ESLint

A static code analysis tool for identifying and fixing problems in JavaScript code, enforcing code quality and consistency across projects.

Overview

ESLint is a pluggable linting utility for JavaScript that helps identify and fix problems in your code before runtime. It can detect syntax errors, potential bugs, code style issues, and violations of best practices. ESLint is highly configurable and can be integrated into your development workflow.

Example

javascript
// .eslintrc.json configuration
{
  "extends": ["eslint:recommended", "plugin:react/recommended"],
  "parserOptions": {
    "ecmaVersion": 2021,
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true
    }
  },
  "rules": {
    "semi": ["error", "always"],
    "quotes": ["error", "single"],
    "no-unused-vars": "warn",
    "no-console": "off"
  }
}

// Code with linting errors
const x = 5  // Missing semicolon
console.log("Hello")  // Wrong quotes

// Corrected code
const x = 5;
console.log('Hello');

Key Points

  • Finds problems in JavaScript code
  • Enforces coding standards
  • Highly customizable rules
  • Auto-fix capability for many issues
  • Integrates with editors and build tools

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