ts-jest VS ESLint

use ts-jest and set up Paths Re-Map

Jest's out of the box config for TS doesn't do any type checking. You can integrate https://kulshekhar.github.io/ts-jest/ or you can call ‘tsc’ yourself separately

ts-jest has had some strange performance issues and workarounds in the past, though I haven’t used it very recently so it might have fixed those by now.

Since we're working with TypeScript, we can use ts-jest, which conveniently brings Jest along for the ride:

I want to save you from manually copying the snippets one by one, so here is a Gist with the complete test file. This can be easily executed with Jest (or ts-jest for TypeScript).

See the Jest configuration docs to learn more about Jest configuration. ts-jest also has good documentation.

Using @swc/jest to compile code to CommonJS is much faster than babel-jest, ts-jest which have long cold starts when executing tests in a large project.

ts-jest: A transformer for handling TypeScript files.

Anyway, I ran into this exact error this morning setting up Jest for a TS script. I fixed it by just following the getting started instructions for Jest as well as ts-jest.

Do you have the need to find and fix problems in your JavaScript? Then ESLint is for you. With over 120 million downloads each month, it's definitely one of the most popular projects out there. The latest version introduces a new configuration system, designed to simplify available configuration options. Old and deprecated rules have been removed, and a new configuration inspector has been added. Check out the blog for all the highlights, and a migration guide.

ESLint: A pluggable and configurable linter tool for identifying and reporting on patterns in JavaScript.

Automating code checks with static code analysis allows us to enforce code styling effectively. By integrating tools into our workflow, we can identify errors at an early stage, while coding instead of blocking us at the end. For instance, flake8 checks Python code for style and errors, eslint performs similar checks for JavaScript, and prettier automatically formats code to maintain consistency.

If you're a developer, you're surely familiar with Prettier and ESLint. With over 8 years of existence, they have established themselves as references in the JavaScript ecosystem.

eslint is used to avoid code errors

No lint errors: The committed code does not contain any lint errors (eslint).

Let’s walk through the steps for a one-time setup to configure husky pre-commit and pre-push hooks, ESLint with code styles conventions, prettier code formatter, and lint-staged. Husky automatically runs a script on each commit or push. This is useful for linting files to enforce code styles that keeps the entire code base following conventions.

GitHub | Website

ESLint: A pluggable and configurable linter tool for identifying and reporting on patterns in JavaScript.

ESLint