takt: github-issue-188 (#190)

README.md

@@ -465,6 +465,7 @@ TAKT includes multiple builtin pieces:
 | `review-only` | Read-only code review piece that makes no changes. |
 | `structural-reform` | Full project review and structural reform: iterative codebase restructuring with staged file splits. |
 | `unit-test` | Unit test focused piece: test analysis → test implementation → review → fix. |
+| `e2e-test` | E2E test focused piece: E2E analysis → E2E implementation → review → fix (Vitest-based E2E flow). |
 
 **Per-persona provider overrides:** Use `persona_providers` in config to route specific personas to different providers (e.g., coder on Codex, reviewers on Claude) without duplicating pieces.
 

builtins/en/instructions/implement-e2e-test.md

@@ -0,0 +1,51 @@
+Implement E2E tests according to the test plan.
+Refer only to files within the Report Directory shown in the Piece Context. Do not search or reference other report directories.
+
+**Actions:**
+1. Review the test plan report
+2. Implement or update tests following existing E2E layout (e.g., `e2e/specs/`)
+3. Run E2E tests (minimum: `npm run test:e2e:mock`, and targeted spec runs when needed)
+4. If tests fail, analyze root cause, fix test or code, and rerun
+5. Confirm related existing tests are not broken
+
+**Constraints:**
+- Keep the current E2E framework (Vitest) unchanged
+- Keep one scenario per test and make assertions explicit
+- Reuse existing fixtures/helpers/mock strategy for external dependencies
+
+**Scope output contract (create at the start of implementation):**
+```markdown
+# Change Scope Declaration
+
+## Task
+{One-line task summary}
+
+## Planned changes
+| Type | File |
+|------|------|
+| Create | `e2e/specs/example.e2e.ts` |
+
+## Estimated size
+Small / Medium / Large
+
+## Impact area
+- {Affected modules or features}
+```
+
+**Decisions output contract (at implementation completion, only if decisions were made):**
+```markdown
+# Decision Log
+
+## 1. {Decision}
+- **Context**: {Why the decision was needed}
+- **Options considered**: {List of options}
+- **Rationale**: {Reason for the choice}
+```
+
+**Required output (include headings)**
+## Work results
+- {Summary of actions taken}
+## Changes made
+- {Summary of changes}
+## Test results
+- {Command executed and results}

builtins/en/instructions/plan-e2e-test.md

@@ -0,0 +1,11 @@
+Analyze the target code and identify missing E2E tests.
+
+**Note:** If a Previous Response exists, this is a replan due to rejection.
+Revise the test plan taking that feedback into account.
+
+**Actions:**
+1. Read target features, implementation, and existing E2E specs (`e2e/specs/**/*.e2e.ts`) to understand behavior
+2. Summarize current E2E coverage (happy path, failure path, regression points)
+3. Identify missing E2E scenarios with expected outcomes and observability points
+4. Specify execution commands (`npm run test:e2e:mock` and, when needed, `npx vitest run e2e/specs/<target>.e2e.ts`)
+5. Provide concrete guidance for failure analysis → fix → rerun workflow

builtins/en/piece-categories.yaml

@@ -11,6 +11,7 @@ piece_categories:
       - review-fix-minimal
       - review-only
       - unit-test
+      - e2e-test
   🎨 Frontend: {}
   ⚙️ Backend: {}
   🔧 Expert:

builtins/en/pieces/e2e-test.yaml

@@ -0,0 +1,236 @@
+name: e2e-test
+description: E2E test focused piece (E2E analysis → E2E implementation → review → fix)
+max_iterations: 20
+initial_movement: plan_test
+loop_monitors:
+  - cycle:
+      - ai_review
+      - ai_fix
+    threshold: 3
+    judge:
+      persona: supervisor
+      instruction_template: |
+        The ai_review ↔ ai_fix loop has repeated {cycle_count} times.
+
+        Review the reports from each cycle and determine whether this loop
+        is healthy (making progress) or unproductive (repeating the same issues).
+
+        **Reports to reference:**
+        - AI Review results: {report:04-ai-review.md}
+
+        **Judgment criteria:**
+        - Are new issues being found/fixed in each cycle?
+        - Are the same findings being repeated?
+        - Are fixes actually being applied?
+      rules:
+        - condition: Healthy (making progress)
+          next: ai_review
+        - condition: Unproductive (no improvement)
+          next: review_test
+movements:
+  - name: plan_test
+    edit: false
+    persona: test-planner
+    policy: testing
+    knowledge:
+      - architecture
+      - backend
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Bash
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: Test plan complete
+        next: implement_test
+      - condition: User is asking a question (not an E2E test task)
+        next: COMPLETE
+      - condition: Requirements unclear, insufficient info
+        next: ABORT
+        appendix: |
+          Clarifications needed:
+          - {Question 1}
+          - {Question 2}
+    instruction: plan-e2e-test
+    output_contracts:
+      report:
+        - name: 00-test-plan.md
+          format: test-plan
+
+  - name: implement_test
+    edit: true
+    persona: coder
+    policy:
+      - coding
+      - testing
+    session: refresh
+    knowledge:
+      - backend
+      - architecture
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Edit
+      - Write
+      - Bash
+      - WebSearch
+      - WebFetch
+    permission_mode: edit
+    rules:
+      - condition: Test implementation complete
+        next: ai_review
+      - condition: No implementation (report only)
+        next: ai_review
+      - condition: Cannot proceed, insufficient info
+        next: ai_review
+      - condition: User input required
+        next: implement_test
+        requires_user_input: true
+        interactive_only: true
+    instruction: implement-e2e-test
+    output_contracts:
+      report:
+        - Scope: 02-coder-scope.md
+        - Decisions: 03-coder-decisions.md
+
+  - name: ai_review
+    edit: false
+    persona: ai-antipattern-reviewer
+    policy:
+      - review
+      - ai-antipattern
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: No AI-specific issues
+        next: review_test
+      - condition: AI-specific issues found
+        next: ai_fix
+    instruction: ai-review
+    output_contracts:
+      report:
+        - name: 04-ai-review.md
+          format: ai-review
+
+  - name: ai_fix
+    edit: true
+    persona: coder
+    policy:
+      - coding
+      - testing
+    session: refresh
+    knowledge:
+      - backend
+      - architecture
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Edit
+      - Write
+      - Bash
+      - WebSearch
+      - WebFetch
+    permission_mode: edit
+    rules:
+      - condition: AI issues fixed
+        next: ai_review
+      - condition: No fix needed (verified target files/spec)
+        next: ai_no_fix
+      - condition: Cannot proceed, insufficient info
+        next: ai_no_fix
+    instruction: ai-fix
+
+  - name: ai_no_fix
+    edit: false
+    persona: architecture-reviewer
+    policy: review
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+    rules:
+      - condition: ai_review's findings are valid (fix required)
+        next: ai_fix
+      - condition: ai_fix's judgment is valid (no fix needed)
+        next: review_test
+    instruction: arbitrate
+
+  - name: review_test
+    edit: false
+    persona: qa-reviewer
+    policy:
+      - review
+      - qa
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: approved
+        next: supervise
+      - condition: needs_fix
+        next: fix
+    instruction: review-test
+    output_contracts:
+      report:
+        - name: 05-qa-review.md
+          format: qa-review
+
+  - name: fix
+    edit: true
+    persona: coder
+    policy:
+      - coding
+      - testing
+    session: refresh
+    knowledge:
+      - backend
+      - architecture
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Edit
+      - Write
+      - Bash
+      - WebSearch
+      - WebFetch
+    permission_mode: edit
+    rules:
+      - condition: Fix complete
+        next: review_test
+      - condition: Cannot proceed, insufficient info
+        next: plan_test
+    instruction: fix
+
+  - name: supervise
+    edit: false
+    persona: supervisor
+    policy: review
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Bash
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: All checks passed
+        next: COMPLETE
+      - condition: Requirements unmet, tests failing, build errors
+        next: plan_test
+    instruction: supervise
+    output_contracts:
+      report:
+        - Validation: 06-supervisor-validation.md
+        - Summary: summary.md

builtins/ja/instructions/implement-e2e-test.md

@@ -0,0 +1,51 @@
+テスト計画に従ってE2Eテストを実装してください。
+Piece Contextに示されたReport Directory内のファイルのみ参照してください。他のレポートディレクトリは検索/参照しないでください。
+
+**やること:**
+1. テスト計画のレポートを確認する
+2. `e2e/specs/` など既存E2E配置に従ってテストを実装・更新する
+3. E2Eテストを実行する（最低: `npm run test:e2e:mock`、必要に応じて対象specの単体実行）
+4. 失敗時は原因を特定し、テストまたは対象コードを修正して再実行する
+5. 既存の関連テストが壊れていないことを確認する
+
+**実装の制約:**
+- 既存のE2Eフレームワーク（Vitest）を変更しない
+- テストは1シナリオ1関心で記述し、期待結果を明確にする
+- 外部依存があるケースは既存のfixture/helper/mock方針に合わせる
+
+**Scope出力契約（実装開始時に作成）:**
+```markdown
+# 変更スコープ宣言
+
+## タスク
+{タスクの1行要約}
+
+## 変更予定
+| 種別 | ファイル |
+|------|---------|
+| 作成 | `e2e/specs/example.e2e.ts` |
+
+## 推定規模
+Small / Medium / Large
+
+## 影響範囲
+- {影響するモジュールや機能}
+```
+
+**Decisions出力契約（実装完了時、決定がある場合のみ）:**
+```markdown
+# 決定ログ
+
+## 1. {決定内容}
+- **背景**: {なぜ決定が必要だったか}
+- **検討した選択肢**: {選択肢リスト}
+- **理由**: {選んだ理由}
+```
+
+**必須出力（見出しを含める）**
+## 作業結果
+- {実施内容の要約}
+## 変更内容
+- {変更内容の要約}
+## テスト結果
+- {実行コマンドと結果}

builtins/ja/instructions/plan-e2e-test.md

@@ -0,0 +1,11 @@
+対象コードを分析し、不足しているE2Eテストを洗い出してください。
+
+**注意:** Previous Responseがある場合は差し戻しのため、
+その内容を踏まえてテスト計画を見直してください。
+
+**やること:**
+1. 対象機能の仕様・実装・既存E2Eテスト（`e2e/specs/**/*.e2e.ts`）を読み、振る舞いを理解する
+2. 既存E2Eテストのカバー範囲（正常系・異常系・回帰観点）を整理する
+3. 不足しているE2Eケースを洗い出す（シナリオ、期待結果、失敗時の観測点）
+4. 実行コマンドを明記する（`npm run test:e2e:mock` / 必要時 `npx vitest run e2e/specs/<target>.e2e.ts`）
+5. 実装者向けに、失敗解析→修正→再実行の手順を具体化する

builtins/ja/piece-categories.yaml

@@ -11,6 +11,7 @@ piece_categories:
       - review-fix-minimal
       - review-only
       - unit-test
+      - e2e-test
   🎨 フロントエンド: {}
   ⚙️ バックエンド: {}
   🔧 エキスパート:

builtins/ja/pieces/e2e-test.yaml

@@ -0,0 +1,236 @@
+name: e2e-test
+description: E2Eテスト追加に特化したピース（E2E分析→E2E実装→レビュー→修正）
+max_iterations: 20
+initial_movement: plan_test
+loop_monitors:
+  - cycle:
+      - ai_review
+      - ai_fix
+    threshold: 3
+    judge:
+      persona: supervisor
+      instruction_template: |
+        ai_review と ai_fix のループが {cycle_count} 回繰り返されました。
+
+        各サイクルのレポートを確認し、このループが健全（進捗がある）か、
+        非生産的（同じ問題を繰り返している）かを判断してください。
+
+        **参照するレポート:**
+        - AIレビュー結果: {report:04-ai-review.md}
+
+        **判断基準:**
+        - 各サイクルで新しい問題が発見・修正されているか
+        - 同じ指摘が繰り返されていないか
+        - 修正が実際に反映されているか
+      rules:
+        - condition: 健全（進捗あり）
+          next: ai_review
+        - condition: 非生産的（改善なし）
+          next: review_test
+movements:
+  - name: plan_test
+    edit: false
+    persona: test-planner
+    policy: testing
+    knowledge:
+      - architecture
+      - backend
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Bash
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: テスト計画が完了
+        next: implement_test
+      - condition: ユーザーが質問をしている（E2Eテスト追加タスクではない）
+        next: COMPLETE
+      - condition: 要件が不明確、情報不足
+        next: ABORT
+        appendix: |
+          確認事項:
+          - {質問1}
+          - {質問2}
+    instruction: plan-e2e-test
+    output_contracts:
+      report:
+        - name: 00-test-plan.md
+          format: test-plan
+
+  - name: implement_test
+    edit: true
+    persona: coder
+    policy:
+      - coding
+      - testing
+    session: refresh
+    knowledge:
+      - backend
+      - architecture
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Edit
+      - Write
+      - Bash
+      - WebSearch
+      - WebFetch
+    permission_mode: edit
+    rules:
+      - condition: テスト実装完了
+        next: ai_review
+      - condition: 実装未着手（レポートのみ）
+        next: ai_review
+      - condition: 判断できない、情報不足
+        next: ai_review
+      - condition: ユーザー入力が必要
+        next: implement_test
+        requires_user_input: true
+        interactive_only: true
+    instruction: implement-e2e-test
+    output_contracts:
+      report:
+        - Scope: 02-coder-scope.md
+        - Decisions: 03-coder-decisions.md
+
+  - name: ai_review
+    edit: false
+    persona: ai-antipattern-reviewer
+    policy:
+      - review
+      - ai-antipattern
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: AI特有の問題なし
+        next: review_test
+      - condition: AI特有の問題あり
+        next: ai_fix
+    instruction: ai-review
+    output_contracts:
+      report:
+        - name: 04-ai-review.md
+          format: ai-review
+
+  - name: ai_fix
+    edit: true
+    persona: coder
+    policy:
+      - coding
+      - testing
+    session: refresh
+    knowledge:
+      - backend
+      - architecture
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Edit
+      - Write
+      - Bash
+      - WebSearch
+      - WebFetch
+    permission_mode: edit
+    rules:
+      - condition: AI問題の修正完了
+        next: ai_review
+      - condition: 修正不要（指摘対象ファイル/仕様の確認済み）
+        next: ai_no_fix
+      - condition: 判断できない、情報不足
+        next: ai_no_fix
+    instruction: ai-fix
+
+  - name: ai_no_fix
+    edit: false
+    persona: architecture-reviewer
+    policy: review
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+    rules:
+      - condition: ai_reviewの指摘が妥当（修正すべき）
+        next: ai_fix
+      - condition: ai_fixの判断が妥当（修正不要）
+        next: review_test
+    instruction: arbitrate
+
+  - name: review_test
+    edit: false
+    persona: qa-reviewer
+    policy:
+      - review
+      - qa
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: approved
+        next: supervise
+      - condition: needs_fix
+        next: fix
+    instruction: review-test
+    output_contracts:
+      report:
+        - name: 05-qa-review.md
+          format: qa-review
+
+  - name: fix
+    edit: true
+    persona: coder
+    policy:
+      - coding
+      - testing
+    session: refresh
+    knowledge:
+      - backend
+      - architecture
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Edit
+      - Write
+      - Bash
+      - WebSearch
+      - WebFetch
+    permission_mode: edit
+    rules:
+      - condition: 修正完了
+        next: review_test
+      - condition: 判断できない、情報不足
+        next: plan_test
+    instruction: fix
+
+  - name: supervise
+    edit: false
+    persona: supervisor
+    policy: review
+    allowed_tools:
+      - Read
+      - Glob
+      - Grep
+      - Bash
+      - WebSearch
+      - WebFetch
+    rules:
+      - condition: すべて問題なし
+        next: COMPLETE
+      - condition: 要求未達成、テスト失敗、ビルドエラー
+        next: plan_test
+    instruction: supervise
+    output_contracts:
+      report:
+        - Validation: 06-supervisor-validation.md
+        - Summary: summary.md

docs/README.ja.md

@@ -465,6 +465,7 @@ TAKTには複数のビルトインピースが同梱されています:
 | `review-only` | 変更を加えない読み取り専用のコードレビューピース。 |
 | `structural-reform` | プロジェクト全体の構造改革: 段階的なファイル分割を伴う反復的なコードベース再構成。 |
 | `unit-test` | ユニットテスト重視ピース: テスト分析 → テスト実装 → レビュー → 修正。 |
+| `e2e-test` | E2Eテスト重視ピース: E2E分析 → E2E実装 → レビュー → 修正（VitestベースのE2Eフロー）。 |
 
 **ペルソナ別プロバイダー設定:** 設定ファイルの `persona_providers` で、特定のペルソナを異なるプロバイダーにルーティングできます（例: coder は Codex、レビュアーは Claude）。ピースを複製する必要はありません。
 

src/__tests__/config.test.ts

@@ -217,7 +217,7 @@ describe('loadPiece (builtin fallback)', () => {
     expect(piece).toBeNull();
   });
 
-  it('should load builtin pieces like minimal, research', () => {
+  it('should load builtin pieces like minimal, research, e2e-test', () => {
     const minimal = loadPiece('minimal', process.cwd());
     expect(minimal).not.toBeNull();
     expect(minimal!.name).toBe('minimal');
@@ -225,6 +225,10 @@ describe('loadPiece (builtin fallback)', () => {
     const research = loadPiece('research', process.cwd());
     expect(research).not.toBeNull();
     expect(research!.name).toBe('research');
+
+    const e2eTest = loadPiece('e2e-test', process.cwd());
+    expect(e2eTest).not.toBeNull();
+    expect(e2eTest!.name).toBe('e2e-test');
   });
 });
 
@@ -246,6 +250,7 @@ describe('listPieces (builtin fallback)', () => {
     const pieces = listPieces(testDir);
     expect(pieces).toContain('default');
     expect(pieces).toContain('minimal');
+    expect(pieces).toContain('e2e-test');
   });
 
   it('should return sorted list', () => {

src/__tests__/it-piece-loader.test.ts

@@ -14,10 +14,11 @@ import { join } from 'node:path';
 import { tmpdir } from 'node:os';
 
 // --- Mocks ---
+const languageState = vi.hoisted(() => ({ value: 'en' as 'en' | 'ja' }));
 
 vi.mock('../infra/config/global/globalConfig.js', () => ({
   loadGlobalConfig: vi.fn().mockReturnValue({}),
-  getLanguage: vi.fn().mockReturnValue('en'),
+  getLanguage: vi.fn(() => languageState.value),
   getDisabledBuiltins: vi.fn().mockReturnValue([]),
   getBuiltinPiecesEnabled: vi.fn().mockReturnValue(true),
 }));
@@ -40,6 +41,7 @@ describe('Piece Loader IT: builtin piece loading', () => {
 
   beforeEach(() => {
     testDir = createTestDir();
+    languageState.value = 'en';
   });
 
   afterEach(() => {
@@ -64,6 +66,39 @@ describe('Piece Loader IT: builtin piece loading', () => {
     const config = loadPiece('non-existent-piece-xyz', testDir);
     expect(config).toBeNull();
   });
+
+  it('should include and load e2e-test as a builtin piece', () => {
+    expect(builtinNames).toContain('e2e-test');
+
+    const config = loadPiece('e2e-test', testDir);
+    expect(config).not.toBeNull();
+
+    const planMovement = config!.movements.find((movement) => movement.name === 'plan_test');
+    const implementMovement = config!.movements.find((movement) => movement.name === 'implement_test');
+
+    expect(planMovement).toBeDefined();
+    expect(implementMovement).toBeDefined();
+    expect(planMovement!.instructionTemplate).toContain('missing E2E tests');
+    expect(implementMovement!.instructionTemplate).toContain('npm run test:e2e:mock');
+  });
+
+  it('should load e2e-test as a builtin piece in ja locale', () => {
+    languageState.value = 'ja';
+
+    const jaBuiltinNames = listBuiltinPieceNames({ includeDisabled: true });
+    expect(jaBuiltinNames).toContain('e2e-test');
+
+    const config = loadPiece('e2e-test', testDir);
+    expect(config).not.toBeNull();
+
+    const planMovement = config!.movements.find((movement) => movement.name === 'plan_test');
+    const implementMovement = config!.movements.find((movement) => movement.name === 'implement_test');
+
+    expect(planMovement).toBeDefined();
+    expect(implementMovement).toBeDefined();
+    expect(planMovement!.instructionTemplate).toContain('E2Eテスト');
+    expect(implementMovement!.instructionTemplate).toContain('npm run test:e2e:mock');
+  });
 });
 
 describe('Piece Loader IT: project-local piece override', () => {

src/__tests__/piece-category-config.test.ts

@@ -9,8 +9,12 @@ import { tmpdir } from 'node:os';
 import { randomUUID } from 'node:crypto';
 import type { PieceWithSource } from '../infra/config/index.js';
 
+const languageState = vi.hoisted(() => ({
+  value: 'en' as 'en' | 'ja',
+}));
+
 const pathsState = vi.hoisted(() => ({
-  resourcesDir: '',
+  resourcesRoot: '',
   userCategoriesPath: '',
 }));
 
@@ -18,7 +22,7 @@ vi.mock('../infra/config/global/globalConfig.js', async (importOriginal) => {
   const original = await importOriginal() as Record<string, unknown>;
   return {
     ...original,
-    getLanguage: () => 'en',
+    getLanguage: () => languageState.value,
     getBuiltinPiecesEnabled: () => true,
     getDisabledBuiltins: () => [],
   };
@@ -28,7 +32,7 @@ vi.mock('../infra/resources/index.js', async (importOriginal) => {
   const original = await importOriginal() as Record<string, unknown>;
   return {
     ...original,
-    getLanguageResourcesDir: () => pathsState.resourcesDir,
+    getLanguageResourcesDir: (lang: string) => join(pathsState.resourcesRoot, lang),
   };
 });
 
@@ -74,10 +78,12 @@ describe('piece category config loading', () => {
 
   beforeEach(() => {
     testDir = join(tmpdir(), `takt-cat-config-${randomUUID()}`);
-    resourcesDir = join(testDir, 'resources');
+    resourcesDir = join(testDir, 'resources', 'en');
 
     mkdirSync(resourcesDir, { recursive: true });
-    pathsState.resourcesDir = resourcesDir;
+    mkdirSync(join(testDir, 'resources', 'ja'), { recursive: true });
+    pathsState.resourcesRoot = join(testDir, 'resources');
+    languageState.value = 'en';
     pathsState.userCategoriesPath = join(testDir, 'user-piece-categories.yaml');
   });
 
@@ -142,6 +148,7 @@ piece_categories:
   Review:
     pieces:
       - review-only
+      - e2e-test
 show_others_category: true
 others_category_name: Others
 `);
@@ -168,7 +175,7 @@ others_category_name: Unclassified
           { name: 'Child', pieces: ['nested'], children: [] },
         ],
       },
-      { name: 'Review', pieces: ['review-only'], children: [] },
+      { name: 'Review', pieces: ['review-only', 'e2e-test'], children: [] },
       { name: 'My Team', pieces: ['team-flow'], children: [] },
     ]);
     expect(config!.builtinPieceCategories).toEqual([
@@ -179,7 +186,7 @@ others_category_name: Unclassified
           { name: 'Child', pieces: ['nested'], children: [] },
         ],
       },
-      { name: 'Review', pieces: ['review-only'], children: [] },
+      { name: 'Review', pieces: ['review-only', 'e2e-test'], children: [] },
     ]);
     expect(config!.userPieceCategories).toEqual([
       { name: 'Main', pieces: ['custom'], children: [] },
@@ -189,6 +196,24 @@ others_category_name: Unclassified
     expect(config!.othersCategoryName).toBe('Unclassified');
   });
 
+  it('should load ja builtin categories and include e2e-test under レビュー', () => {
+    languageState.value = 'ja';
+
+    writeYaml(join(testDir, 'resources', 'ja', 'piece-categories.yaml'), `
+piece_categories:
+  レビュー:
+    pieces:
+      - review-only
+      - e2e-test
+`);
+
+    const config = getPieceCategories();
+    expect(config).not.toBeNull();
+    expect(config!.pieceCategories).toEqual([
+      { name: 'レビュー', pieces: ['review-only', 'e2e-test'], children: [] },
+    ]);
+  });
+
   it('should override others settings without replacing categories when user overlay has no piece_categories', () => {
     writeYaml(join(resourcesDir, 'piece-categories.yaml'), `
 piece_categories: