What is this?
AVA is a test runner for Node.js: it runs your tests with a concise API, detailed error output and thread isolation, so you can develop with confidence.
AVA is a test runner for Node.js: it runs your tests with a concise API, detailed error output and thread isolation, so you can develop with confidence.Is it a library I import into my code, or a tool I run?A command-line tool: you install it into your project and it runs your test files through a test script in package.json (or directly with npx ava).
A command-line tool: you install it into your project and it runs your test files through a test script in package.json (or directly with npx ava).How do I get it running?Install it locally with npm or Yarn, configure the test script in package.json, create a test.js file in the project root, then run your tests with npx ava — add the --watch flag to rerun them as you edit.
Install it locally with npm or Yarn, configure the test script in package.json, create a test.js file in the project root, then run your tests with npx ava — add the --watch flag to rerun them as you edit.What do I need installed to use it?Just Node.js itself — AVA supports the latest release of any major version that Node.js supports (its engines field currently asks for ^22.20, ^24.12 or >=26).
Just Node.js itself — AVA supports the latest release of any major version that Node.js supports (its engines field currently asks for ^22.20, ^24.12 or >=26).Any install pitfalls?Yes — AVA cannot be run globally; it must be installed locally in each project. The documentation also assumes you're using ES modules, and there's a maintained list of common pitfalls.
Yes — AVA cannot be run globally; it must be installed locally in each project. The documentation also assumes you're using ES modules, and there's a maintained list of common pitfalls.Why pick AVA over other Node.js test runners?Tests run concurrently with an isolated environment for each test file, so they stay fast and atomic; it enforces no implicit globals, cleans unrelated lines out of stack traces, and automatically splits test files across parallel CI builds. A TAP reporter is included too.
Tests run concurrently with an isolated environment for each test file, so they stay fast and atomic; it enforces no implicit globals, cleans unrelated lines out of stack traces, and automatically splits test files across parallel CI builds. A TAP reporter is included too.What is the 'magic assert'?AVA's assertion output shows code excerpts and clean diffs between actual and expected values. For objects and arrays it displays only the diff, syntax-highlighted; for strings it highlights exactly which characters were added or are missing.
AVA's assertion output shows code excerpts and clean diffs between actual and expected values. For objects and arrays it displays only the diff, syntax-highlighted; for strings it highlights exactly which characters were added or are missing.Can I write my tests in TypeScript?Yes — TypeScript definitions are included out of the box, there's a TypeScript recipe in the docs, and the companion @ava/typescript package is made for testing TypeScript projects.
Yes — TypeScript definitions are included out of the box, there's a TypeScript recipe in the docs, and the companion @ava/typescript package is made for testing TypeScript projects.What can I test beyond plain unit tests?The recipes cover endpoint testing, browser testing with Puppeteer or Selenium, Vue.js components, isolated MongoDB integration tests, code coverage, and debugging tests with Chrome DevTools, VSCode or WebStorm.
The recipes cover endpoint testing, browser testing with Puppeteer or Selenium, Vue.js components, isolated MongoDB integration tests, code coverage, and debugging tests with Chrome DevTools, VSCode or WebStorm.Which topics is it in?test-framework, cli-app, tdd, test-automation, unit-testing, concurrency, async, node, ci, testing, performance, command-line-tool
test-framework, cli-app, tdd, test-automation, unit-testing, concurrency, async, node, ci, testing, performance, command-line-tool