johnlindquist/claude/testgen

# Gemini for AI generation
pip install google-generativeai
export GEMINI_API_KEY=your_api_key
 
# Test runners (install as needed)
npm install -D jest vitest mocha
npm install -D @stryker-mutator/core  # Mutation testing

# Read code and generate tests
CODE=$(cat src/utils.ts)
 
gemini -m pro -o text -e "" "Generate comprehensive unit tests for this code:
 
$CODE
 
Requirements:
1. Use Jest/Vitest syntax
2. Cover happy path, edge cases, and error conditions
3. Include descriptive test names
4. Mock external dependencies
5. Test each exported function
 
Output only the test code, ready to save to a file."

gemini -m pro -o text -e "" "Generate unit tests for this function:
 
\`\`\`typescript
export function calculateDiscount(price: number, percentage: number): number {
  if (percentage < 0 || percentage > 100) {
    throw new Error('Invalid percentage');
  }
  return price * (1 - percentage / 100);
}
\`\`\`
 
Include tests for:
- Valid inputs
- Boundary values (0%, 100%)
- Invalid inputs (negative, >100)
- Edge cases (zero price)
 
Use Jest syntax."

# 1. Write failing test first
gemini -m pro -o text -e "" "Write a failing test for: [feature description]"
 
# 2. Run test (should fail)
npm test -- --watch
 
# 3. Implement minimal code to pass
 
# 4. Refactor
 
# 5. Repeat

# Run all tests
npx jest
 
# Watch mode
npx jest --watch
 
# Specific file
npx jest src/utils.test.ts
 
# With coverage
npx jest --coverage
 
# Update snapshots
npx jest -u
 
# Verbose output
npx jest --verbose
 
# Run matching pattern
npx jest -t "should calculate"

# Run tests
npx vitest
 
# Watch mode
npx vitest --watch
 
# Run once
npx vitest run
 
# Coverage
npx vitest --coverage
 
# UI mode
npx vitest --ui
 
# Specific file
npx vitest src/utils.test.ts

# Run tests
npx mocha
 
# Watch mode
npx mocha --watch
 
# Specific file
npx mocha test/utils.test.js
 
# With reporter
npx mocha --reporter spec

# Jest
npx jest --coverage --coverageReporters=text --coverageReporters=html
 
# Vitest
npx vitest run --coverage
 
# View HTML report
open coverage/index.html

// jest.config.js or vitest.config.ts
{
  "coverageThreshold": {
    "global": {
      "branches": 80,
      "functions": 80,
      "lines": 80,
      "statements": 80
    }
  }
}

# Text coverage report
npx jest --coverage --coverageReporters=text
 
# Ask AI for suggestions
UNCOVERED=$(npx jest --coverage --coverageReporters=json --silent | jq '.coverageMap')
gemini -m pro -o text -e "" "Given this coverage report, suggest tests for uncovered code:
 
$UNCOVERED"

# Check if installed
npx stryker --version
 
# Initialize
npx stryker init
 
# Run mutation testing
npx stryker run
 
# With reporters
npx stryker run --reporters clear-text,json,html

# 1. Generate test scaffold
CODE=$(cat src/new-feature.ts)
gemini -m pro -o text -e "" "Generate test file scaffold for: $CODE" > src/new-feature.test.ts
 
# 2. Run tests (should fail)
npx jest src/new-feature.test.ts
 
# 3. Implement feature
# 4. Run tests (should pass)
# 5. Add edge case tests
# 6. Check coverage
npx jest src/new-feature.test.ts --coverage

# After fixing a bug, generate regression test
BUG_DESC="Users could submit empty forms"
FIX=$(git diff HEAD~1)
 
gemini -m pro -o text -e "" "Generate a regression test for this bug fix:
 
Bug: $BUG_DESC
 
Fix:
$FIX
 
The test should fail if the bug is reintroduced."

gemini -m pro -o text -e "" "Generate integration tests for this API endpoint:
 
\`\`\`typescript
// POST /api/users
// Body: { name: string, email: string }
// Response: { id: string, name: string, email: string }
\`\`\`
 
Include:
- Success case
- Validation errors
- Duplicate email handling
- Authentication required
 
Use supertest or similar."