@kitest/kitest NPM

kitest is a fast, minimalist test runner for TypeScript and JavaScript, with a small, easy-to-learn API that lets you focus on your tests — not your tooling.

Fast, minimal, precise, safe, atomic, and easy to use.

Features

🚀 Fast & Reliable

Multi-process parallel test runner. Each test file is run in its own process/runtime for performance and isolation benefits. Use on a multicore machine for best results.
Optimized for speed and simplicity.
Minimal dependencies.

😀 Easy to Use

Very simple functional assertion API. No need to learn a DSL or framework.
Built-in powerful diff visualization tool and clean, organized output.
Failed tests are easy to find, grouped at the end of the output.
Errors or unhandled promise rejections are buffered and grouped under the test file in the output. This helps you know where they came from.
Clean stack traces with no extra noise.

🛡 Defensive

Uncaught errors and unhandled promise rejections will cause the test to fail.
Any spec files without tests, or tests without assertions, result in a failed test.
Strict and deep equality comparison by default.

🔒 Out-of-the-box Typescript support

No special configuration needed, and no plugins to install.
Works great with c8 for code coverage.
Handles compilation errors gracefully.

Quick Examples

import {test} from '@kitest/kitest';

// Basic test

function greet(name: string): string {
  return `hello, ${name}`;
}

test('greet()', (assert) => {
  assert.equal(hello('world'), 'hello, world');
});

// Error handling

function throwError(): never {
  throw new Error('oops');
}

test('throwError()', (assert) => {
  assert.throws(() => throwError(), /oops/);
});

// Async test

async function fetchData(): Promise<string> {
  return Promise.resolve('data');
}

test('fetchData()', async (assert) => {
  const data = await fetchData();
  assert.equal(data, 'data');
});

Getting Started

To install and get started with kitest, see our Getting Started guide.

Examples

See the examples and src folders for more examples.

Support, feedback, and contributions

Star this repo if you like it!
Submit an issue with your problem, feature request or bug report
Issue a PR against main and request review. Make sure all tests pass and coverage is good.
Write about this project in your blog, tweet about it, or share it with your friends!

Sponsorship

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Want to sponsor this project? Reach out.

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