ESLint

A linter is a tool that statically analyzes your code to find potential problems. ESLint is the most popular linter for JavaScript. It helps enforce coding standards and find common errors before you even run your code. ESLint is highly configurable. You define a set of rules in a configuration file (like `.eslintrc.json`). These rules can catch a wide range of issues, from potential bugs (like using a variable before it's defined or creating unreachable code) to stylistic inconsistencies (like using tabs instead of spaces, or single quotes instead of double quotes). When ESLint finds code that violates a rule, it reports a warning or an error. Many code editors have extensions that integrate with ESLint, allowing you to see these errors directly in your editor as you type. ESLint can also be configured to automatically fix some of these problems, which helps in maintaining a consistent code style across a large project, especially when multiple developers are collaborating. By catching bugs early and enforcing a consistent style, ESLint improves code quality, readability, and maintainability, making it an essential tool for any professional JavaScript project.