# Atdd

> [UDS] Reference for Acceptance Test-Driven Development: INVEST criteria, Gherkin AC format, and Three Amigos structure. Use when: defining acceptance criteria with a product owner, running a specification workshop, checking a user story against INVEST. Not for: executing the ATDD lifecycle or enforcing PO sign-off gates — that moved to the adoption layer (XSPEC-095); writing unit tests — use /tdd. Keywords: ATDD, acceptance test, acceptance criteria, INVEST, specification workshop, Three Amigos, 驗收測試驅動開發, 驗收條件, 規格工作坊.

- Skill: `asiaostrich/atdd` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add asiaostrich/atdd`
- Raw SKILL.md: https://api.skillmd.com/api/skills/asiaostrich/atdd/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: AsiaOstrich (https://skillmd.com/u/asiaostrich)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/asiaostrich/atdd

---

<!-- DEPRECATION NOTICE (XSPEC-086 Phase 4, 2026-04-28):
  ATDD lifecycle orchestration (5-phase: WORKSHOP→DISTILLATION→DEVELOPMENT→DEMO→DONE,
  INVEST validation, AC→Gherkin conversion, RED/GREEN execution, PO sign-off gates) relocated to
  adoption layer (XSPEC-095, 2026-04-28). This Skill retains: INVEST criteria table, ATDD cycle
  diagram, Gherkin AC format, Three Amigos structure.
  For enforced lifecycle execution, use your adoption layer's toolchain.
-->

# ATDD Assistant | ATDD 助手

> ⚠️ **Status: Reference（參考用，非可執行流程）** — 5 階段 ATDD 生命週期協調（WORKSHOP→DISTILLATION→DEVELOPMENT→DEMO→DONE、INVEST 驗證、AC→Gherkin 轉換、RED/GREEN 執行、PO sign-off gates）已於 2026-04-28 移至 **adoption layer（XSPEC-095）**。此處保留 INVEST 準則、ATDD 循環圖、Gherkin AC 格式、Three Amigos 結構供參考。
> Lifecycle orchestration has moved to the adoption layer (XSPEC-095); this document is **reference-only**. For enforced execution, use your adoption layer's toolchain.

Guide through the Acceptance Test-Driven Development (ATDD) workflow for defining and validating user stories.

引導驗收測試驅動開發（ATDD）流程，用於定義和驗證使用者故事。

## ATDD Cycle | ATDD 循環

```
WORKSHOP ──► DISTILLATION ──► DEVELOPMENT ──► DEMO ──► DONE
    ^                              │              │
    └──────────────────────────────┴──────────────┘
                  (Refinement needed)
```

## Workflow | 工作流程

> 📖 以下為流程的**參考結構**，非可執行步驟；自動化／強制執行請用 adoption layer 工具鏈（XSPEC-095）。
> The steps below are a **reference structure**, not an executable workflow.

### 1. WORKSHOP - Define AC | 定義驗收條件
PO presents user story, team asks clarifying questions, define acceptance criteria together.

### 2. DISTILLATION - Convert to Tests | 轉換為測試
Convert AC to executable test format, remove ambiguity, get PO sign-off.

### 3. DEVELOPMENT - Implement | 實作
Run acceptance tests (should fail initially), use BDD/TDD for implementation, iterate until all pass.

### 4. DEMO - Present | 向利害關係人展示
Show passing acceptance tests, demonstrate working functionality, get formal acceptance.

### 5. DONE - Complete | 完成
PO accepted, code merged, story closed.

## INVEST Criteria | INVEST 準則

| Criterion | Description | 說明 |
|-----------|-------------|------|
| **I**ndependent | Can be developed separately | 可獨立開發 |
| **N**egotiable | Details can be discussed | 可協商細節 |
| **V**aluable | Delivers business value | 提供商業價值 |
| **E**stimable | Can estimate effort | 可估算工作量 |
| **S**mall | Fits in one sprint | 一個 Sprint 可完成 |
| **T**estable | Has clear acceptance criteria | 有明確驗收條件 |

## User Story Format | 使用者故事格式

```markdown
As a [role],
I want [feature],
So that [benefit].

### Acceptance Criteria
- Given [context], when [action], then [result]
```

## Usage | 使用方式

```
/atdd                              - Start interactive ATDD session | 啟動互動式 ATDD 會話
/atdd "user can reset password"    - ATDD for specific feature | 針對特定功能
/atdd US-123                       - ATDD for existing user story | 處理現有使用者故事
```

## Next Steps Guidance | 下一步引導

After `/atdd` completes, the AI assistant should suggest:

> **驗收測試已定義。建議下一步 / Acceptance tests defined. Suggested next steps:**
> - 執行 `/sdd` 建立規格文件 ⭐ **Recommended / 推薦** — Create a specification document
> - 執行 `/bdd` 將 AC 轉為 Gherkin 場景 — Convert AC to Gherkin scenarios
> - 執行 `/tdd` 直接實作驗收測試 — Implement acceptance tests directly

## Reference | 參考

- [Acceptance Criteria Writing Guide](./acceptance-criteria-guide.md) — Read it when writing or reviewing acceptance criteria.
- [ATDD Workflow Guide](./atdd-workflow.md) — Read it when running the ATDD cycle end to end.
- Detailed guide: [guide.md](./guide.md)
- Core standard: [acceptance-test-driven-development.md](../../core/acceptance-test-driven-development.md)


## AI Agent Behavior | AI 代理行為

> 完整的 AI 行為定義請參閱對應的命令文件：[`/atdd`](../commands/atdd.md#ai-agent-behavior--ai-代理行為)
>
> For complete AI agent behavior definition, see the corresponding command file: [`/atdd`](../commands/atdd.md#ai-agent-behavior--ai-代理行為)