From c23bf395e2cb2d925aef83fa3e09a714f9c835ba Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Sun, 11 Aug 2024 19:23:33 -0400
Subject: [PATCH] Warn on invalid # noqa rule codes

---
 crates/ruff_linter/src/checkers/noqa.rs |  3 ++-
 crates/ruff_linter/src/noqa.rs          | 29 ++++++++++++++++++++++---
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/crates/ruff_linter/src/checkers/noqa.rs b/crates/ruff_linter/src/checkers/noqa.rs
index e893551dfc..f392f568cc 100644
--- a/crates/ruff_linter/src/checkers/noqa.rs
+++ b/crates/ruff_linter/src/checkers/noqa.rs
@@ -43,7 +43,8 @@ pub(crate) fn check_noqa(
     let exemption = FileExemption::from(&file_noqa_directives);
 
     // Extract all `noqa` directives.
-    let mut noqa_directives = NoqaDirectives::from_commented_ranges(comment_ranges, path, locator);
+    let mut noqa_directives =
+        NoqaDirectives::from_commented_ranges(comment_ranges, &settings.external, path, locator);
 
     // Indices of diagnostics that were ignored by a `noqa` directive.
     let mut ignored_diagnostics = vec![];
diff --git a/crates/ruff_linter/src/noqa.rs b/crates/ruff_linter/src/noqa.rs
index 7830330344..ebfc40823f 100644
--- a/crates/ruff_linter/src/noqa.rs
+++ b/crates/ruff_linter/src/noqa.rs
@@ -36,7 +36,7 @@ pub fn generate_noqa_edits(
     let file_directives =
         FileNoqaDirectives::extract(locator.contents(), comment_ranges, external, path, locator);
     let exemption = FileExemption::from(&file_directives);
-    let directives = NoqaDirectives::from_commented_ranges(comment_ranges, path, locator);
+    let directives = NoqaDirectives::from_commented_ranges(comment_ranges, external, path, locator);
     let comments = find_noqa_comments(diagnostics, locator, &exemption, &directives, noqa_line_for);
     build_noqa_edits_by_diagnostic(comments, locator, line_ending)
 }
@@ -623,7 +623,7 @@ fn add_noqa_inner(
         FileNoqaDirectives::extract(locator.contents(), comment_ranges, external, path, locator);
     let exemption = FileExemption::from(&directives);
 
-    let directives = NoqaDirectives::from_commented_ranges(comment_ranges, path, locator);
+    let directives = NoqaDirectives::from_commented_ranges(comment_ranges, external, path, locator);
 
     let comments = find_noqa_comments(diagnostics, locator, &exemption, &directives, noqa_line_for);
 
@@ -916,6 +916,7 @@ pub(crate) struct NoqaDirectives<'a> {
 impl<'a> NoqaDirectives<'a> {
     pub(crate) fn from_commented_ranges(
         comment_ranges: &CommentRanges,
+        external: &[String],
         path: &Path,
         locator: &'a Locator<'a>,
     ) -> Self {
@@ -930,7 +931,29 @@ impl<'a> NoqaDirectives<'a> {
                     warn!("Invalid `# noqa` directive on {path_display}:{line}: {err}");
                 }
                 Ok(Some(directive)) => {
-                    // noqa comments are guaranteed to be single line.
+                    if let Directive::Codes(codes) = &directive {
+                        // Warn on invalid rule codes.
+                        for code in &codes.codes {
+                            // Ignore externally-defined rules.
+                            if !external
+                                .iter()
+                                .any(|external| code.as_str().starts_with(external))
+                            {
+                                if Rule::from_code(
+                                    get_redirect_target(code.as_str()).unwrap_or(code.as_str()),
+                                )
+                                .is_err()
+                                {
+                                    #[allow(deprecated)]
+                                    let line = locator.compute_line_index(range.start());
+                                    let path_display = relativize_path(path);
+                                    warn!("Invalid rule code provided to `# noqa` at {path_display}:{line}: {code}");
+                                }
+                            }
+                        }
+                    }
+
+                    // `# noqa` comments are guaranteed to be single line.
                     let range = locator.line_range(range.start());
                     directives.push(NoqaDirectiveLine {
                         range,