fix: prevent malformed tool diffs from breaking chat

Safely falls back to raw patch text for invalid diffs Protects individual tool parts from crashing the chat Covers malformed apply_patch and edit diff cases
2026-05-25 22:10:50 +03:00
parent b2f7373b79
commit e97bf0d9dc
3 changed files with 449 additions and 142 deletions
@@ -0,0 +1,85 @@
+import { describe, expect, test } from 'bun:test';
+
+import { getDiffPatchEntries, getRenderablePatchInfo } from './toolDiffUtils';
+
+const identity = (path: string) => path;
+
+describe('toolDiffUtils', () => {
+    test('treats raw apply_patch envelopes as text, not visual diffs', () => {
+        const entries = getDiffPatchEntries(undefined, [
+            '*** Begin Patch',
+            '*** Update File: src/app.ts',
+            '@@ -1 +1 @@',
+            '-old',
+            '+new',
+            '*** End Patch',
+        ].join('\n'), identity);
+
+        expect(entries).toHaveLength(1);
+        expect(entries[0]?.renderMode).toBe('text');
+        expect(entries[0]?.patch).toContain('*** Begin Patch');
+    });
+
+    test('splits multi-file unified patches into one renderable entry per file', () => {
+        const entries = getDiffPatchEntries(undefined, [
+            '--- a/src/a.ts',
+            '+++ b/src/a.ts',
+            '@@ -1 +1 @@',
+            '-old',
+            '+new',
+            '--- a/src/b.ts',
+            '+++ b/src/b.ts',
+            '@@ -1 +1 @@',
+            '-left',
+            '+right',
+        ].join('\n'), identity);
+
+        expect(entries.map((entry) => entry.renderMode)).toEqual(['diff', 'diff']);
+        expect(entries.map((entry) => entry.title)).toEqual(['src/a.ts', 'src/b.ts']);
+    });
+
+    test('uses metadata.files patches before top-level fallback diffs', () => {
+        const entries = getDiffPatchEntries({
+            files: [{
+                relativePath: 'src/file.ts',
+                patch: [
+                    '--- a/src/file.ts',
+                    '+++ b/src/file.ts',
+                    '@@ -1 +1 @@',
+                    '-old',
+                    '+new',
+                ].join('\n'),
+            }],
+        }, 'not a diff', identity);
+
+        expect(entries).toHaveLength(1);
+        expect(entries[0]?.renderMode).toBe('diff');
+        expect(entries[0]?.title).toBe('src/file.ts');
+    });
+
+    test('synthesizes headers for valid headerless hunks', () => {
+        const entries = getDiffPatchEntries(undefined, [
+            '@@ -1 +1 @@',
+            '-old',
+            '+new',
+        ].join('\n'), identity);
+
+        expect(entries).toHaveLength(1);
+        expect(entries[0]?.renderMode).toBe('diff');
+        expect(getRenderablePatchInfo(entries[0]?.patch ?? '')).not.toBeNull();
+    });
+
+    test('keeps malformed unified patches as text fallbacks', () => {
+        const entries = getDiffPatchEntries(undefined, [
+            '--- a/src/file.ts',
+            '+++ b/src/file.ts',
+            '@@',
+            '-old',
+            '+new',
+        ].join('\n'), identity);
+
+        expect(entries).toHaveLength(1);
+        expect(entries[0]?.renderMode).toBe('text');
+        expect(entries[0]?.patch).toContain('@@');
+    });
+});