lint-staged VS jest

We were already using lint-staged and have a pre-commit hook in place using Husky in our project for linter and prettier. So it made sense to add a check here.

Now you can config it in your package.json, here is the guide doc:

In the world of software development, maintaining consistent code quality and ensuring that the codebase adheres to predefined patterns and guidelines is crucial. However, manually enforcing these standards can be time-consuming and error-prone. This is where automation tools like Husky, Lint-Staged, Commitlint, and Commitizen come to the rescue. In this post, we will explore how these tools can be combined to streamline your development workflow.

This is wasted work that can and should be automated. Adding a linter and formatter on CI and a pre-commit hook such as lint-staged can do wonders.

lint-staged is a package that can be used to run formatting and linting commands on staged files in a Git repo.

To answer your next question: I lint and format on save, and I use Git hooks installed by Husky and executed through Lint-Staged (this tool helps ensure your Git hooks only run on modified files, etc) to ensure there are no lint or formatting errors whenever making a commit or pushing code. This is helpful for teams, as some developers tend to forget to run lint tasks, or don't have the Prettier extension installed in their IDE. If there are lint errors, the commit is rejected until fixed. YMMV - you'll need to fine-tune the strictness of this based on the team's needs.

Uses Husky Git hooks and Lint-staged pre-commit hooks.

Something else to consider is applying linting and formatting before every git commit. A package like Lint-staged only lints and formats on staged items, ensuring all pushed code follows the standards in the repo. This allows developers to have their own formatting preferences when developing, while the code homogenizes on push. Linting pre-commit also avoids strict rules like no-console or no-unused-vars restricting a developer when writing code, when it should only apply in production. Imagine not being able to console log anything during development!

Lint-Staged Docs

Additionally, there are pre-commit hooks which can be setup to seamlessly validate and modify the source code before every commit. I followed Prettier documentation to create one. I ran npx mrm@2 lint-staged which installed husky and lint-stagedand added a configuration to the project’s package.json. Then, I modified the commands a little and that's it.

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​​.