Jest Coverage Reporter

A modern, TypeScript-based GitHub Action that compares code coverage reports between branches and provides detailed feedback in pull requests.

Screenshots

Success Screenshot

Failure Screenshot

Features

• Compare code coverage between base and current branches
• Detect decreased coverage in changed files
• Require 100% coverage for newly added files
• Support for Jest and Cobertura coverage reports
• Detailed GitHub PR comments with coverage changes
• Configurable thresholds and options

Usage

- name: Coverage Report
  uses: adRise/jest-cov-reporter@main
  with:
    branch-coverage-report-path: ./coverage/coverage-summary.json
    base-coverage-report-path: ./coverage/master-coverage-summary.json
    delta: 0.3
    accessToken: ${{ secrets.GITHUB_TOKEN }}
    fullCoverageDiff: true
    useSameComment: true

Options

Option	Description	Default
base-coverage-report-path	Path to base coverage report	Required
branch-coverage-report-path	Path to the current coverage report	Required
accessToken	Access token required to comment on a PR	${{ github.token }}
fullCoverageDiff	Get the full coverage with diff or only the diff	false
delta	Difference threshold between the old and final test coverage	0.2
useSameComment	Update existing comment on the PR instead of creating new ones	true
custom-message	Pass any custom string which will be displayed in the comment	''
only-check-changed-files	Only test for changed files in the PR	true
prefix-filename-url	Add a base URL to the filenames and make it a hyperlink	''
check-new-file-full-coverage	Check newly added files whether have full coverage tests	true
coverageType	Tools that generate code coverage, supports 'jest' and 'cobertura'	'jest'

Full Coverage for New Files

The check-new-file-full-coverage option enforces that all newly added files have 100% test coverage. This encourages developers to write comprehensive tests for new code.

You can add a label to your PR called skip-new-file-full-coverage to bypass this check for specific PRs.

Development

Prerequisites

• Node.js (v16+)
• npm or yarn

Setup

# Install dependencies
npm install

# Run tests
npm test

# Build the project
npm run build

Project Structure

/src
  /core            # Core functionality
    /diff          # Coverage diff calculation
    /threshold     # Coverage threshold validation
    /format        # Report formatting
  /parsers         # Coverage report parsers
  /utils           # Utility functions
  /types           # TypeScript types

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT