fix: recover corrupted unified diff content

Author: AlexandrSuhinin

src/CodexToolCallMapper.ts

@@ -296,7 +296,8 @@ async function createUpdateFileContent(change: FileUpdateChange): Promise<ToolCa
     const oldContent = await readFile(change.path, { encoding: "utf8" }).catch(() => null);
     if (oldContent === null) return null;
 
-    const newContent = applyPatch(oldContent, change.diff);
+    const unifiedDiff = recoverCorruptedDiff(change.diff);
+    const newContent = applyPatch(oldContent, unifiedDiff);
     if (!newContent) return null;
 
     return {
@@ -327,6 +328,14 @@ async function createDeleteFileContent(change: FileUpdateChange): Promise<ToolCa
     }
 }
 
+/**
+ * Fix unified diff content corrupted by codex agent.
+ * Removes synthetic "Moved to" from the end.
+ */
+function recoverCorruptedDiff(diff: string): string {
+    return diff.replace(/\nMoved to: .*$/, "");
+}
+
 function isUnifiedDiff(content: string): boolean {
     return content.startsWith("--- ") || content.includes("\n--- ");
 }

src/__tests__/CodexACPAgent/file-change-events.test.ts

@@ -298,4 +298,40 @@ describe('CodexEventHandler - file change events', () => {
             content: [],
         });
     });
+
+    it('should parse update diffs with move metadata appended', async () => {
+        mockFileContent('/test/project/OriginalFile.kt', 'old code line\n');
+
+        const fileChange: ThreadItem = {
+            type: 'fileChange',
+            id: 'file-change-move-metadata',
+            changes: [
+                {
+                    path: '/test/project/OriginalFile.kt',
+                    kind: {
+                        type: 'update',
+                        move_path: '/test/project/NewFile.kt',
+                    },
+                    diff:
+`@@ -1 +1 @@
+-old code line
++new code line
+
+
+Moved to: /test/project/NewFile.kt`,
+                },
+            ],
+            status: 'inProgress',
+        };
+
+        const updateEvent = await createFileChangeUpdate(fileChange);
+        expect(updateEvent).toMatchObject({
+            content: [
+                {
+                    oldText: 'old code line\n',
+                    newText: 'new code line\n',
+                },
+            ],
+        });
+    });
 });