Support negated patterns in [extend-]per-file-ignores

crates/ruff/tests/lint.rs

@@ -1168,3 +1168,83 @@ def func():
 
     Ok(())
 }
+
+/// Per-file selects via ! negation in per-file-ignores
+#[test]
+fn negated_per_file_ignores() -> Result<()> {
+    let tempdir = TempDir::new()?;
+    let ruff_toml = tempdir.path().join("ruff.toml");
+    fs::write(
+        &ruff_toml,
+        r#"
+[lint.per-file-ignores]
+"!selected.py" = ["RUF"]
+"#,
+    )?;
+    let selected = tempdir.path().join("selected.py");
+    fs::write(selected, "")?;
+    let ignored = tempdir.path().join("ignored.py");
+    fs::write(ignored, "")?;
+
+    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(STDIN_BASE_OPTIONS)
+        .arg("--config")
+        .arg(&ruff_toml)
+        .arg("--select")
+        .arg("RUF901")
+        .current_dir(&tempdir)
+        , @r###"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    selected.py:1:1: RUF901 [*] Hey this is a stable test rule with a safe fix.
+    Found 1 error.
+    [*] 1 fixable with the `--fix` option.
+
+    ----- stderr -----
+    "###);
+    Ok(())
+}
+
+#[test]
+fn negated_per_file_ignores_absolute() -> Result<()> {
+    let tempdir = TempDir::new()?;
+    let ruff_toml = tempdir.path().join("ruff.toml");
+    fs::write(
+        &ruff_toml,
+        r#"
+[lint.per-file-ignores]
+"!src/**.py" = ["RUF"]
+"#,
+    )?;
+    let src_dir = tempdir.path().join("src");
+    fs::create_dir(&src_dir)?;
+    let selected = src_dir.join("selected.py");
+    fs::write(selected, "")?;
+    let ignored = tempdir.path().join("ignored.py");
+    fs::write(ignored, "")?;
+
+    insta::with_settings!({filters => vec![
+        // Replace windows paths
+        (r"\\", "/"),
+    ]}, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .arg("--config")
+            .arg(&ruff_toml)
+            .arg("--select")
+            .arg("RUF901")
+            .current_dir(&tempdir)
+            , @r###"
+        success: false
+        exit_code: 1
+        ----- stdout -----
+        src/selected.py:1:1: RUF901 [*] Hey this is a stable test rule with a safe fix.
+        Found 1 error.
+        [*] 1 fixable with the `--fix` option.
+
+        ----- stderr -----
+        "###);
+    });
+    Ok(())
+}

crates/ruff_linter/src/fs.rs

@@ -9,24 +9,37 @@ use crate::registry::RuleSet;
 /// Create a set with codes matching the pattern/code pairs.
 pub(crate) fn ignores_from_path(
     path: &Path,
-    pattern_code_pairs: &[(GlobMatcher, GlobMatcher, RuleSet)],
+    pattern_code_pairs: &[(GlobMatcher, GlobMatcher, bool, RuleSet)],
 ) -> RuleSet {
     let file_name = path.file_name().expect("Unable to parse filename");
     pattern_code_pairs
         .iter()
-        .filter_map(|(absolute, basename, rules)| {
+        .filter_map(|(absolute, basename, negated, rules)| {
             if basename.is_match(file_name) {
-                debug!(
-                    "Adding per-file ignores for {:?} due to basename match on {:?}: {:?}",
-                    path,
-                    basename.glob().regex(),
-                    rules
-                );
-                Some(rules)
+                if *negated { None } else {
+                    debug!(
+                        "Adding per-file ignores for {:?} due to basename match on {:?}: {:?}",
+                        path,
+                        basename.glob().regex(),
+                        rules
+                    );
+                    Some(rules)
+                }
             } else if absolute.is_match(path) {
+                if *negated { None } else {
+                    debug!(
+                        "Adding per-file ignores for {:?} due to absolute match on {:?}: {:?}",
+                        path,
+                        absolute.glob().regex(),
+                        rules
+                    );
+                    Some(rules)
+                }
+            } else if *negated {
                 debug!(
-                    "Adding per-file ignores for {:?} due to absolute match on {:?}: {:?}",
+                    "Adding per-file ignores for {:?} due to negated pattern matching neither {:?} nor {:?}: {:?}",
                     path,
+                    basename.glob().regex(),
                     absolute.glob().regex(),
                     rules
                 );

crates/ruff_linter/src/settings/types.rs

@@ -296,13 +296,22 @@ impl CacheKey for FilePatternSet {
 pub struct PerFileIgnore {
     pub(crate) basename: String,
     pub(crate) absolute: PathBuf,
+    pub(crate) negated: bool,
     pub(crate) rules: RuleSet,
 }
 
 impl PerFileIgnore {
-    pub fn new(pattern: String, prefixes: &[RuleSelector], project_root: Option<&Path>) -> Self {
+    pub fn new(
+        mut pattern: String,
+        prefixes: &[RuleSelector],
+        project_root: Option<&Path>,
+    ) -> Self {
         // Rules in preview are included here even if preview mode is disabled; it's safe to ignore disabled rules
         let rules: RuleSet = prefixes.iter().flat_map(RuleSelector::all_rules).collect();
+        let negated = pattern.starts_with('!');
+        if negated {
+            pattern.drain(..1);
+        }
         let path = Path::new(&pattern);
         let absolute = match project_root {
             Some(project_root) => fs::normalize_path_to(path, project_root),
@@ -312,6 +321,7 @@ impl PerFileIgnore {
         Self {
             basename: pattern,
             absolute,
+            negated,
             rules,
         }
     }
@@ -593,7 +603,7 @@ pub type IdentifierPattern = glob::Pattern;
 #[derive(Debug, Clone, CacheKey, Default)]
 pub struct PerFileIgnores {
     // Ordered as (absolute path matcher, basename matcher, rules)
-    ignores: Vec<(GlobMatcher, GlobMatcher, RuleSet)>,
+    ignores: Vec<(GlobMatcher, GlobMatcher, bool, RuleSet)>,
 }
 
 impl PerFileIgnores {
@@ -609,7 +619,12 @@ impl PerFileIgnores {
                 // Construct basename matcher.
                 let basename = Glob::new(&per_file_ignore.basename)?.compile_matcher();
 
-                Ok((absolute, basename, per_file_ignore.rules))
+                Ok((
+                    absolute,
+                    basename,
+                    per_file_ignore.negated,
+                    per_file_ignore.rules,
+                ))
             })
             .collect();
         Ok(Self { ignores: ignores? })
@@ -622,10 +637,10 @@ impl Display for PerFileIgnores {
             write!(f, "{{}}")?;
         } else {
             writeln!(f, "{{")?;
-            for (absolute, basename, rules) in &self.ignores {
+            for (absolute, basename, negated, rules) in &self.ignores {
                 writeln!(
                     f,
-                    "\t{{ absolute = {absolute:#?}, basename = {basename:#?}, rules = {rules} }},"
+                    "\t{{ absolute = {absolute:#?}, basename = {basename:#?}, negated = {negated:#?}, rules = {rules} }},"
                 )?;
             }
             write!(f, "}}")?;
@@ -635,7 +650,7 @@ impl Display for PerFileIgnores {
 }
 
 impl Deref for PerFileIgnores {
-    type Target = Vec<(GlobMatcher, GlobMatcher, RuleSet)>;
+    type Target = Vec<(GlobMatcher, GlobMatcher, bool, RuleSet)>;
 
     fn deref(&self) -> &Self::Target {
         &self.ignores

crates/ruff_workspace/src/options.rs

@@ -905,7 +905,8 @@ pub struct LintCommonOptions {
 
     // Tables are required to go last.
     /// A list of mappings from file pattern to rule codes or prefixes to
-    /// exclude, when considering any matching files.
+    /// exclude, when considering any matching files. An initial '!' negates
+    /// the file pattern.
     #[option(
         default = "{}",
         value_type = "dict[str, list[RuleSelector]]",
@@ -914,6 +915,8 @@ pub struct LintCommonOptions {
             # Ignore `E402` (import violations) in all `__init__.py` files, and in `path/to/file.py`.
             "__init__.py" = ["E402"]
             "path/to/file.py" = ["E402"]
+            # Ignore `D` rules everywhere except for the `src/` directory.
+            "!src/**.py" = ["F401"]
         "#
     )]
     pub per_file_ignores: Option<FxHashMap<String, Vec<RuleSelector>>>,