ESLint VS JSLint

Have you ever used a transpiler, a linter or a code formatter, such as: Babel, ESLint or Prettier? If the answer is yes, then you've already used metaprogramming! 👏

ESLint is a JavaScript and TypeScript linting tool, which means it analyses source code and identifies possible programming problems and errors. It underlines errors in red and warnings in yellow. It is very useful to cover coding styles issues.

Best: set up an IDE (Visual Studio Code is free and an industry standard) and configure ESLint and the ESLint extension for your IDE so that you can catch errors like this before even running your script.

This is the extension for integrating the most well-known linter for JavaScript into Visual Studio Code. ESLint is a static analyzer of your source code which helps you find problems quickly. It will highlight issues in your code for all loaded files from your workspace. I don’t feel there’s much to write about here – just check their website and give this extension a try 😉

Linting is an important step in maintaining code quality, The React Library Builder uses ESLint and eslint-config-prettier for linting. You can modify linting rules by overriding them in the .eslintrc file.

Setup When I open the project in VS Code, it prompts me about ESlint and Docker apps that the project uses, so I make sure to have them. I run pnpm install command to install dependencies in the project while I'm in the project's directory folder. There are different ways to run the project in the documentation, and I want to run both frontend and backend, so I run pnpm services:start to run the project locally. If Docker is running, it should setup to host the project locally. Be sure to run pnpm services:stop when you are done, and clear the cache if you need to. If I need to use the database in some way, like testing login, I make sure to run cp ./src/db/env.example .env to get the right env file copy and then run pnpm db:init to setup the database.

ESLint to set some rules the code should abide by

We can use TypeScript compiler and ESLint for this.

Similar to how a software has integration or unit tests that are built to make sure changes in the software don’t break the entire system, we implemented tests for our documentation’s style guide using Vale and ESLint.

If you are afraid of test code leaking into the application. You can use eslint to prevent this:

I came across a problem where I had to find the ES6 features used by any javascript project and other data regarding their use. When I reached out to stackoverflow, I could find only one relevant post which asks you to use linters like jshint/jshint or compilers like babel. Jslint didn't seem to report anything specific to ES6 and Babel converts all the ES6+ features to ES5 but doesn't report anything regarding which constructs were used or how many times they were used. However, Jshint reported all ES6 features used in the code along with some metadata. And, to suit my needs, I ended up writing a python script that calls Jshint on all JS files in a project and presents the features used in the project and the number of times they were used across all files. You can find the code here : jsHintRunner

Javascript Linting parses and checks if any syntax is violating the rule. If a violation occurs, a warning is shown explaining unexpected behavior. Use the online version for small projects: JSLint, ESLint or JSHint. For larger projects, it is recommended to use a task runner like Gulp or Grunt. Linters ensure developers are following the best practices as a result of which few bugs appear during project development.

Programmers of classical languages hate JavaScript because it's prototype-based, dynamic and weakly typed (among other complaints). It's also the number one most in-demand programming language in 2022 according to a number of independent surveys. JSLint can help you write better JavaScript and JSMin can minify your code before deployment. These tools were created by Douglas Crockford. I would recommend his books JavaScript: The Good Parts for programmers coming to JavaScript for the first time, and How JavaScript Works for experienced JavaScript programmers.

This code is difficult to maintain. It is poorly modularized, isn't linted (paste your code into https://www.jslint.com and go about fixing it up), and demonstrates some rather odd idiosyncratic styles.

JSLint.