Comprehensive Codecov integration with 2025 features

[RAprogramm]

Objective

Implement comprehensive Codecov integration with all modern features available in 2025 for full coverage visibility and automation.

Current State

• Basic coverage job exists in CI
• LCOV reports uploaded to Codecov
• Badge not displaying in README
• Token configured: OD4F7LWWB8
• Coverage artifacts stored for 30 days

Required Features

1. Badge Display Fix

• Add badge to README with token parameter for private repo
• Format: https://codecov.io/gh/RAprogramm/masterror/badge.svg?token=OD4F7LWWB8
• Ensure badge shows after first upload

2. PR Comments Integration

• Automatic coverage reports in PR comments
• Coverage diff showing changes vs base branch
• Line-by-line coverage annotations
• Failed coverage check warnings

3. Coverage Thresholds

• Set minimum coverage percentage (target: 95-100%)
• Fail CI if coverage drops below threshold
• Configure per-project and per-patch thresholds
• Allow minor fluctuations for new features

4. Coverage Trends

• Historical coverage tracking
• Visualization of coverage over time
• Sunburst charts for codebase coverage
• Icicle graphs for detailed analysis

5. Advanced Configuration

• codecov.yml configuration file
• Ignore paths (tests, examples, generated code)
• Coverage comparison settings
• Notification preferences

6. Status Checks

• GitHub status check integration
• Block merges below coverage threshold
• Carryforward flags for incremental uploads
• Multiple upload support (if needed)

Implementation Plan

1. Create codecov.yml configuration
2. Update README with proper badge
3. Configure PR comment integration
4. Set coverage thresholds (95% target)
5. Enable status checks
6. Test on PR to verify all features

Success Criteria

• Badge displays correctly in README
• PR comments show coverage diff
• Coverage thresholds enforced
• Status checks pass/fail appropriately
• Historical trends visible on Codecov dashboard
• All 2025 Codecov features utilized

Documentation

• Official docs: https://docs.codecov.com
• Badge docs: https://docs.codecov.com/docs/status-badges
• PR comments: https://docs.codecov.com/docs/pull-request-comments
• Configuration: https://docs.codecov.com/docs/codecov-yaml

[RAprogramm]

Status Update

✅ Already Implemented

1. Badge Display - Badge correctly displayed in README with token

   • Format: [![codecov](https://codecov.io/gh/RAprogramm/masterror/graph/badge.svg?token=OD4F7LWWB8)](https://codecov.io/gh/RAprogramm/masterror)
   • Present in both README.md and README.template.md

2. Coverage Upload - Configured in .github/workflows/reusable-ci.yml

   • Uses cargo-llvm-cov for LCOV generation
   • Uploads via codecov/codecov-action@v5 with OIDC
   • Runs on every CI build

3. Test Analytics - Fully configured

   • Uses cargo-nextest for JUnit XML generation
   • Uploads via codecov/test-results-action@v1
   • Profile: .config/nextest.toml with CI-specific settings

4. Configuration File - .github/codecov.yml (just fixed location)

   • Coverage thresholds: 95% target, 1% drop tolerance
   • Patch coverage: 95% for new code
   • Test Analytics enabled with flaky test detection
   • PR comment layout configured

🔄 Needs Verification

1. PR Comments - Configuration ready, needs PR to test

   • Settings in codecov.yml: condensed layout, auto-update behavior
   • Should show coverage diff and file-level changes

2. GitHub Status Checks - May need repository settings

   • Check if Codecov integration is enabled in GitHub repo settings
   • Verify status check appears on PRs

3. Coverage Trends - Should work automatically

   • Historical data accumulates with each upload
   • Visualizations available on Codecov dashboard

📝 Next Steps

1. Create a test PR to verify:

   • PR comment appears with coverage diff
   • Status checks show up
   • Test Analytics data appears

2. If PR comments don't appear:

   • Check Codecov GitHub App installation
   • Verify repository access in Codecov settings

3. If status checks don't appear:

   • Enable Codecov status checks in GitHub repo settings
   • Configure required checks for branch protection

All infrastructure is in place. Just needs a PR to confirm everything works end-to-end.