Daily Test Coverage Improver - Fix coverage steps configuration for CI environment

[github-actions]

Problem

The coverage steps configuration in .github/actions/daily-test-improver/coverage-steps/action.yml is failing in CI with two critical issues:

1. Node.js version mismatch: Vite 7.x requires Node.js 20.19+ or 22.12+, but the action was configured for Node.js 18
2. DNS resolution failure: Tests fail with Error: getaddrinfo EAI_AGAIN localhost due to missing /etc/hosts file in some CI environments

From coverage-steps.log:

You are using Node.js 18.20.8. Vite requires Node.js version 20.19+ or 22.12+
⎯⎯⎯⎯⎯ Startup Error ⎯⎯⎯⎯⎯
Error: getaddrinfo EAI_AGAIN localhost

Solution

This PR updates the coverage steps action to:

1. Upgrade Node.js to v20

• Changed node-version: '18' to node-version: '20' to meet Vite requirements
• Eliminates deprecation warnings during build

2. Add hosts file setup step

• Creates /etc/hosts if missing in CI environment
• Maps 127.0.0.1 and ::1 to localhost
• Prevents DNS resolution errors during test execution

3. Switch to happy-dom environment

• Changed Vitest environment from jsdom to happy-dom
• happy-dom is lighter weight and more compatible with containerized CI environments
• Handles DOM testing without requiring full browser infrastructure
• Added happy-dom to installed npm dependencies

Testing Needed

This PR should be tested in the actual GitHub Actions CI environment to verify:

• /etc/hosts setup step completes successfully (may need sudo permissions)
• JavaScript/TypeScript tests run without DNS errors
• Coverage reports are generated in coverage/js/
• Python tests continue to work as expected

Reproducibility

To test coverage generation after these changes:

# Install dependencies
npm install

# Run coverage
npm run test:coverage

# Check coverage report
ls -la coverage/js/

Alternative Approaches Considered

If the hosts file setup fails due to permission issues:

1. Use IP address directly: Configure Vitest to use 127.0.0.1 instead of localhost
2. Environment variable: Set HOST=0.0.0.0 before running tests
3. Container network mode: Use --network=host in Docker-based CI

Impact

• Enables coverage steps to complete successfully
• Unblocks Phase 3 test coverage improvement work
• No changes to repository code, only CI configuration

AI generated by Daily Test Coverage Improver