Use transformed source code for diagnostic locations

Untitled.ipynb

@@ -0,0 +1,73 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "54a242d2-f4cf-40dd-8a48-8c08856f9716",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1\n"
+     ]
+    }
+   ],
+   "source": [
+    "print(1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "8492efd7-5c96-40ab-8afb-8e0a6fff4bc7",
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "NameError",
+     "evalue": "name 'x' is not defined",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mNameError\u001b[0m                                 Traceback (most recent call last)",
+      "Cell \u001b[0;32mIn[7], line 2\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[38;5;28;01mimport\u001b[39;00m \u001b[38;5;21;01msys\u001b[39;00m\n\u001b[0;32m----> 2\u001b[0m \u001b[38;5;28mprint\u001b[39m(\u001b[43mx\u001b[49m)\n",
+      "\u001b[0;31mNameError\u001b[0m: name 'x' is not defined"
+     ]
+    }
+   ],
+   "source": [
+    "print(x)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "25e31239-d707-4096-b9be-c55b46966c02",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.12.0"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

crates/ruff_cli/src/diagnostics.rs

@@ -1,5 +1,6 @@
 #![cfg_attr(target_family = "wasm", allow(dead_code))]
 
+use std::borrow::Cow;
 use std::fs::File;
 use std::io;
 use std::ops::{Add, AddAssign};
@@ -273,6 +274,7 @@ pub(crate) fn lint_path(
             data: (messages, imports),
             error: parse_error,
         },
+        transformed,
         fixed,
     ) = if matches!(fix_mode, flags::FixMode::Apply | flags::FixMode::Diff) {
         if let Ok(FixerResult {
@@ -301,7 +303,12 @@ pub(crate) fn lint_path(
                     flags::FixMode::Generate => {}
                 }
             }
-            (result, fixed)
+            let transformed = if let Cow::Owned(transformed) = transformed {
+                transformed
+            } else {
+                source_kind
+            };
+            (result, transformed, fixed)
         } else {
             // If we fail to fix, lint the original source code.
             let result = lint_only(
@@ -313,8 +320,9 @@ pub(crate) fn lint_path(
                 source_type,
                 ParseSource::None,
             );
+            let transformed = source_kind;
             let fixed = FxHashMap::default();
-            (result, fixed)
+            (result, transformed, fixed)
         }
     } else {
         let result = lint_only(
@@ -326,16 +334,17 @@ pub(crate) fn lint_path(
             source_type,
             ParseSource::None,
         );
+        let transformed = source_kind;
         let fixed = FxHashMap::default();
-        (result, fixed)
+        (result, transformed, fixed)
     };
 
     let imports = imports.unwrap_or_default();
 
     if let Some((cache, relative_path, key)) = caching {
         // We don't cache parsing errors.
         if parse_error.is_none() {
-            // `FixMode::Generate` and `FixMode::Diff` rely on side-effects (writing to disk,
+            // `FixMode::Apply` and `FixMode::Diff` rely on side-effects (writing to disk,
             // and writing the diff to stdout, respectively). If a file has diagnostics, we
             // need to avoid reading from and writing to the cache in these modes.
             if match fix_mode {
@@ -350,7 +359,7 @@ pub(crate) fn lint_path(
                     LintCacheData::from_messages(
                         &messages,
                         imports.clone(),
-                        source_kind.as_ipy_notebook().map(Notebook::index).cloned(),
+                        transformed.as_ipy_notebook().map(Notebook::index).cloned(),
                     ),
                 );
             }
@@ -360,11 +369,11 @@ pub(crate) fn lint_path(
     if let Some(error) = parse_error {
         error!(
             "{}",
-            DisplayParseError::from_source_kind(error, Some(path.to_path_buf()), &source_kind,)
+            DisplayParseError::from_source_kind(error, Some(path.to_path_buf()), &transformed)
         );
     }
 
-    let notebook_indexes = if let SourceKind::IpyNotebook(notebook) = source_kind {
+    let notebook_indexes = if let SourceKind::IpyNotebook(notebook) = transformed {
         FxHashMap::from_iter([(path.to_string_lossy().to_string(), notebook.into_index())])
     } else {
         FxHashMap::default()
@@ -415,6 +424,7 @@ pub(crate) fn lint_stdin(
             data: (messages, imports),
             error: parse_error,
         },
+        transformed,
         fixed,
     ) = if matches!(fix_mode, flags::FixMode::Apply | flags::FixMode::Diff) {
         if let Ok(FixerResult {
@@ -443,8 +453,12 @@ pub(crate) fn lint_stdin(
                 }
                 flags::FixMode::Generate => {}
             }
-
-            (result, fixed)
+            let transformed = if let Cow::Owned(transformed) = transformed {
+                transformed
+            } else {
+                source_kind
+            };
+            (result, transformed, fixed)
         } else {
             // If we fail to fix, lint the original source code.
             let result = lint_only(
@@ -456,14 +470,15 @@ pub(crate) fn lint_stdin(
                 source_type,
                 ParseSource::None,
             );
-            let fixed = FxHashMap::default();
 
             // Write the contents to stdout anyway.
             if fix_mode.is_apply() {
                 source_kind.write(&mut io::stdout().lock())?;
             }
 
-            (result, fixed)
+            let transformed = source_kind;
+            let fixed = FxHashMap::default();
+            (result, transformed, fixed)
         }
     } else {
         let result = lint_only(
@@ -475,8 +490,9 @@ pub(crate) fn lint_stdin(
             source_type,
             ParseSource::None,
         );
+        let transformed = source_kind;
         let fixed = FxHashMap::default();
-        (result, fixed)
+        (result, transformed, fixed)
     };
 
     let imports = imports.unwrap_or_default();
@@ -488,7 +504,7 @@ pub(crate) fn lint_stdin(
         );
     }
 
-    let notebook_indexes = if let SourceKind::IpyNotebook(notebook) = source_kind {
+    let notebook_indexes = if let SourceKind::IpyNotebook(notebook) = transformed {
         FxHashMap::from_iter([(
             path.map_or_else(|| "-".into(), |path| path.to_string_lossy().to_string()),
             notebook.into_index(),

crates/ruff_linter/src/rules/pycodestyle/rules/missing_newline_at_end_of_file.rs

@@ -48,9 +48,6 @@ pub(crate) fn no_newline_at_end_of_file(
     }
 
     if !source.ends_with(['\n', '\r']) {
-        // Note: if `lines.last()` is `None`, then `contents` is empty (and so we don't
-        // want to raise W292 anyway).
-        // Both locations are at the end of the file (and thus the same).
         let range = TextRange::empty(locator.contents().text_len());
 
         let mut diagnostic = Diagnostic::new(MissingNewlineAtEndOfFile, range);
@@ -60,5 +57,6 @@ pub(crate) fn no_newline_at_end_of_file(
         )));
         return Some(diagnostic);
     }
+
     None
 }