chai VS ESLint

Let's configure tests with mocha, chai and sinon on Typescript in a few steps.

For those of you wondering what a "Chaijs" is like I was: https://github.com/chaijs/chai

> BDD / TDD assertion framework for node.js and the browser that can be paired with any testing framework.

ES6 test setup with Mocha and Chai.

It'd be hard for me to imagine what would it be like back then to write tests if it wasn't for Enzyme. Even with Enzyme, it was noticeably harder than it is today, and I still vividly remember installing and configuring in my project Mocha, Chai, Sinon, and JSDOM, to get pretty much the same tooling that today a single library - Jest - provides out of the box, while adding numerous features on top of that.

The library offers a BDD testing style and fully exploits javascript promises - the resulting tests are simple, clear and expressive. Chakram is built on node.js, mocha, chai and request.

For this example, I am using Mocha, plus Chai for its BDD expect syntax and the chai-as-promised plugin for asynchronous matchers.

chai

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

1. Lack of Static Code Analysis Static code analysis tools like TypeScript and ESLint play a crucial role in identifying and preventing bugs. TypeScript provides static typing, enhancing the robustness of the code. ESLint detects issues and enforces coding standards. The absence of these tools can significantly elevate the likelihood of bugs due to the lack of early detection and guidance provided during development.

The industry standard for JavaScript is ESLint. VS Code has an ESLint extension. Here is a guide.

All modern linters incorporate functionality for extending configurations, although the syntax for this is often implemented differently. Taking ESLint as an example, in its latest versions, the primary extension method is through the use of the spread operator. Let's take a look at an example:

The next tool is ESLint. This tool helps you find issues in your code and highlights errors. You'll find many plugins for ESLint that can help you configure it the way you want, or you can even use shared configs.

Linters: Tools like ESLint, TSLint, SwiftLint, etc., can help you adhere to a consistent code style and identify potential errors.