AgentSkillsCN

Test Writer

专精代理，通过分类批量修复与模式识别，系统性提升测试覆盖率，从当前基线提升至≥80%。在为业务逻辑编写单元测试、为跨边界操作编写集成测试、为关键用户旅程执行端到端测试，或通过战略性测试优先级排序达成≥80%的测试覆盖率目标时，可运用此技能。

SKILL.md
--- frontmatter
name: Test Writer
description: Specialized agent for systematic improvement of test coverage from current baseline to ≥80%. Use this skill when writing unit tests for business logic, integration tests for cross-boundary operations, E2E tests for critical user journeys, or achieving ≥80% test coverage target with strategic test prioritization.

Test Writer

This Skill provides Claude Code with specific guidance for improving test coverage systematically.

When to use this skill

  • •When test coverage is below 80% (current: 16.6%)
  • •When writing unit tests for business logic (fast, isolated)
  • •When writing integration tests for cross-boundary operations
  • •When writing E2E tests for critical user journeys (Playwright)
  • •When prioritizing testing by risk (P0: data loss, P1: user-facing)
  • •When mocking external dependencies (WebContainer, AI providers)
  • •When testing edge cases and error states

Instructions

For detailed implementation guidance, refer to: Test Writer Agent

Workflow Integration

This skill follows the testing-test-writing workflow:

  1. •Coverage Analysis: Identify untested critical paths, calculate coverage metrics, prioritize by risk
  2. •Test Writing: Write unit tests for business logic, integration tests for boundaries, E2E tests for critical journeys
  3. •Test Quality: Follow best practices (AAA pattern, descriptive names), mock external dependencies, test edge cases
  4. •Validation: Run test suite (100% pass rate), measure coverage, ensure no regression

Quality Standards

Test Coverage Target

  • •✅ Target: ≥80% coverage (current: 16.6%)
  • •✅ Unit Tests: Business logic, utilities, pure functions
  • •✅ Integration Tests: Store + component interactions
  • •✅ E2E Tests: Critical user journeys (login, file operations, AI chat)

Test Quality

  • •✅ AAA pattern (Arrange, Act, Assert)
  • •✅ Descriptive test names (should [expected behavior] when [state/context])
  • •✅ Mock external dependencies (WebContainer, AI providers)
  • •✅ Test edge cases and error states
  • •✅ Tests are maintainable and reliable

Test Prioritization Strategy

P0: Critical Paths (Data Loss Risk)

  • •File system operations (read, write, delete)
  • •Database operations (IndexedDB CRUD)
  • •Authentication and authorization
  • •State persistence and hydration

P1: User-Facing Features

  • •UI components (critical workflows)
  • •AI agent interactions
  • •Workspace switching
  • •Sync operations

P2: Business Logic

  • •Data transformations
  • •Validation logic
  • •Error handling
  • •Utility functions

Example Usage

code
"Write tests for src/lib/state/rag-store.ts to achieve ≥80% coverage"

This will:

  1. •Analyze current coverage for the store
  2. •Identify untested critical paths (CRUD operations, state updates)
  3. •Write unit tests for each action method
  4. •Write integration tests for store + component interactions
  5. •Validate with coverage measurement

Validation Commands

bash
# Run test suite
pnpm test

# Measure coverage
pnpm test -- --coverage

# Check coverage report
open coverage/index.html

# Show uncovered lines
pnpm test -- --coverage --reporter=text-summary

Success Criteria

  • •✅ Test coverage ≥80% (target)
  • •✅ 100% test pass rate
  • •✅ All critical paths tested (P0 priority)
  • •✅ Edge cases and error states covered
  • •✅ Tests are maintainable (clear names, good structure)
  • •✅ External dependencies properly mocked