Setup coverage reporting and CI gates (enforce 90-92% line coverage)

[johnproblems]

Task: Setup coverage reporting and CI gates (enforce 90-92% line coverage)

Description

Configure comprehensive code coverage reporting using nyc/Istanbul and set up CI/CD pipeline gates to enforce minimum coverage thresholds. Integrate coverage reporting with GitHub Actions and add badges to the project README.

Acceptance Criteria

• nyc/Istanbul configured with 90-92% coverage thresholds
• Coverage reports generated in multiple formats (HTML, LCOV, JSON, text)
• CI pipeline fails if coverage drops below 90%
• Coverage reports uploaded to Codecov or Coveralls
• Coverage badge added to README
• Per-file coverage metrics visible
• Branch coverage and function coverage tracked
• Coverage trends monitored over time

Technical Details

• Configure .nycrc or nyc in package.json:

  {
    "all": true,
    "check-coverage": true,
    "lines": 90,
    "functions": 90,
    "branches": 90,
    "statements": 90,
    "reporter": ["html", "lcov", "text", "json"],
    "exclude": ["test/**", "out/**", "dist/**", "**/*.d.ts"]
  }

• Update package.json scripts:
  • test:coverage - run tests with coverage
  • coverage:report - generate HTML report
  • coverage:check - validate thresholds
• Configure GitHub Actions workflow:
  • Run tests with coverage on all PRs
  • Upload coverage reports to Codecov/Coveralls
  • Add PR comments with coverage diff
  • Fail builds below threshold
• Add coverage badge to README:
  • Codecov badge or Coveralls badge
  • Link to coverage dashboard
• Configure IDE coverage highlighting
• Files affected:
  • .nycrc or package.json (nyc config)
  • .github/workflows/test.yml (CI config)
  • README.md (badge)

Dependencies

• Task 3 - Testing infrastructure configured
• Task 52 - Frontmatter parser tests completed
• Task 53 - Data provider tests completed
• Task 54 - Status bar tests completed
• Task 55 - Command tests completed
• Task 56 - TreeDataProvider tests completed
• Task 57 - Progress panel tests completed
• Task 58 - File watcher tests completed
• Task 59 - GitHub API tests completed
• Task 60 - E2E tests completed

Effort Estimate

• Size: M
• Hours: 6
• Parallel: false

Definition of Done

• Code implemented
• Tests written and passing
• Documentation updated
• Code reviewed
• Coverage thresholds enforced in CI
• Coverage reports accessible
• Badge displayed in README
• All coverage targets met (90-92%)