Bump version to 0.0.45

Cargo.lock

@@ -1801,7 +1801,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.44"
+version = "0.0.45"
 dependencies = [
  "anyhow",
  "bincode",
@@ -1846,7 +1846,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
  "num-bigint",
  "rustpython-compiler-core",
@@ -1855,7 +1855,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
  "bincode",
  "bitflags",
@@ -1872,7 +1872,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
  "ahash",
  "anyhow",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.44"
+version = "0.0.45"
 edition = "2021"
 
 [lib]
@@ -18,15 +18,15 @@ common-path = { version = "1.0.0" }
 dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
-glob = "0.3.0"
-itertools = "0.10.3"
+glob = { version = "0.3.0" }
+itertools = { version = "0.10.3" }
 log = { version = "0.4.17" }
 notify = { version = "4.0.17" }
 once_cell = { version = "1.13.1" }
 path-absolutize = { version = "3.0.13", features = ["once_cell_cache"] }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "7d21c6923a506e79cc041708d83cef925efd33f4" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "966a80597d626a9a47eaec78471164422d341453" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 toml = { version = "0.5.9" }

README.md

@@ -86,7 +86,7 @@ ruff path/to/code/ --select F401 F403
 See `ruff --help` for more:
 
 ```shell
-ruff (v0.0.44)
+ruff (v0.0.45) 0.0.45
 An extremely fast Python linter.
 
 USAGE:
@@ -96,12 +96,20 @@ ARGS:
     <FILES>...
 
 OPTIONS:
-    -e, --exit-zero
-            Exit with status code "0", even upon detecting errors
+        --select <SELECT>...
+            List of error codes to enable
+        --extend-select <EXTEND_SELECT>...
+            Like --select, but adds additional error codes on top of the selected ones
+        --ignore <IGNORE>...
+            List of error codes to ignore
+        --extend-ignore <EXTEND_IGNORE>...
+            Like --ignore, but adds additional error codes on top of the ignored ones
         --exclude <EXCLUDE>...
             List of paths, used to exclude files and/or directories from checks
         --extend-exclude <EXTEND_EXCLUDE>...
             Like --exclude, but adds additional files and directories on top of the excluded ones
+    -e, --exit-zero
+            Exit with status code "0", even upon detecting errors
     -f, --fix
             Attempt to automatically fix lint errors
         --format <FORMAT>
@@ -109,14 +117,16 @@ OPTIONS:
             json]
     -h, --help
             Print help information
-        --ignore <IGNORE>...
-            List of error codes to ignore
     -n, --no-cache
             Disable cache reads
     -q, --quiet
             Disable all logging (but still exit with status code "1" upon detecting errors)
-        --select <SELECT>...
-            List of error codes to enable
+        --add-noqa
+            Enable automatic additions of noqa directives to failing lines
+        --show-files
+            See the files ruff will be run against with the current settings
+        --show-settings
+            See ruff's settings
     -v, --verbose
             Enable verbose logging
     -V, --version
@@ -125,6 +135,8 @@ OPTIONS:
             Run in watch mode by re-running whenever files change
 ```
 
+### Excluding files
+
 Exclusions are based on globs, and can be either:
 
 - Single-path patterns, like `.mypy_cache` (to exclude any directory named `.mypy_cache` in the
@@ -134,6 +146,50 @@ Exclusions are based on globs, and can be either:
   (to exclude any Python files in `directory`). Note that these paths are relative to the
   project root (e.g., the directory containing your `pyproject.toml`).
 
+### Ignoring errors
+
+To omit a lint check entirely, add it to the "ignore" list via `--ignore` or `--extend-ignore`,
+either  on the command-line or in your `project.toml` file.
+
+To ignore an error in-line, ruff uses a `noqa` system similar to [Flake8](https://flake8.pycqa.org/en/3.1.1/user/ignoring-errors.html).
+To ignore an individual error, add `# noqa: {code}` to the end of the line, like so:
+
+```python
+# Ignore F841.
+x = 1  # noqa: F841
+
+# Ignore E741 and F841.
+i = 1  # noqa: E741, F841
+
+# Ignore _all_ errors.
+x = 1  # noqa
+```
+
+Note that, for multi-line strings, the `noqa` directive should come at the end of the string, and
+will apply to the entire body, like so:
+
+```python
+"""Lorem ipsum dolor sit amet.
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+```
+
+ruff supports several (experimental) workflows to aid in `noqa` management.
+
+First, ruff provides a special error code, `M001`, to enforce that your `noqa` directives are
+"valid", in that the errors they _say_ they ignore are actually being triggered on that line (and
+thus suppressed). **You can run `ruff /path/to/file.py --extend-select M001` to flag unused `noqa`
+directives.**
+
+Second, ruff can _automatically remove_ unused `noqa` directives via its autofix functionality.
+**You can run `ruff /path/to/file.py --extend-select M001 --fix` to automatically remove unused
+`noqa` directives.**
+
+Third, ruff can _automatically add_ `noqa` directives to all failing lines. This is useful when
+migrating a new codebase to ruff. **You can run `ruff /path/to/file.py --add-noqa` to automatically
+add `noqa` directives to all failing lines, with the appropriate error codes.**
+
 ### Compatibility with Black
 
 ruff is compatible with [Black](https://github.com/psf/black) out-of-the-box, as long as
@@ -205,6 +261,7 @@ Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis F
 | F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` |
 | R001 | UselessObjectInheritance | Class `...` inherits from object |
 | R002 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |
+| M001 | UnusedNOQA | Unused `noqa` directive |
 
 ## Development
 

resources/test/fixtures/E501.py

@@ -5,5 +5,12 @@
 Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
 """
 
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+
 _ = "---------------------------------------------------------------------------AAAAAAA"
 _ = "---------------------------------------------------------------------------亜亜亜亜亜亜亜"

resources/test/fixtures/M001.py

@@ -0,0 +1,57 @@
+def f() -> None:
+    # Valid
+    a = 1  # noqa
+
+    # Valid
+    b = 2  # noqa: F841
+
+    # Invalid
+    c = 1  # noqa
+    print(c)
+
+    # Invalid
+    d = 1  # noqa: E501
+
+    # Invalid
+    d = 1  # noqa: F841, E501
+
+
+# Valid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+
+# Valid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501, F841
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.
+"""  # noqa: E501
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.
+"""  # noqa

src/check_lines.rs

@@ -1,6 +1,11 @@
+use std::collections::BTreeMap;
+
 use rustpython_parser::ast::Location;
 
-use crate::checks::{Check, CheckCode, CheckKind};
+use crate::autofix::fixer;
+use crate::checks::{Check, CheckCode, CheckKind, Fix};
+use crate::noqa;
+use crate::noqa::Directive;
 use crate::settings::Settings;
 
 /// Whether the given line is too long and should be reported.
@@ -19,17 +24,58 @@ fn should_enforce_line_length(line: &str, length: usize, limit: usize) -> bool {
     }
 }
 
-pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings) {
+pub fn check_lines(
+    checks: &mut Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+    settings: &Settings,
+    autofix: &fixer::Mode,
+) {
     let enforce_line_too_long = settings.select.contains(&CheckCode::E501);
+    let enforce_noqa = settings.select.contains(&CheckCode::M001);
+
+    let mut noqa_directives: BTreeMap<usize, (Directive, Vec<&str>)> = BTreeMap::new();
 
     let mut line_checks = vec![];
     let mut ignored = vec![];
-    for (row, line) in contents.lines().enumerate() {
+
+    let lines: Vec<&str> = contents.lines().collect();
+    for (lineno, line) in lines.iter().enumerate() {
+        // Grab the noqa (logical) line number for the current (physical) line.
+        // If there are newlines at the end of the file, they won't be represented in
+        // `noqa_line_for`, so fallback to the current line.
+        let noqa_lineno = noqa_line_for
+            .get(lineno)
+            .map(|lineno| lineno - 1)
+            .unwrap_or(lineno);
+
+        if enforce_noqa {
+            noqa_directives
+                .entry(noqa_lineno)
+                .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+        }
+
         // Remove any ignored checks.
         // TODO(charlie): Only validate checks for the current line.
         for (index, check) in checks.iter().enumerate() {
-            if check.location.row() == row + 1 && check.is_inline_ignored(line) {
-                ignored.push(index);
+            if check.location.row() == lineno + 1 {
+                let noqa = noqa_directives
+                    .entry(noqa_lineno)
+                    .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+
+                match noqa {
+                    (Directive::All(_), matches) => {
+                        matches.push(check.kind.code().as_str());
+                        ignored.push(index)
+                    }
+                    (Directive::Codes(_, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_str()) {
+                            matches.push(check.kind.code().as_str());
+                            ignored.push(index);
+                        }
+                    }
+                    (Directive::None, _) => {}
+                }
             }
         }
 
@@ -37,16 +83,94 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)
         if enforce_line_too_long {
             let line_length = line.chars().count();
             if should_enforce_line_length(line, line_length, settings.line_length) {
+                let noqa = noqa_directives
+                    .entry(noqa_lineno)
+                    .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+
                 let check = Check::new(
                     CheckKind::LineTooLong(line_length, settings.line_length),
-                    Location::new(row + 1, settings.line_length + 1),
+                    Location::new(lineno + 1, settings.line_length + 1),
                 );
-                if !check.is_inline_ignored(line) {
-                    line_checks.push(check);
+
+                match noqa {
+                    (Directive::All(_), matches) => {
+                        matches.push(check.kind.code().as_str());
+                    }
+                    (Directive::Codes(_, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_str()) {
+                            matches.push(check.kind.code().as_str());
+                        } else {
+                            line_checks.push(check);
+                        }
+                    }
+                    (Directive::None, _) => line_checks.push(check),
                 }
             }
         }
     }
+
+    // Enforce that the noqa directive was actually used.
+    if enforce_noqa {
+        for (row, (directive, matches)) in noqa_directives {
+            match directive {
+                Directive::All(column) => {
+                    if matches.is_empty() {
+                        let mut check = Check::new(
+                            CheckKind::UnusedNOQA(None),
+                            Location::new(row + 1, column + 1),
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            check.amend(Fix {
+                                content: "".to_string(),
+                                start: Location::new(row + 1, column + 1),
+                                end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                applied: false,
+                            });
+                        }
+                        line_checks.push(check);
+                    }
+                }
+                Directive::Codes(column, codes) => {
+                    let mut invalid_codes = vec![];
+                    let mut valid_codes = vec![];
+                    for code in codes {
+                        if !matches.contains(&code) {
+                            invalid_codes.push(code);
+                        } else {
+                            valid_codes.push(code);
+                        }
+                    }
+
+                    if !invalid_codes.is_empty() {
+                        let mut check = Check::new(
+                            CheckKind::UnusedNOQA(Some(invalid_codes.join(", "))),
+                            Location::new(row + 1, column + 1),
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            if valid_codes.is_empty() {
+                                check.amend(Fix {
+                                    content: "".to_string(),
+                                    start: Location::new(row + 1, column + 1),
+                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    applied: false,
+                                });
+                            } else {
+                                check.amend(Fix {
+                                    content: format!("  # noqa: {}", valid_codes.join(", ")),
+                                    start: Location::new(row + 1, column + 1),
+                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    applied: false,
+                                });
+                            }
+                        }
+                        line_checks.push(check);
+                    }
+                }
+                Directive::None => {}
+            }
+        }
+    }
+
     ignored.sort();
     for index in ignored.iter().rev() {
         checks.swap_remove(*index);
@@ -64,15 +188,24 @@ mod tests {
     #[test]
     fn e501_non_ascii_char() {
         let line = "'\u{4e9c}' * 2"; // 7 in UTF-32, 9 in UTF-8.
+        let noqa_line_for: Vec<usize> = vec![1];
         let check_with_max_line_length = |line_length: usize| {
             let mut checks: Vec<Check> = vec![];
             let settings = Settings {
+                pyproject: None,
+                project_root: None,
                 line_length,
                 exclude: vec![],
                 extend_exclude: vec![],
                 select: BTreeSet::from_iter(vec![CheckCode::E501]),
             };
-            check_lines(&mut checks, line, &settings);
+            check_lines(
+                &mut checks,
+                line,
+                &noqa_line_for,
+                &settings,
+                &fixer::Mode::Generate,
+            );
             return checks;
         };
         assert!(!check_with_max_line_length(6).is_empty());

src/checks.rs

@@ -1,12 +1,10 @@
 use std::str::FromStr;
 
 use anyhow::Result;
-use once_cell::sync::Lazy;
-use regex::Regex;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
-pub const ALL_CHECK_CODES: [CheckCode; 44] = [
+pub const DEFAULT_CHECK_CODES: [CheckCode; 42] = [
     CheckCode::E402,
     CheckCode::E501,
     CheckCode::E711,
@@ -49,6 +47,52 @@ pub const ALL_CHECK_CODES: [CheckCode; 44] = [
     CheckCode::F831,
     CheckCode::F841,
     CheckCode::F901,
+];
+
+pub const ALL_CHECK_CODES: [CheckCode; 45] = [
+    CheckCode::E402,
+    CheckCode::E501,
+    CheckCode::E711,
+    CheckCode::E712,
+    CheckCode::E713,
+    CheckCode::E714,
+    CheckCode::E721,
+    CheckCode::E722,
+    CheckCode::E731,
+    CheckCode::E741,
+    CheckCode::E742,
+    CheckCode::E743,
+    CheckCode::E902,
+    CheckCode::E999,
+    CheckCode::F401,
+    CheckCode::F402,
+    CheckCode::F403,
+    CheckCode::F404,
+    CheckCode::F405,
+    CheckCode::F406,
+    CheckCode::F407,
+    CheckCode::F541,
+    CheckCode::F601,
+    CheckCode::F602,
+    CheckCode::F621,
+    CheckCode::F622,
+    CheckCode::F631,
+    CheckCode::F632,
+    CheckCode::F633,
+    CheckCode::F634,
+    CheckCode::F701,
+    CheckCode::F702,
+    CheckCode::F704,
+    CheckCode::F706,
+    CheckCode::F707,
+    CheckCode::F722,
+    CheckCode::F821,
+    CheckCode::F822,
+    CheckCode::F823,
+    CheckCode::F831,
+    CheckCode::F841,
+    CheckCode::F901,
+    CheckCode::M001,
     CheckCode::R001,
     CheckCode::R002,
 ];
@@ -99,6 +143,7 @@ pub enum CheckCode {
     F901,
     R001,
     R002,
+    M001,
 }
 
 impl FromStr for CheckCode {
@@ -150,6 +195,7 @@ impl FromStr for CheckCode {
             "F901" => Ok(CheckCode::F901),
             "R001" => Ok(CheckCode::R001),
             "R002" => Ok(CheckCode::R002),
+            "M001" => Ok(CheckCode::M001),
             _ => Err(anyhow::anyhow!("Unknown check code: {s}")),
         }
     }
@@ -202,13 +248,14 @@ impl CheckCode {
             CheckCode::F901 => "F901",
             CheckCode::R001 => "R001",
             CheckCode::R002 => "R002",
+            CheckCode::M001 => "M001",
         }
     }
 
     /// The source for the check (either the AST, the filesystem, or the physical lines).
     pub fn lint_source(&self) -> &'static LintSource {
         match self {
-            CheckCode::E501 => &LintSource::Lines,
+            CheckCode::E501 | CheckCode::M001 => &LintSource::Lines,
             CheckCode::E902 | CheckCode::E999 => &LintSource::FileSystem,
             _ => &LintSource::AST,
         }
@@ -259,6 +306,7 @@ impl CheckCode {
             CheckCode::F831 => CheckKind::DuplicateArgumentName,
             CheckCode::F841 => CheckKind::UnusedVariable("...".to_string()),
             CheckCode::F901 => CheckKind::RaiseNotImplemented,
+            CheckCode::M001 => CheckKind::UnusedNOQA(None),
             CheckCode::R001 => CheckKind::UselessObjectInheritance("...".to_string()),
             CheckCode::R002 => CheckKind::NoAssertEquals,
         }
@@ -280,6 +328,7 @@ pub enum RejectedCmpop {
 
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
+    UnusedNOQA(Option<String>),
     AmbiguousClassName(String),
     AmbiguousFunctionName(String),
     AmbiguousVariableName(String),
@@ -376,6 +425,7 @@ impl CheckKind {
             CheckKind::UnusedVariable(_) => "UnusedVariable",
             CheckKind::UselessObjectInheritance(_) => "UselessObjectInheritance",
             CheckKind::YieldOutsideFunction => "YieldOutsideFunction",
+            CheckKind::UnusedNOQA(_) => "UnusedNOQA",
         }
     }
 
@@ -399,8 +449,8 @@ impl CheckKind {
             CheckKind::IfTuple => &CheckCode::F634,
             CheckKind::ImportShadowedByLoopVar(_, _) => &CheckCode::F402,
             CheckKind::ImportStarNotPermitted(_) => &CheckCode::F406,
-            CheckKind::ImportStarUsed(_) => &CheckCode::F403,
             CheckKind::ImportStarUsage(_, _) => &CheckCode::F405,
+            CheckKind::ImportStarUsed(_) => &CheckCode::F403,
             CheckKind::InvalidPrintSyntax => &CheckCode::F633,
             CheckKind::IsLiteral => &CheckCode::F632,
             CheckKind::LateFutureImport => &CheckCode::F404,
@@ -423,6 +473,7 @@ impl CheckKind {
             CheckKind::UndefinedLocal(_) => &CheckCode::F823,
             CheckKind::UndefinedName(_) => &CheckCode::F821,
             CheckKind::UnusedImport(_) => &CheckCode::F401,
+            CheckKind::UnusedNOQA(_) => &CheckCode::M001,
             CheckKind::UnusedVariable(_) => &CheckCode::F841,
             CheckKind::UselessObjectInheritance(_) => &CheckCode::R001,
             CheckKind::YieldOutsideFunction => &CheckCode::F704,
@@ -556,6 +607,10 @@ impl CheckKind {
             CheckKind::YieldOutsideFunction => {
                 "a `yield` or `yield from` statement outside of a function/method".to_string()
             }
+            CheckKind::UnusedNOQA(code) => match code {
+                None => "Unused `noqa` directive".to_string(),
+                Some(code) => format!("Unused `noqa` directive for: {code}"),
+            },
         }
     }
 
@@ -563,7 +618,9 @@ impl CheckKind {
     pub fn fixable(&self) -> bool {
         matches!(
             self,
-            CheckKind::NoAssertEquals | CheckKind::UselessObjectInheritance(_)
+            CheckKind::NoAssertEquals
+                | CheckKind::UselessObjectInheritance(_)
+                | CheckKind::UnusedNOQA(_)
         )
     }
 }
@@ -583,11 +640,6 @@ pub struct Check {
     pub fix: Option<Fix>,
 }
 
-static NO_QA_REGEX: Lazy<Regex> = Lazy::new(|| {
-    Regex::new(r"(?i)# noqa(?::\s?(?P<codes>([A-Z]+[0-9]+(?:[,\s]+)?)+))?").expect("Invalid regex")
-});
-static SPLIT_COMMA_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").expect("Invalid regex"));
-
 impl Check {
     pub fn new(kind: CheckKind, location: Location) -> Self {
         Self {
@@ -600,25 +652,4 @@ impl Check {
     pub fn amend(&mut self, fix: Fix) {
         self.fix = Some(fix);
     }
-
-    pub fn is_inline_ignored(&self, line: &str) -> bool {
-        match NO_QA_REGEX.captures(line) {
-            Some(caps) => match caps.name("codes") {
-                Some(codes) => {
-                    for code in SPLIT_COMMA_REGEX
-                        .split(codes.as_str())
-                        .map(|code| code.trim())
-                        .filter(|code| !code.is_empty())
-                    {
-                        if code == self.kind.code().as_str() {
-                            return true;
-                        }
-                    }
-                    false
-                }
-                None => true,
-            },
-            None => false,
-        }
-    }
 }

src/lib.rs

@@ -10,6 +10,7 @@ pub mod fs;
 pub mod linter;
 pub mod logging;
 pub mod message;
+mod noqa;
 pub mod printer;
 pub mod pyproject;
 mod python;

src/linter.rs

@@ -2,7 +2,8 @@ use std::path::Path;
 
 use anyhow::Result;
 use log::debug;
-use rustpython_parser::parser;
+use rustpython_parser::lexer::LexResult;
+use rustpython_parser::{lexer, parser};
 
 use crate::autofix::fixer;
 use crate::autofix::fixer::fix_file;
@@ -10,25 +11,30 @@ use crate::check_ast::check_ast;
 use crate::check_lines::check_lines;
 use crate::checks::{Check, CheckCode, CheckKind, LintSource};
 use crate::message::Message;
+use crate::noqa::add_noqa;
 use crate::settings::Settings;
-use crate::{cache, fs};
+use crate::{cache, fs, noqa};
 
 fn check_path(
     path: &Path,
     contents: &str,
+    tokens: Vec<LexResult>,
     settings: &Settings,
     autofix: &fixer::Mode,
 ) -> Vec<Check> {
     // Aggregate all checks.
     let mut checks: Vec<Check> = vec![];
 
+    // Determine the noqa line for every line in the source.
+    let noqa_line_for = noqa::extract_noqa_line_for(&tokens);
+
     // Run the AST-based checks.
     if settings
         .select
         .iter()
         .any(|check_code| matches!(check_code.lint_source(), LintSource::AST))
     {
-        match parser::parse_program(contents, "<filename>") {
+        match parser::parse_program_tokens(tokens, "<filename>") {
             Ok(python_ast) => {
                 checks.extend(check_ast(&python_ast, contents, settings, autofix, path))
             }
@@ -44,7 +50,7 @@ fn check_path(
     }
 
     // Run the lines-based checks.
-    check_lines(&mut checks, contents, settings);
+    check_lines(&mut checks, contents, &noqa_line_for, settings, autofix);
 
     checks
 }
@@ -66,8 +72,11 @@ pub fn lint_path(
     // Read the file from disk.
     let contents = fs::read_file(path)?;
 
+    // Tokenize once.
+    let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+
     // Generate checks.
-    let mut checks = check_path(path, &contents, settings, autofix);
+    let mut checks = check_path(path, &contents, tokens, settings, autofix);
 
     // Apply autofix.
     if matches!(autofix, fixer::Mode::Apply) {
@@ -89,12 +98,29 @@ pub fn lint_path(
     Ok(messages)
 }
 
+pub fn add_noqa_to_path(path: &Path, settings: &Settings) -> Result<usize> {
+    // Read the file from disk.
+    let contents = fs::read_file(path)?;
+
+    // Tokenize once.
+    let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+
+    // Determine the noqa line for every line in the source.
+    let noqa_line_for = noqa::extract_noqa_line_for(&tokens);
+
+    // Generate checks.
+    let checks = check_path(path, &contents, tokens, settings, &fixer::Mode::None);
+
+    add_noqa(&checks, &contents, &noqa_line_for, path)
+}
+
 #[cfg(test)]
 mod tests {
-    use std::collections::BTreeSet;
     use std::path::Path;
 
     use anyhow::Result;
+    use rustpython_parser::lexer;
+    use rustpython_parser::lexer::LexResult;
 
     use crate::autofix::fixer;
     use crate::checks::{Check, CheckCode};
@@ -108,19 +134,17 @@ mod tests {
         autofix: &fixer::Mode,
     ) -> Result<Vec<Check>> {
         let contents = fs::read_file(path)?;
-        Ok(linter::check_path(path, &contents, settings, autofix))
+        let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+        Ok(linter::check_path(
+            path, &contents, tokens, settings, autofix,
+        ))
     }
 
     #[test]
     fn e402() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E402.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E402]),
-            },
+            &settings::Settings::for_rule(CheckCode::E402),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -132,12 +156,7 @@ mod tests {
     fn e501() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E501.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E501]),
-            },
+            &settings::Settings::for_rule(CheckCode::E501),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -149,12 +168,7 @@ mod tests {
     fn e711() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E711.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E711]),
-            },
+            &settings::Settings::for_rule(CheckCode::E711),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -166,12 +180,7 @@ mod tests {
     fn e712() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E712.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E712]),
-            },
+            &settings::Settings::for_rule(CheckCode::E712),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -183,12 +192,7 @@ mod tests {
     fn e713() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E713.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E713]),
-            },
+            &settings::Settings::for_rule(CheckCode::E713),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -200,12 +204,7 @@ mod tests {
     fn e721() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E721.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E721]),
-            },
+            &settings::Settings::for_rule(CheckCode::E721),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -217,12 +216,7 @@ mod tests {
     fn e722() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E722.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E722]),
-            },
+            &settings::Settings::for_rule(CheckCode::E722),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -234,12 +228,7 @@ mod tests {
     fn e714() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E714.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E714]),
-            },
+            &settings::Settings::for_rule(CheckCode::E714),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -251,12 +240,7 @@ mod tests {
     fn e731() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E731.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E731]),
-            },
+            &settings::Settings::for_rule(CheckCode::E731),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -268,12 +252,7 @@ mod tests {
     fn e741() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E741.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E741]),
-            },
+            &settings::Settings::for_rule(CheckCode::E741),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -285,12 +264,7 @@ mod tests {
     fn e742() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E742.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E742]),
-            },
+            &settings::Settings::for_rule(CheckCode::E742),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -302,12 +276,7 @@ mod tests {
     fn e743() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/E743.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E743]),
-            },
+            &settings::Settings::for_rule(CheckCode::E743),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -319,12 +288,7 @@ mod tests {
     fn f401() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F401.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F401]),
-            },
+            &settings::Settings::for_rule(CheckCode::F401),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -336,12 +300,7 @@ mod tests {
     fn f402() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F402.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F402]),
-            },
+            &settings::Settings::for_rule(CheckCode::F402),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -353,12 +312,7 @@ mod tests {
     fn f403() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F403.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F403]),
-            },
+            &settings::Settings::for_rule(CheckCode::F403),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -370,12 +324,7 @@ mod tests {
     fn f404() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F404.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F404]),
-            },
+            &settings::Settings::for_rule(CheckCode::F404),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -387,12 +336,7 @@ mod tests {
     fn f405() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F405.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F405]),
-            },
+            &settings::Settings::for_rule(CheckCode::F405),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -404,12 +348,7 @@ mod tests {
     fn f406() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F406.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F406]),
-            },
+            &settings::Settings::for_rule(CheckCode::F406),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -421,12 +360,7 @@ mod tests {
     fn f407() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F407.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F407]),
-            },
+            &settings::Settings::for_rule(CheckCode::F407),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -438,12 +372,7 @@ mod tests {
     fn f541() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F541.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F541]),
-            },
+            &settings::Settings::for_rule(CheckCode::F541),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -455,12 +384,7 @@ mod tests {
     fn f601() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F601.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F601]),
-            },
+            &settings::Settings::for_rule(CheckCode::F601),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -472,12 +396,7 @@ mod tests {
     fn f602() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F602.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F602]),
-            },
+            &settings::Settings::for_rule(CheckCode::F602),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -489,12 +408,7 @@ mod tests {
     fn f622() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F622.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F622]),
-            },
+            &settings::Settings::for_rule(CheckCode::F622),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -506,12 +420,7 @@ mod tests {
     fn f631() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F631.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F631]),
-            },
+            &settings::Settings::for_rule(CheckCode::F631),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -523,12 +432,7 @@ mod tests {
     fn f632() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F632.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F632]),
-            },
+            &settings::Settings::for_rule(CheckCode::F632),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -540,12 +444,7 @@ mod tests {
     fn f633() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F633.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F633]),
-            },
+            &settings::Settings::for_rule(CheckCode::F633),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -557,12 +456,7 @@ mod tests {
     fn f634() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F634.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F634]),
-            },
+            &settings::Settings::for_rule(CheckCode::F634),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -574,12 +468,7 @@ mod tests {
     fn f701() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F701.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F701]),
-            },
+            &settings::Settings::for_rule(CheckCode::F701),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -591,12 +480,7 @@ mod tests {
     fn f702() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F702.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F702]),
-            },
+            &settings::Settings::for_rule(CheckCode::F702),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -608,12 +492,7 @@ mod tests {
     fn f704() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F704.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F704]),
-            },
+            &settings::Settings::for_rule(CheckCode::F704),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -625,12 +504,7 @@ mod tests {
     fn f706() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F706.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F706]),
-            },
+            &settings::Settings::for_rule(CheckCode::F706),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -642,12 +516,7 @@ mod tests {
     fn f707() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F707.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F707]),
-            },
+            &settings::Settings::for_rule(CheckCode::F707),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -659,12 +528,7 @@ mod tests {
     fn f722() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F722.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F722]),
-            },
+            &settings::Settings::for_rule(CheckCode::F722),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -676,12 +540,7 @@ mod tests {
     fn f821() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F821.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F821]),
-            },
+            &settings::Settings::for_rule(CheckCode::F821),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -693,12 +552,7 @@ mod tests {
     fn f822() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F822.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F822]),
-            },
+            &settings::Settings::for_rule(CheckCode::F822),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -710,12 +564,7 @@ mod tests {
     fn f823() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F823.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F823]),
-            },
+            &settings::Settings::for_rule(CheckCode::F823),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -727,12 +576,7 @@ mod tests {
     fn f831() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F831.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F831]),
-            },
+            &settings::Settings::for_rule(CheckCode::F831),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -744,12 +588,7 @@ mod tests {
     fn f841() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F841.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F841]),
-            },
+            &settings::Settings::for_rule(CheckCode::F841),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -761,12 +600,19 @@ mod tests {
     fn f901() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/F901.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F901]),
-            },
+            &settings::Settings::for_rule(CheckCode::F901),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn m001() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/M001.py"),
+            &settings::Settings::for_rules(vec![CheckCode::M001, CheckCode::E501, CheckCode::F841]),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -778,12 +624,7 @@ mod tests {
     fn r001() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/R001.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::R001]),
-            },
+            &settings::Settings::for_rule(CheckCode::R001),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -795,12 +636,7 @@ mod tests {
     fn r002() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/R002.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::R002]),
-            },
+            &settings::Settings::for_rule(CheckCode::R002),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -812,12 +648,7 @@ mod tests {
     fn init() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/__init__.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F821, CheckCode::F822]),
-            },
+            &settings::Settings::for_rules(vec![CheckCode::F821, CheckCode::F822]),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -829,12 +660,7 @@ mod tests {
     fn future_annotations() -> Result<()> {
         let mut checks = check_path(
             Path::new("./resources/test/fixtures/future_annotations.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F401, CheckCode::F821]),
-            },
+            &settings::Settings::for_rules(vec![CheckCode::F401, CheckCode::F821]),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);

src/main.rs

@@ -25,6 +25,7 @@ use ::ruff::printer::{Printer, SerializationFormat};
 use ::ruff::pyproject;
 use ::ruff::settings::{FilePattern, Settings};
 use ::ruff::tell_user;
+use ruff::linter::add_noqa_to_path;
 
 const CARGO_PKG_NAME: &str = env!("CARGO_PKG_NAME");
 const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -57,9 +58,15 @@ struct Cli {
     /// List of error codes to enable.
     #[clap(long, multiple = true)]
     select: Vec<CheckCode>,
+    /// Like --select, but adds additional error codes on top of the selected ones.
+    #[clap(long, multiple = true)]
+    extend_select: Vec<CheckCode>,
     /// List of error codes to ignore.
     #[clap(long, multiple = true)]
     ignore: Vec<CheckCode>,
+    /// Like --ignore, but adds additional error codes on top of the ignored ones.
+    #[clap(long, multiple = true)]
+    extend_ignore: Vec<CheckCode>,
     /// List of paths, used to exclude files and/or directories from checks.
     #[clap(long, multiple = true)]
     exclude: Vec<String>,
@@ -69,6 +76,15 @@ struct Cli {
     /// Output serialization format for error messages.
     #[clap(long, arg_enum, default_value_t=SerializationFormat::Text)]
     format: SerializationFormat,
+    /// See the files ruff will be run against with the current settings.
+    #[clap(long, action)]
+    show_files: bool,
+    /// See ruff's settings.
+    #[clap(long, action)]
+    show_settings: bool,
+    /// Enable automatic additions of noqa directives to failing lines.
+    #[clap(long, action)]
+    add_noqa: bool,
 }
 
 #[cfg(feature = "update-informer")]
@@ -95,6 +111,22 @@ fn check_for_updates() {
     }
 }
 
+fn show_settings(settings: &Settings) {
+    println!("{:#?}", settings);
+}
+
+fn show_files(files: &[PathBuf], settings: &Settings) {
+    let mut entries: Vec<DirEntry> = files
+        .iter()
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flatten()
+        .collect();
+    entries.sort_by(|a, b| a.path().cmp(b.path()));
+    for entry in entries {
+        println!("{}", entry.path().to_string_lossy());
+    }
+}
+
 fn run_once(
     files: &[PathBuf],
     settings: &Settings,
@@ -155,6 +187,35 @@ fn run_once(
     Ok(messages)
 }
 
+fn add_noqa(files: &[PathBuf], settings: &Settings) -> Result<usize> {
+    // Collect all the files to check.
+    let start = Instant::now();
+    let paths: Vec<Result<DirEntry, walkdir::Error>> = files
+        .iter()
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .collect();
+    let duration = start.elapsed();
+    debug!("Identified files to lint in: {:?}", duration);
+
+    let start = Instant::now();
+    let modifications: usize = paths
+        .par_iter()
+        .map(|entry| match entry {
+            Ok(entry) => {
+                let path = entry.path();
+                add_noqa_to_path(path, settings)
+            }
+            Err(_) => Ok(0),
+        })
+        .flatten()
+        .sum();
+
+    let duration = start.elapsed();
+    debug!("Added noqa to files in: {:?}", duration);
+
+    Ok(modifications)
+}
+
 fn inner_main() -> Result<ExitCode> {
     let cli = Cli::parse();
 
@@ -173,26 +234,49 @@ fn inner_main() -> Result<ExitCode> {
     };
 
     // Parse the settings from the pyproject.toml and command-line arguments.
-    let mut settings = Settings::from_pyproject(&pyproject, &project_root);
+    let exclude: Vec<FilePattern> = cli
+        .exclude
+        .iter()
+        .map(|path| FilePattern::from_user(path, &project_root))
+        .collect();
+    let extend_exclude: Vec<FilePattern> = cli
+        .extend_exclude
+        .iter()
+        .map(|path| FilePattern::from_user(path, &project_root))
+        .collect();
+
+    let mut settings = Settings::from_pyproject(pyproject, project_root);
+    if !exclude.is_empty() {
+        settings.exclude = exclude;
+    }
+    if !extend_exclude.is_empty() {
+        settings.extend_exclude = extend_exclude;
+    }
     if !cli.select.is_empty() {
+        settings.clear();
         settings.select(cli.select);
     }
+    if !cli.extend_select.is_empty() {
+        settings.select(cli.extend_select);
+    }
     if !cli.ignore.is_empty() {
         settings.ignore(&cli.ignore);
     }
-    if !cli.exclude.is_empty() {
-        settings.exclude = cli
-            .exclude
-            .iter()
-            .map(|path| FilePattern::from_user(path, &project_root))
-            .collect();
+    if !cli.extend_ignore.is_empty() {
+        settings.ignore(&cli.extend_ignore);
     }
-    if !cli.extend_exclude.is_empty() {
-        settings.extend_exclude = cli
-            .extend_exclude
-            .iter()
-            .map(|path| FilePattern::from_user(path, &project_root))
-            .collect();
+
+    if cli.show_settings && cli.show_files {
+        println!("Error: specify --show-settings or show-files (not both).");
+        return Ok(ExitCode::FAILURE);
+    }
+    if cli.show_settings {
+        show_settings(&settings);
+        return Ok(ExitCode::SUCCESS);
+    }
+    if cli.show_files {
+        show_files(&cli.files, &settings);
+        return Ok(ExitCode::SUCCESS);
     }
 
     cache::init()?;
@@ -203,6 +287,10 @@ fn inner_main() -> Result<ExitCode> {
             println!("Warning: --fix is not enabled in watch mode.");
         }
 
+        if cli.add_noqa {
+            println!("Warning: --no-qa is not enabled in watch mode.");
+        }
+
         if cli.format != SerializationFormat::Text {
             println!("Warning: --format 'text' is used in watch mode.");
         }
@@ -241,6 +329,11 @@ fn inner_main() -> Result<ExitCode> {
                 Err(e) => return Err(e.into()),
             }
         }
+    } else if cli.add_noqa {
+        let modifications = add_noqa(&cli.files, &settings)?;
+        if modifications > 0 {
+            println!("Added {modifications} noqa directives.");
+        }
     } else {
         let messages = run_once(&cli.files, &settings, !cli.no_cache, cli.fix)?;
         if !cli.quiet {

src/noqa.rs

@@ -0,0 +1,280 @@
+use std::cmp::{max, min};
+
+use crate::checks::{Check, CheckCode};
+use anyhow::Result;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use rustpython_parser::lexer::{LexResult, Tok};
+use std::collections::{BTreeMap, BTreeSet};
+use std::fs;
+use std::path::Path;
+
+static NO_QA_REGEX: Lazy<Regex> = Lazy::new(|| {
+    Regex::new(r"(?i)(?P<noqa>\s*# noqa(?::\s?(?P<codes>([A-Z]+[0-9]+(?:[,\s]+)?)+))?)")
+        .expect("Invalid regex")
+});
+static SPLIT_COMMA_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").expect("Invalid regex"));
+
+#[derive(Debug)]
+pub enum Directive<'a> {
+    None,
+    All(usize),
+    Codes(usize, Vec<&'a str>),
+}
+
+pub fn extract_noqa_directive(line: &str) -> Directive {
+    match NO_QA_REGEX.captures(line) {
+        Some(caps) => match caps.name("noqa") {
+            Some(noqa) => match caps.name("codes") {
+                Some(codes) => Directive::Codes(
+                    noqa.start(),
+                    SPLIT_COMMA_REGEX
+                        .split(codes.as_str())
+                        .map(|code| code.trim())
+                        .filter(|code| !code.is_empty())
+                        .collect(),
+                ),
+                None => Directive::All(noqa.start()),
+            },
+            None => Directive::None,
+        },
+        None => Directive::None,
+    }
+}
+
+pub fn extract_noqa_line_for(lxr: &[LexResult]) -> Vec<usize> {
+    let mut noqa_line_for: Vec<usize> = vec![];
+
+    let mut last_is_string = false;
+    let mut last_seen = usize::MIN;
+    let mut min_line = usize::MAX;
+    let mut max_line = usize::MIN;
+
+    for (start, tok, end) in lxr.iter().flatten() {
+        if matches!(tok, Tok::EndOfFile) {
+            break;
+        }
+
+        if matches!(tok, Tok::Newline) {
+            min_line = min(min_line, start.row());
+            max_line = max(max_line, start.row());
+
+            // For now, we only care about preserving noqa directives across multi-line strings.
+            if last_is_string {
+                noqa_line_for.extend(vec![max_line; (max_line + 1) - min_line]);
+            } else {
+                for i in (min_line - 1)..(max_line) {
+                    noqa_line_for.push(i + 1);
+                }
+            }
+
+            min_line = usize::MAX;
+            max_line = usize::MIN;
+        } else {
+            // Handle empty lines.
+            if start.row() > last_seen {
+                for i in last_seen..(start.row() - 1) {
+                    noqa_line_for.push(i + 1);
+                }
+            }
+
+            min_line = min(min_line, start.row());
+            max_line = max(max_line, end.row());
+        }
+        last_seen = start.row();
+        last_is_string = matches!(tok, Tok::String { .. });
+    }
+
+    noqa_line_for
+}
+
+fn add_noqa_inner(
+    checks: &Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+) -> Result<(usize, String)> {
+    let lines: Vec<&str> = contents.lines().collect();
+    let mut matches_by_line: BTreeMap<usize, BTreeSet<&CheckCode>> = BTreeMap::new();
+    for lineno in 0..lines.len() {
+        let mut codes: BTreeSet<&CheckCode> = BTreeSet::new();
+        for check in checks {
+            if check.location.row() == lineno + 1 {
+                codes.insert(check.kind.code());
+            }
+        }
+
+        // Grab the noqa (logical) line number for the current (physical) line.
+        // If there are newlines at the end of the file, they won't be represented in
+        // `noqa_line_for`, so fallback to the current line.
+        let noqa_lineno = noqa_line_for
+            .get(lineno)
+            .map(|lineno| lineno - 1)
+            .unwrap_or(lineno);
+
+        if !codes.is_empty() {
+            let matches = matches_by_line
+                .entry(noqa_lineno)
+                .or_insert_with(BTreeSet::new);
+            matches.append(&mut codes);
+        }
+    }
+
+    let mut count: usize = 0;
+    let mut output = "".to_string();
+    for (lineno, line) in lines.iter().enumerate() {
+        match matches_by_line.get(&lineno) {
+            None => {
+                output.push_str(line);
+                output.push('\n');
+            }
+            Some(codes) => {
+                match extract_noqa_directive(line) {
+                    Directive::None => {
+                        output.push_str(line);
+                    }
+                    Directive::All(start) => output.push_str(&line[..start]),
+                    Directive::Codes(start, _) => output.push_str(&line[..start]),
+                };
+                let codes: Vec<&str> = codes.iter().map(|code| code.as_str()).collect();
+                output.push_str("  # noqa: ");
+                output.push_str(&codes.join(", "));
+                output.push('\n');
+                count += 1;
+            }
+        }
+    }
+
+    Ok((count, output))
+}
+
+pub fn add_noqa(
+    checks: &Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+    path: &Path,
+) -> Result<usize> {
+    let (count, output) = add_noqa_inner(checks, contents, noqa_line_for)?;
+    fs::write(path, output)?;
+    Ok(count)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::checks::{Check, CheckKind};
+    use anyhow::Result;
+    use rustpython_parser::ast::Location;
+    use rustpython_parser::lexer;
+    use rustpython_parser::lexer::LexResult;
+
+    use crate::noqa::{add_noqa_inner, extract_noqa_line_for};
+
+    #[test]
+    fn extraction() -> Result<()> {
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = 2
+z = x + 1",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "
+x = 1
+y = 2
+z = x + 1",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = 2
+z = x + 1
+        ",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+
+y = 2
+z = x + 1
+        ",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = '''abc
+def
+ghi
+'''
+y = 2
+z = x + 1",
+        )
+        .collect();
+        assert_eq!(extract_noqa_line_for(&lxr), vec![4, 4, 4, 4, 5, 6]);
+
+        Ok(())
+    }
+
+    #[test]
+    fn modification() -> Result<()> {
+        let checks = vec![];
+        let contents = "x = 1";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 0);
+        assert_eq!(output.trim(), contents.trim());
+
+        let checks = vec![Check::new(
+            CheckKind::UnusedVariable("x".to_string()),
+            Location::new(1, 1),
+        )];
+        let contents = "x = 1";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: F841".trim());
+
+        let checks = vec![
+            Check::new(
+                CheckKind::AmbiguousVariableName("x".to_string()),
+                Location::new(1, 1),
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Location::new(1, 1),
+            ),
+        ];
+        let contents = "x = 1  # noqa: E741";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
+
+        let checks = vec![
+            Check::new(
+                CheckKind::AmbiguousVariableName("x".to_string()),
+                Location::new(1, 1),
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Location::new(1, 1),
+            ),
+        ];
+        let contents = "x = 1  # noqa";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
+
+        Ok(())
+    }
+}

src/settings.rs

@@ -5,7 +5,7 @@ use std::path::{Path, PathBuf};
 use glob::Pattern;
 use once_cell::sync::Lazy;
 
-use crate::checks::{CheckCode, ALL_CHECK_CODES};
+use crate::checks::{CheckCode, DEFAULT_CHECK_CODES};
 use crate::fs;
 use crate::pyproject::load_config;
 
@@ -36,12 +36,38 @@ impl FilePattern {
 
 #[derive(Debug)]
 pub struct Settings {
+    pub pyproject: Option<PathBuf>,
+    pub project_root: Option<PathBuf>,
     pub line_length: usize,
     pub exclude: Vec<FilePattern>,
     pub extend_exclude: Vec<FilePattern>,
     pub select: BTreeSet<CheckCode>,
 }
 
+impl Settings {
+    pub fn for_rule(check_code: CheckCode) -> Self {
+        Self {
+            pyproject: None,
+            project_root: None,
+            line_length: 88,
+            exclude: vec![],
+            extend_exclude: vec![],
+            select: BTreeSet::from([check_code]),
+        }
+    }
+
+    pub fn for_rules(check_codes: Vec<CheckCode>) -> Self {
+        Self {
+            pyproject: None,
+            project_root: None,
+            line_length: 88,
+            exclude: vec![],
+            extend_exclude: vec![],
+            select: BTreeSet::from_iter(check_codes),
+        }
+    }
+}
+
 impl Hash for Settings {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.line_length.hash(state);
@@ -76,8 +102,8 @@ static DEFAULT_EXCLUDE: Lazy<Vec<FilePattern>> = Lazy::new(|| {
 });
 
 impl Settings {
-    pub fn from_pyproject(path: &Option<PathBuf>, project_root: &Option<PathBuf>) -> Self {
-        let config = load_config(path);
+    pub fn from_pyproject(pyproject: Option<PathBuf>, project_root: Option<PathBuf>) -> Self {
+        let config = load_config(&pyproject);
         let mut settings = Settings {
             line_length: config.line_length.unwrap_or(88),
             exclude: config
@@ -85,7 +111,7 @@ impl Settings {
                 .map(|paths| {
                     paths
                         .iter()
-                        .map(|path| FilePattern::from_user(path, project_root))
+                        .map(|path| FilePattern::from_user(path, &project_root))
                         .collect()
                 })
                 .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
@@ -94,15 +120,17 @@ impl Settings {
                 .map(|paths| {
                     paths
                         .iter()
-                        .map(|path| FilePattern::from_user(path, project_root))
+                        .map(|path| FilePattern::from_user(path, &project_root))
                         .collect()
                 })
                 .unwrap_or_default(),
             select: if let Some(select) = config.select {
                 BTreeSet::from_iter(select)
             } else {
-                BTreeSet::from_iter(ALL_CHECK_CODES)
+                BTreeSet::from_iter(DEFAULT_CHECK_CODES)
             },
+            pyproject,
+            project_root,
         };
         if let Some(ignore) = &config.ignore {
             settings.ignore(ignore);
@@ -110,8 +138,11 @@ impl Settings {
         settings
     }
 
-    pub fn select(&mut self, codes: Vec<CheckCode>) {
+    pub fn clear(&mut self) {
         self.select.clear();
+    }
+
+    pub fn select(&mut self, codes: Vec<CheckCode>) {
         for code in codes {
             self.select.insert(code);
         }

src/snapshots/ruff__linter__tests__m001.snap

@@ -0,0 +1,89 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnusedNOQA: ~
+  location:
+    row: 9
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