Contract Test Assistant | 合約測試助手

Language: English | 繁體中文

Guide contract testing strategy selection, setup, and verification for APIs and microservices.

引導 API 和微服務的合約測試策略選擇、設定和驗證。

What is Contract Testing? | 什麼是合約測試？

Contract testing verifies that services can communicate correctly by testing the agreements (contracts) between consumers and providers — without requiring all services to be running.

合約測試透過測試消費者和提供者之間的協議（合約）來驗證服務間的通訊正確性，不需要所有服務同時運行。

Strategy Selection | 策略選擇

Workflow | 工作流程

ASSESS ──► CHOOSE ──► DEFINE ──► IMPLEMENT ──► VERIFY
  評估架構    選擇策略    定義合約     實作測試      驗證合約

1. ASSESS — Evaluate Architecture | 評估架構

• How many services communicate?
• Who owns consumer vs provider?
• 有多少服務互相通訊？誰擁有消費者/提供者？

2. CHOOSE — Select Strategy | 選擇策略

• Consumer-Driven (Pact) vs Provider-Driven (OpenAPI)
• 消費者驅動 (Pact) vs 提供者驅動 (OpenAPI)

3. DEFINE — Create Contract | 定義合約

• Write consumer expectations or OpenAPI spec
• 撰寫消費者期望或 OpenAPI 規格

4. IMPLEMENT — Write Tests | 實作測試

• Consumer tests generate contracts
• Provider tests verify against contracts
• 消費者測試產生合約；提供者測試驗證合約

5. VERIFY — Run Verification | 驗證

• CI pipeline verifies contracts on every PR
• CI 管線在每個 PR 上驗證合約

Commands | 指令

Contract Coverage Report | 合約覆蓋率報告

## Contract Coverage Report

| Consumer | Provider | Endpoint | Status |
|----------|----------|----------|--------|
| web-app | user-api | GET /users/:id | ✅ Verified |
| web-app | user-api | POST /users | ✅ Verified |
| mobile-app | auth-api | POST /login | ⚠️ Consumer only |
| admin-ui | report-api | GET /reports | ❌ No contract |

**Coverage**: 50% (2/4 endpoints verified both sides)

Integration | 與其他技能的整合

Migration Contract Tests — When Replacing an Implementation | 遷移合約測試（替換實作時）

When migrating an API endpoint from one tech stack to another (PHP → .NET, Express → Spring, etc.), a contract test against a legacy reference fixture catches missing fields, renamed fields, and placement drift that unit tests on the new DTO cannot. See migration-assistant § API Migration Contract Tests for the fixture capture protocol and audit checklist.

當 API endpoint 從一個技術棧遷至另一個（PHP → .NET、Express → Spring 等），對 legacy 參考 fixture 的 contract test 可捕捉「缺漏欄位」「rename」「層級漂移」等新 DTO 單元測試無法覆蓋的缺陷。詳見 migration-assistant § API Migration Contract Tests。

Next Steps Guidance | 下一步引導

After /contract-test completes:

合約測試引導完成。建議下一步：

• 執行 /ci-cd 將合約驗證加入 CI 管線
• 執行 /api-design 完善 API 設計
• 執行 /testing 整合到整體測試策略

Reference | 參考

• Detailed guide: guide.md — contract testing strategy and setup. Read it when configuring Pact/OpenAPI or wiring contract tests into CI.
• Detailed guide: contract-testing.md
• Related: api-design-assistant

AI Agent Behavior | AI 代理行為

When /contract-test is invoked:

1. Assess — Ask about architecture (monolith, microservices, number of APIs)
2. Recommend — Suggest strategy based on architecture
3. Guide — Walk through setup for chosen strategy
4. Generate — Create example contract test files
5. Verify — If verify subcommand, scan for contracts and report coverage