improve handling of EOF in noqa

crates/ruff_linter/src/noqa.rs

@@ -664,6 +664,7 @@ impl Ranged for NoqaDirectiveLine<'_> {
 #[derive(Debug, Default)]
 pub(crate) struct NoqaDirectives<'a> {
     inner: Vec<NoqaDirectiveLine<'a>>,
+    last_directive_includes_eof: bool,
 }
 
 impl<'a> NoqaDirectives<'a> {
@@ -694,14 +695,17 @@ impl<'a> NoqaDirectives<'a> {
             }
         }
 
-        // Extend a mapping at the end of the file to also include the EOF token.
-        if let Some(last) = directives.last_mut() {
-            if last.range.end() == locator.contents().text_len() {
-                last.range = last.range.add_end(TextSize::from(1));
-            }
-        }
+        // Record whether last directive should include EOF token.
+        let last_directive_includes_eof = if let Some(last) = directives.last() {
+            last.range.end() == locator.contents().text_len()
+        } else {
+            false
+        };
 
-        Self { inner: directives }
+        Self {
+            inner: directives,
+            last_directive_includes_eof,
+        }
     }
 
     pub(crate) fn find_line_with_directive(&self, offset: TextSize) -> Option<&NoqaDirectiveLine> {
@@ -720,17 +724,26 @@ impl<'a> NoqaDirectives<'a> {
     }
 
     fn find_line_index(&self, offset: TextSize) -> Option<usize> {
-        self.inner
-            .binary_search_by(|directive| {
-                if directive.range.end() < offset {
-                    std::cmp::Ordering::Less
-                } else if directive.range.contains(offset) {
-                    std::cmp::Ordering::Equal
+        let index = self.inner.binary_search_by(|directive| {
+            if directive.range.end() < offset {
+                std::cmp::Ordering::Less
+            } else if directive.range.contains(offset) {
+                std::cmp::Ordering::Equal
+            } else {
+                std::cmp::Ordering::Greater
+            }
+        });
+
+        match index {
+            Ok(index) => Some(index),
+            Err(index) => {
+                if self.last_directive_includes_eof && index == self.inner.len() - 1 {
+                    Some(index)
                 } else {
-                    std::cmp::Ordering::Greater
+                    None
                 }
-            })
-            .ok()
+            }
+        }
     }
 
     pub(crate) fn lines(&self) -> &[NoqaDirectiveLine] {

crates/ruff_linter/src/rules/pygrep_hooks/rules/blanket_noqa.rs

@@ -2,7 +2,7 @@ use ruff_diagnostics::{Diagnostic, Edit, Fix, FixAvailability, Violation};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_trivia::Cursor;
 use ruff_source_file::Locator;
-use ruff_text_size::{Ranged, TextLen, TextRange};
+use ruff_text_size::{Ranged, TextRange};
 
 use crate::noqa::{Directive, NoqaDirectives};
 
@@ -88,14 +88,8 @@ pub(crate) fn blanket_noqa(
 ) {
     for directive_line in noqa_directives.lines() {
         if let Directive::All(all) = &directive_line.directive {
-            let line = if directive_line.end() > locator.contents().text_len() {
-                let range = TextRange::new(directive_line.start(), locator.contents().text_len());
-                locator.slice(range)
-            } else {
-                locator.slice(directive_line)
-            };
-            let offset = directive_line.start();
-            let noqa_end = all.end() - offset;
+            let line = locator.slice(directive_line);
+            let noqa_end = all.end() - directive_line.start();
 
             // Skip the `# noqa`, plus any trailing whitespace.
             let mut cursor = Cursor::new(&line[noqa_end.to_usize()..]);