Prototype filtering diagnostics by range suppressions

Author: amyreese

crates/ruff_linter/src/linter.rs

@@ -139,9 +139,6 @@ pub fn check_path(
     let tokens = parsed.tokens();
     let comment_ranges = indexer.comment_ranges();
 
-    // Gather all ruff:directive suppressions
-    let _suppressions = Suppressions::from_tokens(locator.contents(), tokens);
-
     // Collect doc lines. This requires a rare mix of tokens (for comments) and AST
     // (for docstrings), which demands special-casing at this level.
     let use_doc_lines = context.is_rule_enabled(Rule::DocLineTooLong);
@@ -329,6 +326,14 @@ pub fn check_path(
         }
     }
 
+    // Apply range suppressions before noqa, so that #noqa on a line already covered by a range
+    // will be reported as unused noqa rather than unused range.
+    // TODO: check if enabled?
+    {
+        let suppressions = Suppressions::from_tokens(locator.contents(), tokens);
+        suppressions.filter_diagnostics(&mut context);
+    }
+
     // Enforce `noqa` directives.
     if noqa.is_enabled()
         || context

crates/ruff_linter/src/suppression.rs

@@ -8,6 +8,8 @@ use ruff_python_trivia::{Cursor, is_python_whitespace};
 use ruff_text_size::{Ranged, TextLen, TextRange, TextSize, TextSlice};
 use smallvec::{SmallVec, smallvec};
 
+use crate::checkers::ast::LintContext;
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 enum SuppressionAction {
     Disable,
@@ -101,6 +103,35 @@ impl Suppressions {
         let mut builder = SuppressionsBuilder::new(source);
         builder.load_from_tokens(tokens)
     }
+
+    /// Check reported diagnostics against the set of valid range suppressions, and remove any
+    /// diagnostics from the context that should be suppressed by those ranges.
+    pub(crate) fn filter_diagnostics(&self, context: &mut LintContext) {
+        let mut ignored: Vec<usize> = vec![];
+
+        'outer: for (index, diagnostic) in context.iter().enumerate() {
+            let Some(code) = diagnostic.secondary_code() else {
+                continue;
+            };
+            let Some(span) = diagnostic.primary_span() else {
+                continue;
+            };
+            let Some(range) = span.range() else {
+                continue;
+            };
+
+            for suppression in &self.valid {
+                if *code == suppression.code.as_str() && suppression.range.contains_range(range) {
+                    ignored.push(index);
+                    continue 'outer;
+                }
+            }
+        }
+
+        for index in ignored.iter().rev() {
+            context.as_mut_vec().swap_remove(*index);
+        }
+    }
 }
 
 #[derive(Default)]