esbuild VS jest

During my search for deploying Lambdas via GitHub actions, I came across a tutorial that utilized ncc for converting TypeScript and bundling. While ncc is effective, I discovered esbuild, which proved to be significantly faster and perfectly suited to my requirements.

The advent of esbuild, the native support for ES Modules in browsers, the widespread adoption of import map, the emergence of tools like Native Federation, and the Nx ecosystem all combine to forge a flexible and well-maintained Micro Frontend Architecture.

EsBuild is a relatively new, blazing-fast JavaScript bundler and minifier. It stands out for its high performance, significantly speeding up the build process in development pipelines.

Unlike Webpack, the Vite DevServer only compiles files when they are requested. It leverages ES module imports, which allow JS files to import other files without needing to bundle them together during development. When one file changes, only that file needs to be re-compiled, and the rest can remain unchanged. Project files are compiled with Rollup.js. Third-party dependencies in node_modules are pre-compiled using the ultra-fast esbuild bundler for maximum speed, and they are cached until the dependency version changes. Vite also provides a client script for hot module reloading.

Use esbuild to build the React code into a form executable on both the server and client sides.

The functions will bundle using esbuild. For that, it is required to install esbuild globally:

TSX is the newest and most improved version of our ts-node, using ESBuild to transpile TS files to JS very quickly. The most interesting part is that TSX was developed to be a complete replacement for Node, so you can actually use TSX as a TypeScript REPL, if you install it globally with npm i -g tsx, just run tsx in your terminal and you can write TSX natively. But what's even cooler is that you can load TSX for all TypeScript files using --loader tsx when you run your file. For example, let's say we have this file called index.ts:

esbuild plus Vite is out of developer preview and enabled by default, yielding 67%, 87%, 80% speed improvements for build time, hybrid build time and hybrid serve time respectively.

Bundling with esbuild

Besides Webpack, there are many other popular web bundlers available, such as Parcel, Esbuild, Rollup, and more. They all have their own unique features and strengths, and you should make your decision based on the needs and requirements of your specific project. Please refer to their official websites for details.

GitHub | Website

Jest

you have selected a testing framework. In my case, it's Jest with Supertest

Jest, created and maintained by Facebook, is a JavaScript testing framework with a focus on simplicity. It is often recognized for its zero-configuration setup and seamless integration, especially with React applications, making it a favored choice for developers in both small-scale projects and large enterprise applications.

Jest (https://jestjs.io/)

console.error Jest encountered an unexpected token Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax. Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration. By default "node\_modules" folder is ignored by transformers. Here's what you can do: • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it. • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript • To have some of your "node\_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config. • If you need a custom transformation specify a "transform" option in your config. • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option. You'll find more details and examples of these config options in the docs: https://jestjs.io/docs/configuration For information about custom transformations, see: https://jestjs.io/docs/code-transformation

Note: I will be using Jest as testing framework throughout the examples.

We use Jest Framework for testing. Jest is not a dogma, and, of course, in its place can be any other test runner, such as Mocha or Ava. Let's focus on tests. I'll provide a short example because I don’t want to waste your time. You can find the full version here. It's crucial to read the comments in the code below. Let's go!

Jest has long been my favorite got to test runner when it comes to UI unit and integration testing. With tools like React Testing Library (Testing Library framework for React) you get the benefit of very easy to write and maintain tests, as well as a quick and efficient way to run our tests.

Jest is a well-regarded JavaScript testing framework primarily designed for React applications, although its utility extends to projects using Babel, JavaScript, Node, Angular, and Vue. Created by Facebook, Jest emphasizes ensuring the correctness of JavaScript codebases. It allows developers to write tests with a familiar, feature-rich API, making the testing process swift and enjoyable​​.