New diagnostics for unused range suppressions

crates/ruff_linter/resources/test/fixtures/ruff/suppressions.py

@@ -54,3 +54,35 @@ def f():
     # ruff:disable[E741,F841]
     I = 1  # noqa: E741,F841
     # ruff:enable[E741,F841]
+
+
+def f():
+    # TODO: Duplicate codes should be counted as duplicate, not unused
+    # ruff: disable[F841, F841]
+    foo = 0
+
+
+def f():
+    # Overlapping range suppressions, one should be marked as used,
+    # and the other should trigger an unused suppression diagnostic
+    # ruff: disable[F841]
+    # ruff: disable[F841]
+    foo = 0
+
+
+def f():
+    # Multiple codes but only one is used
+    # ruff: disable[E741, F401, F841]
+    foo = 0
+
+
+def f():
+    # Multiple codes but only two are used
+    # ruff: disable[E741, F401, F841]
+    I = 0
+
+
+def f():
+    # Multiple codes but none are used
+    # ruff: disable[E741, F401, F841]
+    print("hello")

crates/ruff_linter/src/checkers/noqa.rs

@@ -119,6 +119,9 @@ pub(crate) fn check_noqa(
         }
     }
 
+    // Diagnostics for unused/invalid range suppressions
+    suppressions.check_suppressions(context, locator);
+
     // Enforce that the noqa directive was actually used (RUF100), unless RUF100 was itself
     // suppressed.
     if context.is_rule_enabled(Rule::UnusedNOQA)
@@ -140,8 +143,13 @@ pub(crate) fn check_noqa(
                 Directive::All(directive) => {
                     if matches.is_empty() {
                         let edit = delete_comment(directive.range(), locator);
-                        let mut diagnostic = context
-                            .report_diagnostic(UnusedNOQA { codes: None }, directive.range());
+                        let mut diagnostic = context.report_diagnostic(
+                            UnusedNOQA {
+                                codes: None,
+                                kind: ruff::rules::UnusedNOQAKind::Noqa,
+                            },
+                            directive.range(),
+                        );
                         diagnostic.add_primary_tag(ruff_db::diagnostic::DiagnosticTag::Unnecessary);
                         diagnostic.set_fix(Fix::safe_edit(edit));
                     }
@@ -236,6 +244,7 @@ pub(crate) fn check_noqa(
                                         .map(|code| (*code).to_string())
                                         .collect(),
                                 }),
+                                kind: ruff::rules::UnusedNOQAKind::Noqa,
                             },
                             directive.range(),
                         );

crates/ruff_linter/src/noqa.rs

@@ -879,7 +879,7 @@ fn find_noqa_comments<'a>(
     exemption: &'a FileExemption,
     directives: &'a NoqaDirectives,
     noqa_line_for: &NoqaMapping,
-    suppressions: &Suppressions,
+    suppressions: &'a Suppressions,
 ) -> Vec<Option<NoqaComment<'a>>> {
     // List of noqa comments, ordered to match up with `messages`
     let mut comments_by_line: Vec<Option<NoqaComment<'a>>> = vec![];

crates/ruff_linter/src/rules/ruff/rules/unused_noqa.rs

@@ -4,14 +4,29 @@ use ruff_macros::{ViolationMetadata, derive_message_formats};
 
 use crate::AlwaysFixableViolation;
 
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Default)]
 pub(crate) struct UnusedCodes {
     pub disabled: Vec<String>,
     pub duplicated: Vec<String>,
     pub unknown: Vec<String>,
     pub unmatched: Vec<String>,
 }
 
+#[derive(Debug, PartialEq, Eq)]
+pub(crate) enum UnusedNOQAKind {
+    Noqa,
+    Suppression,
+}
+
+impl UnusedNOQAKind {
+    fn as_str(&self) -> &str {
+        match self {
+            UnusedNOQAKind::Noqa => "`noqa` directive",
+            UnusedNOQAKind::Suppression => "suppression",
+        }
+    }
+}
+
 /// ## What it does
 /// Checks for `noqa` directives that are no longer applicable.
 ///
@@ -46,6 +61,7 @@ pub(crate) struct UnusedCodes {
 #[violation_metadata(stable_since = "v0.0.155")]
 pub(crate) struct UnusedNOQA {
     pub codes: Option<UnusedCodes>,
+    pub kind: UnusedNOQAKind,
 }
 
 impl AlwaysFixableViolation for UnusedNOQA {
@@ -95,16 +111,20 @@ impl AlwaysFixableViolation for UnusedNOQA {
                     ));
                 }
                 if codes_by_reason.is_empty() {
-                    "Unused `noqa` directive".to_string()
+                    format!("Unused {}", self.kind.as_str())
                 } else {
-                    format!("Unused `noqa` directive ({})", codes_by_reason.join("; "))
+                    format!(
+                        "Unused {} ({})",
+                        self.kind.as_str(),
+                        codes_by_reason.join("; ")
+                    )
                 }
             }
-            None => "Unused blanket `noqa` directive".to_string(),
+            None => format!("Unused blanket {}", self.kind.as_str()),
         }
     }
 
     fn fix_title(&self) -> String {
-        "Remove unused `noqa` directive".to_string()
+        format!("Remove unused {}", self.kind.as_str())
     }
 }