jest-config

What is jest-config?

The jest-config package is used for configuring Jest, a popular JavaScript testing framework. It allows developers to programmatically access and manipulate Jest's configuration settings, making it easier to set up and customize tests for JavaScript projects. This package is particularly useful for complex setups or when integrating Jest into larger, automated workflows.

What are jest-config's main functionalities?

Accessing Default Configuration

This feature allows developers to access Jest's default configuration settings. It's useful for understanding the baseline configuration and for extending or customizing these defaults in a project.

const { defaults } = require('jest-config');
console.log(defaults);

Generating a Custom Configuration

This feature enables the creation of a custom Jest configuration programmatically. It's particularly useful for dynamically generating configurations based on specific project requirements or environments.

const { makeConfig } = require('jest-config');
const customConfig = makeConfig({
  rootDir: process.cwd(),
  transform: {
    '^.+\\.js$': 'babel-jest'
  }
});
console.log(customConfig);

Other packages similar to jest-config

mocha

Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple. While Mocha itself is not a configuration tool, it offers a flexible API and a variety of command-line options for configuring tests, similar to how jest-config allows for Jest test configuration.

karma

Karma is a test runner for JavaScript that runs on Node.js. It is designed to work with any testing framework, such as Jasmine, Mocha, or QUnit. Karma itself is more about running tests in different environments rather than configuring a specific testing framework. However, it deals with the aspect of setting up testing environments, which can be seen as a parallel to configuring testing frameworks with jest-config.

ava

AVA is a test runner for Node.js with a concise API, detailed error output, and process isolation that lets you develop with confidence. AVA's configuration approach is more direct and less flexible compared to jest-config, focusing on simplicity and convention over configuration.

README

The README file is missing

Changelog

29.7.0

Features

• [create-jest] Add npm init / yarn create initialiser for Jest projects (#14465)
• [jest-validate] Allow deprecation warnings for unknown options (#14499)

Fixes

• [jest-resolver] Replace unmatched capture groups in moduleNameMapper with empty string instead of undefined (#14507)
• [jest-snapshot] Allow for strings as well as template literals in inline snapshots (#14465)
• [@jest/test-sequencer] Calculate test runtime if perStats.duration is missing (#14473)

Performance

• [@jest/create-cache-key-function] Cache access of NODE_ENV and BABEL_ENV (#14455)

Chore & Maintenance

• [jest-cli] Move internal config initialisation logic to the create-jest package (#14465)