JavaScript / TypeScript Coverage
Framework Configuration
Any JavaScript / TypeScript test framework that can generate LCOV reports is supported. While we provide examples for Jest and Vitest below, you can use any framework of your choice (Mocha, AVA, Jasmine, etc.) as long as it generates coverage reports in LCOV format.
Key Requirements
- Coverage report must be in LCOV format
- Report must be saved as
coverage/lcov.info - Report must be uploaded as a GitHub Actions artifact named
coverage-report
Jest
{
"scripts": {
"test": "jest"
}
}/** @type {import('jest').Config} */
module.exports = {
collectCoverage: true,
coverageReporters: ["lcov"],
collectCoverageFrom: [
"**/*.{js,jsx,ts,tsx}",
"!**/*.d.ts",
"!**/node_modules/**"
]
}Vitest
{
"scripts": {
"test": "vitest run --coverage"
}
}/// <reference types="vitest" />
import { defineConfig } from 'vite'
// https://vitest.dev/guide/coverage.html#coverage-setup
export default defineConfig({
test: {
coverage: {
provider: 'v8',
reporter: ['lcov'],
},
},
})Setting Up GitHub Actions
Create a workflow file in .github/workflows/ directory. The filename can be anything you prefer (e.g. coverage.yml). Add the following content to your workflow file:
name: Test Coverage
# Run on target branch (probably default branch like main) to track coverage history
on:
push:
branches:
- main
# Optional: Only run when relevant files change (customize as needed)
paths:
- '**/*.js'
- '**/*.ts'
- package.json
- package-lock.json
pull_request:
branches:
- main
paths:
- '**/*.js'
- '**/*.ts'
- package.json
- package-lock.json
- '!.github/workflows/**'
workflow_dispatch:
# Auto-cancel outdated runs on the same branch
concurrency:
group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
cancel-in-progress: true
jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v6
- name: Setup Node.js
uses: actions/setup-node@v6
with:
node-version: "22"
- name: Install dependencies
run: npm ci
# PR: tests only, Push: tests with coverage
- name: Run tests
if: github.event_name == 'pull_request'
run: npm test
- name: Run tests with coverage
if: github.event_name == 'push'
run: npm test -- --coverage
- name: Upload coverage report
if: github.event_name == 'push'
uses: actions/upload-artifact@v6
with:
name: coverage-report
path: coverage/lcov.infoKey Configuration Points
- Configure your test framework to generate LCOV reports
- Upload the report as an artifact - name must be either
coverage-reportor end withlcov.info - Ensure the artifact contains
coverage/lcov.infofile
Why !.github/workflows/** on PRs Only?
On pull requests, we exclude workflow file changes to keep the setup PR minimal. When you're adding or editing a workflow file, pre-existing test failures in your codebase are irrelevant and shouldn't block the PR. On push(after merge to main), we don't exclude them so that the initial coverage report gets generated on your target branch.
Viewing Coverage Reports
After your workflow runs successfully, GitAuto automatically processes the coverage reports and displays them in the Coverage Dashboard. GitAuto only saves coverage data when the workflow runs on your target branch (configurable in your repository's Rules page, defaults to your repository's default branch, e.g., main or master). This typically happens when:
- You merge a pull request to your target branch
- You push directly to your target branch
- You manually trigger the workflow
About LCOV:LCOV (Linux Code Coverage) is a standard format for code coverage data. It's pronounced "el-cov" and is widely supported by various tools and services.
Using multiple languages? If your repository has multiple programming languages (the docs use PHP + JavaScript as an example, but any combination works), see our Multi-Language Coverage guide for setting up coverage across all languages.
Jest Acting Up Again?
JavaScript testing can be a maze of configurations! Whether Jest is being stubborn, Vitest is throwing mysterious errors, or your GitHub Actions are failing silently, we've probably seen it before.
Contact us and let's solve this JavaScript puzzle!