🥛 Latte

Latte (an abbreviation from laconic testing) is a testing framework designed for testing applications written in JavaScript and TypeScript.

It is designed to be straightforward to use, with a focus on speed, performance, and user information.

Latte is an alternative to other testing frameworks like Jest, Mocha, and Jasmine with the following core features:

• Config free.
• Functions for creating test cases it, test, describe, suite or expect.
• Setup and Teardown functions beforeEach, afterEach, beforeAll, afterAll.
• React Components testing (jsx syntax supported).
• HTML Components testing (DOM built-in).
• Headless browser in scope B for test web pages and remote saites.
• Asynchronous code testing with async/await.
• Mock functions.
• Big set (100+) of built-in matchers.
• TypeScript testing out of the box. You can use both js and ts test files in the same project.
• Simple extend Expect class for adding your matchers.
• A lot of expects in one test case.
• Built-in coverage tool.
• Verbose, Watching and Debug mode.
• Different Reporters: lcov, console, html, and junit.
• Open source and MIT license.

Quick Reference

Installation

npm install @olton/latte -D

Usage

IntelliJ plugin

You can use Latte with IntelliJ IDEA, WebStorm, PhpStorm, and other JetBrains IDEs. The plugin is available in the JetBrains Marketplace.

Command line

Create a test file with *.test.js or *.test.ts extension (for example). You can use both of them in the same project.

function hello() {
    return "Hello"
}

describe(`Common tests suite`, () => {
    it(`says hello`, () => {
        return expect(hello()).toBe("Hello")
    })
})

test(`Bad test 2 !== 1`, () => {
    return expect(2).toBe(1)
})

Update package.json to run tests with latte command.

{
    "scripts": {
        "test": "latte"
    }
}

Run tests

Now you can run tests with the following command:

npm test

or with npx:

npx latte

Functions

• describe – create a test suite
• it - create a test case in suite
• test - create standalone test
• expect - create assertion
• beforeEach - run before each test case
• afterEach - run after each test case
• beforeAll - run before all test cases
• afterAll - run after all test cases
• mock - create mock function

Matchers

Latte contains a big set of built-in matchers:

• A simple comparison
• A strong comparison
• Type checking
• Number checking
• String checking
• Array checking
• Object checking
• Color checking
• IP, Email, Url checking
• JSON, XML checking
• Date, RegExp, Symbol checking
• Function checking
• HTML element checking
• and more...

TypeScript

To use Latte with TypeScript you need to install tsx package.

npm install -D tsx cross-env

and then

{
    "scripts": {
        "test": "cross-env NODE_OPTIONS=\"--import tsx\" latte"
    }
}

License

Latte licensed under MIT license.

Contributing

Bug Reports & Feature Requests

Use issue tracker to report bugs or request new features.

Code Standards

Support

If you like this project, please consider supporting it by:

• Star this repository on GitHub
• Sponsor this project on GitHub Sponsors
• PayPal to [email protected].
• Patreon
• Buy me a coffee

Copyright (c) 2025 by Serhii Pimenov