feat(core): improve @file autocomplete to prioritize filenames (#21064)

packages/cli/src/ui/hooks/useAtCompletion.test.ts

@@ -120,8 +120,8 @@ describe('useAtCompletion', () => {
 
       expect(result.current.suggestions.map((s) => s.value)).toEqual([
         'src/',
-        'src/components/',
         'src/index.js',
+        'src/components/',
         'src/components/Button.tsx',
       ]);
     });

packages/core/src/utils/filesearch/fileSearch.test.ts

@@ -421,6 +421,47 @@ describe('FileSearch', () => {
     );
   });
 
+  it('should prioritize filenames closer to the end of the path and shorter paths', async () => {
+    tmpDir = await createTmpDir({
+      src: {
+        'hooks.ts': '',
+        hooks: {
+          'index.ts': '',
+        },
+        utils: {
+          'hooks.tsx': '',
+        },
+        'hooks-dev': {
+          'test.ts': '',
+        },
+      },
+    });
+
+    const fileSearch = FileSearchFactory.create({
+      projectRoot: tmpDir,
+      fileDiscoveryService: new FileDiscoveryService(tmpDir, {
+        respectGitIgnore: false,
+        respectGeminiIgnore: false,
+      }),
+      ignoreDirs: [],
+      cache: false,
+      cacheTtl: 0,
+      enableRecursiveFileSearch: true,
+      enableFuzzySearch: true,
+    });
+
+    await fileSearch.initialize();
+    const results = await fileSearch.search('hooks');
+
+    // The order should prioritize matches closer to the end and shorter strings.
+    // FZF matches right-to-left.
+    expect(results[0]).toBe('src/hooks/');
+    expect(results[1]).toBe('src/hooks.ts');
+    expect(results[2]).toBe('src/utils/hooks.tsx');
+    expect(results[3]).toBe('src/hooks-dev/');
+    expect(results[4]).toBe('src/hooks/index.ts');
+    expect(results[5]).toBe('src/hooks-dev/test.ts');
+  });
   it('should return empty array when no matches are found', async () => {
     tmpDir = await createTmpDir({
       src: ['file1.js'],

packages/core/src/utils/filesearch/fileSearch.ts

@@ -13,6 +13,44 @@ import { AsyncFzf, type FzfResultItem } from 'fzf';
 import { unescapePath } from '../paths.js';
 import type { FileDiscoveryService } from '../../services/fileDiscoveryService.js';
 
+// Tiebreaker: Prefers shorter paths.
+const byLengthAsc = (a: { item: string }, b: { item: string }) =>
+  a.item.length - b.item.length;
+
+// Tiebreaker: Prefers matches at the start of the filename (basename prefix).
+const byBasenamePrefix = (
+  a: { item: string; positions: Set<number> },
+  b: { item: string; positions: Set<number> },
+) => {
+  const getBasenameStart = (p: string) => {
+    const trimmed = p.endsWith('/') ? p.slice(0, -1) : p;
+    return Math.max(trimmed.lastIndexOf('/'), trimmed.lastIndexOf('\\')) + 1;
+  };
+  const aDiff = Math.min(...a.positions) - getBasenameStart(a.item);
+  const bDiff = Math.min(...b.positions) - getBasenameStart(b.item);
+
+  const aIsFilenameMatch = aDiff >= 0;
+  const bIsFilenameMatch = bDiff >= 0;
+
+  if (aIsFilenameMatch && !bIsFilenameMatch) return -1;
+  if (!aIsFilenameMatch && bIsFilenameMatch) return 1;
+  if (aIsFilenameMatch && bIsFilenameMatch) return aDiff - bDiff;
+
+  return 0; // Both are directory matches, let subsequent tiebreakers decide.
+};
+
+// Tiebreaker: Prefers matches closer to the end of the path.
+const byMatchPosFromEnd = (
+  a: { item: string; positions: Set<number> },
+  b: { item: string; positions: Set<number> },
+) => {
+  const maxPosA = Math.max(-1, ...a.positions);
+  const maxPosB = Math.max(-1, ...b.positions);
+  const distA = a.item.length - maxPosA;
+  const distB = b.item.length - maxPosB;
+  return distA - distB;
+};
+
 export interface FileSearchOptions {
   projectRoot: string;
   ignoreDirs: string[];
@@ -192,6 +230,8 @@ class RecursiveFileSearch implements FileSearch {
       // files, because the v2 algorithm is just too slow in those cases.
       this.fzf = new AsyncFzf(this.allFiles, {
         fuzzy: this.allFiles.length > 20000 ? 'v1' : 'v2',
+        forward: false,
+        tiebreakers: [byBasenamePrefix, byMatchPosFromEnd, byLengthAsc],
       });
     }
   }