setup Archives | JS FAQ - JavaScript Guides Online

How to use beforeEach and afterEach in Jest

Common afterEach pitfalls include not handling asynchronous operations properly, failing to reset global state, leaving event listeners active, and misusing afterEach for assertions or mock resets. Proper use ensures clean test environments, isolated tests, and reliable, maintainable test suites.

Bundlers: Webpack/Rollup

How to create a basic Webpack config file

Bundlers: Webpack/Rollupconfig, minimal, setup, webpack

The Webpack configuration file, webpack.config.js, is crucial for project building. Key components include entry points, output settings, module rules, and resolve configurations. Additional features like devtool for source maps and devServer for live reloading enhance development. Optimization strategies improve performance, while environment variables manage configurations.

Libraries: Three.js

How to create a camera in Three.js

Libraries: Three.jscamera, perspective, setup, three.js

Camera field of view (FOV) controls scene visibility and depth perception in 3D environments. Adjusting FOV and aspect ratio is key for consistent visuals across screens. Updating camera.fov and camera.aspect with updateProjectionMatrix() ensures correct rendering and responsiveness during window resizing.

Transpilers: Babel

How to install Babel in a JavaScript project

Transpilers: Babelbabel, install, npm, setup

Configuring Babel for diverse environments optimizes builds for development, testing, and production. Tailor settings using the env option in your Babel config, and utilize @babel/preset-env to specify target browsers or Node.js versions. Implement efficient polyfilling strategies with core-js and manage plugins for distinct environments, ensuring streamlined performance and compatibility.

Libraries: TensorFlow.js

How to install TensorFlow.js in a project

Libraries: TensorFlow.jsinstall, script, setup, tensorflowjs

TensorFlow.js installation verification includes checking the tf object in the console, running basic tensor operations, and confirming version compatibility. For Node.js, import @tensorflow/tfjs-node and test tensors. Verify GPU support by checking WebGL availability via tf.ENV.get('WEBGL_VERSION').

E2E Testing: Cypress

How to install and set up Cypress

E2E Testing: Cypressconfig, cypress, install, setup

Cypress configuration using cypress.config.js for e2e tests. Set baseUrl, specPattern, and env variables. Use setupNodeEvents and cy.task for Node.js tasks like database seeding. Create custom commands with cy.session for faster, reusable login flows and DRY tests.

Unit Testing: Jest

How to install and configure Jest

Unit Testing: Jestconfig, install, jest, setup

Optimize testing performance with test doubles to isolate code from slow dependencies. Identify "seams" in your application for efficient behavior alteration. Use mock implementations to eliminate delays caused by database queries, enhancing the speed and reliability of unit tests. Balance isolation and integration testing for effective results.

Libraries: Three.js

How to create a 3D scene with Three.js

Libraries: Three.js3d, scene, setup, three.js

The render loop for real-time 3D graphics animation. Use requestAnimationFrame, not setInterval, for a smooth animation loop. This Three.js example uses an animate function to update object rotation and render the scene with the camera, creating a continuous cycle for an interactive world.