "0.16.0" }

ruff_macros/src/lib.rs

@@ -0,0 +1,177 @@
+#![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
+)]
+
+use quote::{quote, quote_spanned};
+use syn::parse::{Parse, ParseStream};
+use syn::token::Comma;
+use syn::{
+    parse_macro_input, AngleBracketedGenericArguments, Attribute, Data, DataStruct, DeriveInput,
+    Field, Fields, Lit, LitStr, Path, PathArguments, PathSegment, Token, Type, TypePath,
+};
+
+#[proc_macro_derive(ConfigurationOptions, attributes(option, option_group))]
+pub fn derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+
+    derive_impl(input)
+        .unwrap_or_else(syn::Error::into_compile_error)
+        .into()
+}
+
+fn derive_impl(input: DeriveInput) -> syn::Result<proc_macro2::TokenStream> {
+    let DeriveInput { ident, data, .. } = input;
+
+    match data {
+        Data::Struct(DataStruct {
+            fields: Fields::Named(fields),
+            ..
+        }) => {
+            let mut output = vec![];
+
+            for field in fields.named.iter() {
+                if let Some(attr) = field.attrs.iter().find(|a| a.path.is_ident("option")) {
+                    output.push(handle_option(field, attr)?);
+                };
+
+                if field.attrs.iter().any(|a| a.path.is_ident("option_group")) {
+                    output.push(handle_option_group(field)?);
+                };
+            }
+
+            Ok(quote! {
+              use crate::settings::options_base::{OptionEntry, OptionField, OptionGroup, ConfigurationOptions};
+
+              #[automatically_derived]
+              impl ConfigurationOptions for #ident {
+                  fn get_available_options() -> Vec<OptionEntry> {
+                      vec![#(#output),*]
+                  }
+              }
+            })
+        }
+        _ => Err(syn::Error::new(
+            ident.span(),
+            "Can only derive ConfigurationOptions from structs with named fields.",
+        )),
+    }
+}
+
+/// For a field with type `Option<Foobar>` where `Foobar` itself is a struct
+/// deriving `ConfigurationOptions`, create code that calls retrieves options
+/// from that group: `Foobar::get_available_options()`
+fn handle_option_group(field: &Field) -> syn::Result<proc_macro2::TokenStream> {
+    // unwrap is safe because we're only going over named fields
+    let ident = field.ident.as_ref().unwrap();
+
+    match &field.ty {
+        Type::Path(TypePath {
+            path: Path { segments, .. },
+            ..
+        }) => match segments.first() {
+            Some(PathSegment {
+                ident: type_ident,
+                arguments:
+                    PathArguments::AngleBracketed(AngleBracketedGenericArguments { args, .. }),
+                ..
+            }) if type_ident == "Option" => {
+                let path = &args[0];
+                let kebab_name = LitStr::new(&ident.to_string().replace('_', "-"), ident.span());
+
+                Ok(quote_spanned!(
+                    ident.span() => OptionEntry::Group(OptionGroup {
+                        name: #kebab_name,
+                        fields: #path::get_available_options(),
+                    })
+                ))
+            }
+            _ => Err(syn::Error::new(
+                ident.span(),
+                "Expected `Option<_>`  as type.",
+            )),
+        },
+        _ => Err(syn::Error::new(ident.span(), "Expected type.")),
+    }
+}
+
+/// Parse an `#[option(doc="...", default="...", value_type="...",
+/// example="...")]` attribute and return data in the form of an `OptionField`.
+fn handle_option(field: &Field, attr: &Attribute) -> syn::Result<proc_macro2::TokenStream> {
+    // unwrap is safe because we're only going over named fields
+    let ident = field.ident.as_ref().unwrap();
+
+    let FieldAttributes {
+        doc,
+        default,
+        value_type,
+        example,
+    } = attr.parse_args::<FieldAttributes>()?;
+    let kebab_name = LitStr::new(&ident.to_string().replace('_', "-"), ident.span());
+
+    Ok(quote_spanned!(
+        ident.span() => OptionEntry::Field(OptionField {
+            name: #kebab_name,
+            doc: &#doc,
+            default: &#default,
+            value_type: &#value_type,
+            example: &#example,
+        })
+    ))
+}
+
+#[derive(Debug)]
+struct FieldAttributes {
+    doc: String,
+    default: String,
+    value_type: String,
+    example: String,
+}
+
+impl Parse for FieldAttributes {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let doc = _parse_key_value(input, "doc")?;
+        input.parse::<Comma>()?;
+        let default = _parse_key_value(input, "default")?;
+        input.parse::<Comma>()?;
+        let value_type = _parse_key_value(input, "value_type")?;
+        input.parse::<Comma>()?;
+        let example = _parse_key_value(input, "example")?;
+        if !input.is_empty() {
+            input.parse::<Comma>()?;
+        }
+
+        Ok(FieldAttributes {
+            doc: textwrap::dedent(&doc).trim_matches('\n').to_string(),
+            default,
+            value_type,
+            example: textwrap::dedent(&example).trim_matches('\n').to_string(),
+        })
+    }
+}
+
+fn _parse_key_value(input: ParseStream, name: &str) -> syn::Result<String> {
+    let ident: proc_macro2::Ident = input.parse()?;
+    if ident != name {
+        return Err(syn::Error::new(
+            ident.span(),
+            format!("Expected `{name}` name"),
+        ));
+    }
+
+    input.parse::<Token![=]>()?;
+    let value: Lit = input.parse()?;
+
+    match &value {
+        Lit::Str(v) => Ok(v.value()),
+        _ => Err(syn::Error::new(value.span(), "Expected literal string")),
+    }
+}

src/ast/branch_detection.rs

@@ -0,0 +1,105 @@
+use std::cmp::Ordering;
+
+use rustc_hash::FxHashMap;
+use rustpython_ast::ExcepthandlerKind::ExceptHandler;
+use rustpython_ast::Stmt;
+use rustpython_parser::ast::StmtKind;
+
+use crate::ast::types::RefEquality;
+
+/// Return the common ancestor of `left` and `right` below `stop`, or `None`.
+fn common_ancestor<'a>(
+    left: &'a RefEquality<'a, Stmt>,
+    right: &'a RefEquality<'a, Stmt>,
+    stop: Option<&'a RefEquality<'a, Stmt>>,
+    depths: &'a FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &'a FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> Option<&'a RefEquality<'a, Stmt>> {
+    if let Some(stop) = stop {
+        if left == stop || right == stop {
+            return None;
+        }
+    }
+    if left == right {
+        return Some(left);
+    }
+
+    let left_depth = depths.get(left)?;
+    let right_depth = depths.get(right)?;
+    match left_depth.cmp(right_depth) {
+        Ordering::Less => common_ancestor(
+            left,
+            child_to_parent.get(right)?,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+        Ordering::Equal => common_ancestor(
+            child_to_parent.get(left)?,
+            child_to_parent.get(right)?,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+        Ordering::Greater => common_ancestor(
+            child_to_parent.get(left)?,
+            right,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+    }
+}
+
+/// Return the alternative branches for a given node.
+fn alternatives<'a>(node: &'a RefEquality<'a, Stmt>) -> Vec<Vec<RefEquality<'a, Stmt>>> {
+    match &node.0.node {
+        StmtKind::If { body, .. } => vec![body.iter().map(RefEquality).collect()],
+        StmtKind::Try {
+            body,
+            handlers,
+            orelse,
+            ..
+        } => vec![body.iter().chain(orelse.iter()).map(RefEquality).collect()]
+            .into_iter()
+            .chain(handlers.iter().map(|handler| {
+                let ExceptHandler { body, .. } = &handler.node;
+                body.iter().map(RefEquality).collect()
+            }))
+            .collect(),
+        _ => vec![],
+    }
+}
+
+/// Return `true` if `node` is a descendent of any of the nodes in `ancestors`.
+fn descendant_of<'a>(
+    node: &RefEquality<'a, Stmt>,
+    ancestors: &[RefEquality<'a, Stmt>],
+    stop: &RefEquality<'a, Stmt>,
+    depths: &FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> bool {
+    ancestors.iter().any(|ancestor| {
+        common_ancestor(node, ancestor, Some(stop), depths, child_to_parent).is_some()
+    })
+}
+
+/// Return `true` if `left` and `right` are on different branches of an `if` or
+/// `try` statement.
+pub fn different_forks<'a>(
+    left: &RefEquality<'a, Stmt>,
+    right: &RefEquality<'a, Stmt>,
+    depths: &FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> bool {
+    if let Some(ancestor) = common_ancestor(left, right, None, depths, child_to_parent) {
+        for items in alternatives(ancestor) {
+            let l = descendant_of(left, &items, ancestor, depths, child_to_parent);
+            let r = descendant_of(right, &items, ancestor, depths, child_to_parent);
+            if l ^ r {
+                return true;
+            }
+        }
+    }
+    false
+}

src/ast/cast.rs

@@ -0,0 +1,9 @@
+use rustpython_ast::{Expr, Stmt, StmtKind};
+
+pub fn decorator_list(stmt: &Stmt) -> &Vec<Expr> {
+    match &stmt.node {
+        StmtKind::FunctionDef { decorator_list, .. }
+        | StmtKind::AsyncFunctionDef { decorator_list, .. } => decorator_list,
+        _ => panic!("Expected StmtKind::FunctionDef | StmtKind::AsyncFunctionDef"),
+    }
+}

src/ast/function_type.rs

@@ -0,0 +1,65 @@
+use rustc_hash::{FxHashMap, FxHashSet};
+use rustpython_ast::Expr;
+
+use crate::ast::helpers::{
+    collect_call_paths, dealias_call_path, match_call_path, to_module_and_member,
+};
+use crate::ast::types::{Scope, ScopeKind};
+
+const CLASS_METHODS: [&str; 3] = ["__new__", "__init_subclass__", "__class_getitem__"];
+const METACLASS_BASES: [(&str, &str); 2] = [("", "type"), ("abc", "ABCMeta")];
+
+pub enum FunctionType {
+    Function,
+    Method,
+    ClassMethod,
+    StaticMethod,
+}
+
+/// Classify a function based on its scope, name, and decorators.
+pub fn classify(
+    scope: &Scope,
+    name: &str,
+    decorator_list: &[Expr],
+    from_imports: &FxHashMap<&str, FxHashSet<&str>>,
+    import_aliases: &FxHashMap<&str, &str>,
+    classmethod_decorators: &[String],
+    staticmethod_decorators: &[String],
+) -> FunctionType {
+    let ScopeKind::Class(scope) = &scope.kind else {
+        return FunctionType::Function;
+    };
+    // Special-case class method, like `__new__`.
+    if CLASS_METHODS.contains(&name)
+        || scope.bases.iter().any(|expr| {
+            // The class itself extends a known metaclass, so all methods are class methods.
+            let call_path = dealias_call_path(collect_call_paths(expr), import_aliases);
+            METACLASS_BASES
+                .iter()
+                .any(|(module, member)| match_call_path(&call_path, module, member, from_imports))
+        })
+        || decorator_list.iter().any(|expr| {
+            // The method is decorated with a class method decorator (like `@classmethod`).
+            let call_path = dealias_call_path(collect_call_paths(expr), import_aliases);
+            classmethod_decorators.iter().any(|decorator| {
+                let (module, member) = to_module_and_member(decorator);
+                match_call_path(&call_path, module, member, from_imports)
+            })
+        })
+    {
+        FunctionType::ClassMethod
+    } else if decorator_list.iter().any(|expr| {
+        // The method is decorated with a static method decorator (like
+        // `@staticmethod`).
+        let call_path = dealias_call_path(collect_call_paths(expr), import_aliases);
+        staticmethod_decorators.iter().any(|decorator| {
+            let (module, member) = to_module_and_member(decorator);
+            match_call_path(&call_path, module, member, from_imports)
+        })
+    }) {
+        FunctionType::StaticMethod
+    } else {
+        // It's an instance method.
+        FunctionType::Method
+    }
+}

src/ast/mod.rs

@@ -1,3 +1,6 @@
+pub mod branch_detection;
+pub mod cast;
+pub mod function_type;
 pub mod helpers;
 pub mod operations;
 pub mod relocate;

src/ast/operations.rs

@@ -1,12 +1,15 @@
+use rustc_hash::FxHashMap;
 use rustpython_ast::{Cmpop, Located};
 use rustpython_parser::ast::{Constant, Expr, ExprKind, Stmt, StmtKind};
 use rustpython_parser::lexer;
 use rustpython_parser::lexer::Tok;
 
-use crate::ast::types::{BindingKind, Scope};
+use crate::ast::types::{Binding, BindingKind, Scope};
+use crate::ast::visitor;
+use crate::ast::visitor::Visitor;
 
 /// Extract the names bound to a given __all__ assignment.
-pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
+pub fn extract_all_names(stmt: &Stmt, scope: &Scope, bindings: &[Binding]) -> Vec<String> {
     fn add_to_names(names: &mut Vec<String>, elts: &[Expr]) {
         for elt in elts {
             if let ExprKind::Constant {
@@ -23,8 +26,8 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
 
     // Grab the existing bound __all__ values.
     if let StmtKind::AugAssign { .. } = &stmt.node {
-        if let Some(binding) = scope.values.get("__all__") {
-            if let BindingKind::Export(existing) = &binding.kind {
+        if let Some(index) = scope.values.get("__all__") {
+            if let BindingKind::Export(existing) = &bindings[*index].kind {
                 names.extend_from_slice(existing);
             }
         }
@@ -69,6 +72,38 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
     names
 }
 
+#[derive(Default)]
+struct GlobalVisitor<'a> {
+    globals: FxHashMap<&'a str, &'a Stmt>,
+}
+
+impl<'a> Visitor<'a> for GlobalVisitor<'a> {
+    fn visit_stmt(&mut self, stmt: &'a Stmt) {
+        match &stmt.node {
+            StmtKind::Global { names } => {
+                for name in names {
+                    self.globals.insert(name, stmt);
+                }
+            }
+            StmtKind::FunctionDef { .. }
+            | StmtKind::AsyncFunctionDef { .. }
+            | StmtKind::ClassDef { .. } => {
+                // Don't recurse.
+            }
+            _ => visitor::walk_stmt(self, stmt),
+        }
+    }
+}
+
+/// Extract a map from global name to its last-defining `Stmt`.
+pub fn extract_globals(body: &[Stmt]) -> FxHashMap<&str, &Stmt> {
+    let mut visitor = GlobalVisitor::default();
+    for stmt in body {
+        visitor.visit_stmt(stmt);
+    }
+    visitor.globals
+}
+
 /// Check if a node is parent of a conditional branch.
 pub fn on_conditional_branch<'a>(parents: &mut impl Iterator<Item = &'a Stmt>) -> bool {
     parents.any(|parent| {
@@ -94,23 +129,132 @@ pub fn in_nested_block<'a>(parents: &mut impl Iterator<Item = &'a Stmt>) -> bool
     })
 }
 
-/// Check if a node represents an unpacking assignment.
-pub fn is_unpacking_assignment(stmt: &Stmt) -> bool {
-    let StmtKind::Assign { targets, value, .. } = &stmt.node else {
-        return false;
-    };
-    if !targets.iter().any(|child| {
-        matches!(
-            child.node,
-            ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
-        )
-    }) {
-        return false;
+/// Returns `true` if `parent` contains `child`.
+fn contains(parent: &Expr, child: &Expr) -> bool {
+    match &parent.node {
+        ExprKind::BoolOp { values, .. } => values.iter().any(|parent| contains(parent, child)),
+        ExprKind::NamedExpr { target, value } => contains(target, child) || contains(value, child),
+        ExprKind::BinOp { left, right, .. } => contains(left, child) || contains(right, child),
+        ExprKind::UnaryOp { operand, .. } => contains(operand, child),
+        ExprKind::Lambda { body, .. } => contains(body, child),
+        ExprKind::IfExp { test, body, orelse } => {
+            contains(test, child) || contains(body, child) || contains(orelse, child)
+        }
+        ExprKind::Dict { keys, values } => keys
+            .iter()
+            .chain(values.iter())
+            .any(|parent| contains(parent, child)),
+        ExprKind::Set { elts } => elts.iter().any(|parent| contains(parent, child)),
+        ExprKind::ListComp { elt, .. } => contains(elt, child),
+        ExprKind::SetComp { elt, .. } => contains(elt, child),
+        ExprKind::DictComp { key, value, .. } => contains(key, child) || contains(value, child),
+        ExprKind::GeneratorExp { elt, .. } => contains(elt, child),
+        ExprKind::Await { value } => contains(value, child),
+        ExprKind::Yield { value } => value.as_ref().map_or(false, |value| contains(value, child)),
+        ExprKind::YieldFrom { value } => contains(value, child),
+        ExprKind::Compare {
+            left, comparators, ..
+        } => contains(left, child) || comparators.iter().any(|parent| contains(parent, child)),
+        ExprKind::Call {
+            func,
+            args,
+            keywords,
+        } => {
+            contains(func, child)
+                || args.iter().any(|parent| contains(parent, child))
+                || keywords
+                    .iter()
+                    .any(|keyword| contains(&keyword.node.value, child))
+        }
+        ExprKind::FormattedValue {
+            value, format_spec, ..
+        } => {
+            contains(value, child)
+                || format_spec
+                    .as_ref()
+                    .map_or(false, |value| contains(value, child))
+        }
+        ExprKind::JoinedStr { values } => values.iter().any(|parent| contains(parent, child)),
+        ExprKind::Constant { .. } => false,
+        ExprKind::Attribute { value, .. } => contains(value, child),
+        ExprKind::Subscript { value, slice, .. } => {
+            contains(value, child) || contains(slice, child)
+        }
+        ExprKind::Starred { value, .. } => contains(value, child),
+        ExprKind::Name { .. } => parent == child,
+        ExprKind::List { elts, .. } => elts.iter().any(|parent| contains(parent, child)),
+        ExprKind::Tuple { elts, .. } => elts.iter().any(|parent| contains(parent, child)),
+        ExprKind::Slice { lower, upper, step } => {
+            lower.as_ref().map_or(false, |value| contains(value, child))
+                || upper.as_ref().map_or(false, |value| contains(value, child))
+                || step.as_ref().map_or(false, |value| contains(value, child))
+        }
+    }
+}
+
+/// Check if a node represents an unpacking assignment.
+pub fn is_unpacking_assignment(parent: &Stmt, child: &Expr) -> bool {
+    match &parent.node {
+        StmtKind::With { items, .. } => items.iter().any(|item| {
+            if let Some(optional_vars) = &item.optional_vars {
+                if matches!(optional_vars.node, ExprKind::Tuple { .. }) {
+                    if contains(optional_vars, child) {
+                        return true;
+                    }
+                }
+            }
+            false
+        }),
+        StmtKind::Assign { targets, value, .. } => {
+            // In `(a, b) = (1, 2)`, `(1, 2)` is the target, and it is a tuple.
+            let value_is_tuple = matches!(
+                &value.node,
+                ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
+            );
+            // In `(a, b) = coords = (1, 2)`, `(a, b)` and `coords` are the targets, and
+            // `(a, b`) is a tuple. (We use "tuple" as a placeholder for any
+            // unpackable expression.)
+            let targets_are_tuples = targets.iter().all(|item| {
+                matches!(
+                    item.node,
+                    ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
+                )
+            });
+            // If we're looking at `a` in `(a, b) = coords = (1, 2)`, then we should
+            // identify that the current expression is in a tuple.
+            let child_in_tuple = targets_are_tuples
+                || targets.iter().any(|item| {
+                    matches!(
+                        item.node,
+                        ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
+                    ) && contains(item, child)
+                });
+
+            // If our child is a tuple, and value is not, it's always an unpacking
+            // expression. Ex) `x, y = tup`
+            if child_in_tuple && !value_is_tuple {
+                return true;
+            }
+
+            // If our child isn't a tuple, but value is, it's never an unpacking expression.
+            // Ex) `coords = (1, 2)`
+            if !child_in_tuple && value_is_tuple {
+                return false;
+            }
+
+            // If our target and the value are both tuples, then it's an unpacking
+            // expression assuming there's at least one non-tuple child.
+            // Ex) Given `(x, y) = coords = 1, 2`, `(x, y)` is considered an unpacking
+            // expression. Ex) Given `(x, y) = (a, b) = 1, 2`, `(x, y)` isn't
+            // considered an unpacking expression.
+            if child_in_tuple && value_is_tuple {
+                return !targets_are_tuples;
+            }
+
+            false
+        }
+        _ => false,
     }
-    !matches!(
-        &value.node,
-        ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
-    )
 }
 
 pub type LocatedCmpop<U = ()> = Located<Cmpop, U>;

src/ast/types.rs

@@ -1,7 +1,7 @@
 use std::sync::atomic::{AtomicUsize, Ordering};
 
 use rustc_hash::FxHashMap;
-use rustpython_ast::{Expr, Keyword, Stmt};
+use rustpython_ast::{Arguments, Expr, Keyword, Stmt};
 use rustpython_parser::ast::{Located, Location};
 
 fn id() -> usize {
@@ -30,36 +30,60 @@ impl Range {
     }
 }
 
-#[derive(Clone, Debug)]
-pub struct FunctionScope {
+#[derive(Debug)]
+pub struct FunctionDef<'a> {
+    // Properties derived from StmtKind::FunctionDef.
+    pub name: &'a str,
+    pub args: &'a Arguments,
+    pub body: &'a [Stmt],
+    pub decorator_list: &'a [Expr],
+    // pub returns: Option<&'a Expr>,
+    // pub type_comment: Option<&'a str>,
+    // Scope-specific properties.
+    // TODO(charlie): Create AsyncFunctionDef to mirror the AST.
     pub async_: bool,
-    pub uses_locals: bool,
+    pub globals: FxHashMap<&'a str, &'a Stmt>,
 }
 
-#[derive(Clone, Debug)]
-pub struct ClassScope<'a> {
+#[derive(Debug)]
+pub struct ClassDef<'a> {
+    // Properties derived from StmtKind::ClassDef.
     pub name: &'a str,
     pub bases: &'a [Expr],
     pub keywords: &'a [Keyword],
+    // pub body: &'a [Stmt],
     pub decorator_list: &'a [Expr],
+    // Scope-specific properties.
+    pub globals: FxHashMap<&'a str, &'a Stmt>,
 }
 
-#[derive(Clone, Debug)]
+#[derive(Debug)]
+pub struct Lambda<'a> {
+    pub args: &'a Arguments,
+    pub body: &'a Expr,
+}
+
+#[derive(Debug)]
 pub enum ScopeKind<'a> {
-    Class(ClassScope<'a>),
-    Function(FunctionScope),
+    Class(ClassDef<'a>),
+    Function(FunctionDef<'a>),
     Generator,
     Module,
     Arg,
-    Lambda,
+    Lambda(Lambda<'a>),
 }
 
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct Scope<'a> {
     pub id: usize,
     pub kind: ScopeKind<'a>,
     pub import_starred: bool,
-    pub values: FxHashMap<&'a str, Binding>,
+    pub uses_locals: bool,
+    /// A map from bound name to binding index.
+    pub values: FxHashMap<&'a str, usize>,
+    /// A list of (name, index) pairs for bindings that were overridden in the
+    /// scope.
+    pub overridden: Vec<(&'a str, usize)>,
 }
 
 impl<'a> Scope<'a> {
@@ -68,43 +92,122 @@ impl<'a> Scope<'a> {
             id: id(),
             kind,
             import_starred: false,
+            uses_locals: false,
             values: FxHashMap::default(),
+            overridden: Vec::new(),
         }
     }
 }
 
-#[derive(Clone, Debug)]
-pub struct BindingContext {
-    pub defined_by: usize,
-    pub defined_in: Option<usize>,
-}
-
 #[derive(Clone, Debug)]
 pub enum BindingKind {
     Annotation,
     Argument,
     Assignment,
-    // TODO(charlie): This seems to be a catch-all.
     Binding,
     LoopVar,
     Global,
     Nonlocal,
     Builtin,
     ClassDefinition,
-    Definition,
+    FunctionDefinition,
     Export(Vec<String>),
     FutureImportation,
     StarImportation(Option<usize>, Option<String>),
-    Importation(String, String, BindingContext),
-    FromImportation(String, String, BindingContext),
-    SubmoduleImportation(String, String, BindingContext),
+    Importation(String, String),
+    FromImportation(String, String),
+    SubmoduleImportation(String, String),
 }
 
 #[derive(Clone, Debug)]
-pub struct Binding {
+pub struct Binding<'a> {
     pub kind: BindingKind,
     pub range: Range,
+    /// The statement in which the `Binding` was defined.
+    pub source: Option<RefEquality<'a, Stmt>>,
     /// Tuple of (scope index, range) indicating the scope and range at which
     /// the binding was last used.
     pub used: Option<(usize, Range)>,
 }
+
+// Pyflakes defines the following binding hierarchy (via inheritance):
+//   Binding
+//    ExportBinding
+//    Annotation
+//    Argument
+//    Assignment
+//      NamedExprAssignment
+//    Definition
+//      FunctionDefinition
+//      ClassDefinition
+//      Builtin
+//      Importation
+//        SubmoduleImportation
+//        ImportationFrom
+//        StarImportation
+//        FutureImportation
+
+impl<'a> Binding<'a> {
+    pub fn is_definition(&self) -> bool {
+        matches!(
+            self.kind,
+            BindingKind::ClassDefinition
+                | BindingKind::FunctionDefinition
+                | BindingKind::Builtin
+                | BindingKind::FutureImportation
+                | BindingKind::StarImportation(..)
+                | BindingKind::Importation(..)
+                | BindingKind::FromImportation(..)
+                | BindingKind::SubmoduleImportation(..)
+        )
+    }
+
+    pub fn redefines(&self, existing: &'a Binding) -> bool {
+        match &self.kind {
+            BindingKind::Importation(_, full_name) | BindingKind::FromImportation(_, full_name) => {
+                if let BindingKind::SubmoduleImportation(_, existing_full_name) = &existing.kind {
+                    return full_name == existing_full_name;
+                }
+            }
+            BindingKind::SubmoduleImportation(_, full_name) => {
+                if let BindingKind::Importation(_, existing_full_name)
+                | BindingKind::FromImportation(_, existing_full_name)
+                | BindingKind::SubmoduleImportation(_, existing_full_name) = &existing.kind
+                {
+                    return full_name == existing_full_name;
+                }
+            }
+            BindingKind::Annotation => {
+                return false;
+            }
+            BindingKind::FutureImportation => {
+                return false;
+            }
+            BindingKind::StarImportation(..) => {
+                return false;
+            }
+            _ => {}
+        }
+        existing.is_definition()
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub struct RefEquality<'a, T>(pub &'a T);
+
+impl<'a, T> std::hash::Hash for RefEquality<'a, T> {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: std::hash::Hasher,
+    {
+        (self.0 as *const T).hash(state);
+    }
+}
+
+impl<'a, 'b, T> PartialEq<RefEquality<'b, T>> for RefEquality<'a, T> {
+    fn eq(&self, other: &RefEquality<'b, T>) -> bool {
+        std::ptr::eq(self.0, other.0)
+    }
+}
+
+impl<'a, T> Eq for RefEquality<'a, T> {}

src/ast/visitor.rs

@@ -159,8 +159,8 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
             orelse,
             ..
         } => {
-            visitor.visit_expr(target);
             visitor.visit_expr(iter);
+            visitor.visit_expr(target);
             for stmt in body {
                 visitor.visit_stmt(stmt);
             }
@@ -175,8 +175,8 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
             orelse,
             ..
         } => {
-            visitor.visit_expr(target);
             visitor.visit_expr(iter);
+            visitor.visit_expr(target);
             for stmt in body {
                 visitor.visit_stmt(stmt);
             }

src/ast/whitespace.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::str::Lines;
 
 use rustpython_ast::{Located, Location};
@@ -5,31 +6,26 @@ use rustpython_ast::{Located, Location};
 use crate::ast::types::Range;
 use crate::check_ast::Checker;
 
+/// Extract the leading indentation from a line.
+pub fn indentation<'a, T>(checker: &'a Checker, located: &'a Located<T>) -> Cow<'a, str> {
+    let range = Range::from_located(located);
+    checker.locator.slice_source_code_range(&Range {
+        location: Location::new(range.location.row(), 0),
+        end_location: Location::new(range.location.row(), range.location.column()),
+    })
+}
+
 /// Extract the leading words from a line of text.
-pub fn leading_words(line: &str) -> String {
-    line.trim()
-        .chars()
-        .take_while(|char| char.is_alphanumeric() || char.is_whitespace())
-        .collect()
+pub fn leading_words(line: &str) -> &str {
+    let line = line.trim();
+    line.find(|char: char| !char.is_alphanumeric() && !char.is_whitespace())
+        .map_or(line, |index| &line[..index])
 }
 
 /// Extract the leading whitespace from a line of text.
-pub fn leading_space(line: &str) -> String {
-    line.chars()
-        .take_while(|char| char.is_whitespace())
-        .collect()
-}
-
-/// Extract the leading indentation from a line.
-pub fn indentation<T>(checker: &Checker, located: &Located<T>) -> String {
-    let range = Range::from_located(located);
-    checker
-        .locator
-        .slice_source_code_range(&Range {
-            location: Location::new(range.location.row(), 0),
-            end_location: Location::new(range.location.row(), range.location.column()),
-        })
-        .to_string()
+pub fn leading_space(line: &str) -> &str {
+    line.find(|char: char| !char.is_whitespace())
+        .map_or(line, |index| &line[..index])
 }
 
 /// Replace any non-whitespace characters from an indentation string.

src/autofix/fixer.rs

@@ -10,7 +10,7 @@ use crate::autofix::Fix;
 use crate::checks::Check;
 use crate::source_code_locator::SourceCodeLocator;
 
-#[derive(Hash)]
+#[derive(Debug, Hash)]
 pub enum Mode {
     Generate,
     Apply,