@magic/test

Declaratively test your ecmascript module files. No transpiling of either your codebase nor the tests. Incredibly fast.

Getting Started

See the Getting Started guide for full instructions.

npm i --save-dev --save-exact @magic/test

// test/yourFileToTest.jsexport default [  { fn: () => true, expect: true, info: 'true is true' },]

Features

• Write tests in plain JavaScript or TypeScript
• Utility functions for deep equality, mocking, HTTP, and more
• Svelte 5 component testing built-in
• CLI tools with sharding for parallel test execution
• Test isolation for preventing state leakage
• Error codes for programmatic error handling

Quick Examples

Simple test

export default [  { fn: () => 1 + 1, expect: 2 },  { fn: () => 'hello', expect: 'hello']

Async test

import { promise } from '@magic/test'export default [  {    fn: promise(cb => setTimeout(() => cb(null, true), 100)),    expect: true,    info: 'handle promises',  },]

Deep equality

import { is } from '@magic/test'export default [  {    fn: () => ({ a: 1, b: 2 }),    expect: is.deep.equal({ a: 1, b: 2 }),    info: 'deep compare objects',  },]

Mock function

import { mock } from '@magic/test'export default [  {    fn: () => {      const spy = mock.fn()      spy('arg1')      return spy.calls.length === 1    },    expect: true,    info: 'mock tracks calls',  },]

Learn More

• Getting Started - install, setup, first test
• Writing Tests - hooks, promises, types, multiple tests
• Utility Functions - deep, fs, curry, log, vals, env, http, mock, has
• Svelte Testing - mount components, interact, assert
• Svelte 4 vs 5 - feature comparison
• Svelte Auto-Export FAQ - $state and $derived exports
• CLI & Usage - flags, sharding, performance tips
• CLI Flags Reference - detailed flag table
• CLI Sharding Cheat-Sheet - CI/CD examples
• Performance Tips - optimization techniques
• Common Pitfalls - troubleshooting tips
• Test Isolation - prevent state leakage between tests
• Error Codes - programmatic error handling
• Error Codes Quick Look - quick reference table
• - detailed release history

This library tests itself. Have a look at the tests on GitHub.