🌟 Angular ESLint + Prettier Starter

📖 Overview

This project is a starter template for Angular applications with ESLint and Prettier integrated. It ensures consistent code quality and formatting across your project, following best practices for modern Angular development.

✨ Features

• 🛠️ ESLint: Linting for TypeScript and Angular-specific files.
• 🎨 Prettier: Automatic code formatting for consistent style.
• 🎨 SCSS Support: Configured to lint SCSS files in addition to TypeScript and HTML.

🧰 Software and Tools

This project template is built using the following tools and their major versions:

• Angular: Version 19.0.5
• Angular CLI: Version 19.0.6
• Node.js: Version 22.12.0
• Yarn: Version 1.22.22
• TypeScript: Version 5.6.3
• ESLint: Version 9.17.0
• Prettier: Version 3.4.2
• @angular-eslint: Version 19.0.2

🚀 Setup Instructions (How to Use the Template)

1️⃣Step 1: Clone the Repository 🐙

git clone git@github.com:edwinmambo/angular-eslint-prettier-starter.git

Step 2: Install Dependencies 📦

Run the following command to navigate to the project directory:

cd angular-eslint-prettier-starter

Install all required dependencies using Yarn:

yarn install

Step 3: Format Code 🎯

Use the following command to format your codebase:

yarn format

To automatically fix formatting issues with Prettier, run the following command:

yarn format:fix

Step 4: Run Linting ✅

Use the following command to check your project for linting issues:

yarn lint

To automatically fix linting issues, run the following command:

yarn lint:fix

Step 5: Start the Application 🌐

Run the following command to start the Angular application:

yarn start

Navigate to http://localhost:4200/ in your browser to view the application.

🔧 How This Template Was Made

Step 1: Create an Angular Project

1. Run the Angular CLI command to create a new project:

   ng new angular-eslint-prettier-starter --style=scss --routing

   • Selected SCSS as the default style format.

2. Navigate to the project directory:

   cd angular-eslint-prettier-starter

Step 2: Add ESLint

1. Install Angular ESLint using the CLI:

   ng add @angular-eslint/schematics

2. Update the angular.json file to include the @angular-eslint/builder:lint:

   "lint": {
     "builder": "@angular-eslint/builder:lint",
     "options": {
       "lintFilePatterns": [
         "src/**/*.ts",
         "src/**/*.html",
         "src/**/*.scss"
       ]
     }
   }

3. Add rules for Angular component and directive selectors in the .eslintrc file:

   {
     "parserOptions": {
       "project": "./tsconfig.json"
     },
     "plugins": ["prettier"],
     "overrides": [
       {
         "files": ["**/*.ts"],
         "extends": [
           "eslint:recommended",
           "plugin:@typescript-eslint/recommended",
           "plugin:@typescript-eslint/stylistic",
           "plugin:@angular-eslint/recommended",
           "plugin:prettier/recommended"
         ],
         "rules": {
           "@angular-eslint/directive-selector": [
             "error",
             {
               "type": "attribute",
               "prefix": "app",
               "style": "camelCase"
             }
           ],
           "@angular-eslint/component-selector": [
             "error",
             {
               "type": "element",
               "prefix": "app",
               "style": "kebab-case"
             }
           ]
         }
       },
       {
         "files": ["**/*.html"],
         "extends": [
           "plugin:@angular-eslint/template/recommended",
           "plugin:@angular-eslint/template/accessibility"
         ],
         "rules": {
           "prettier/prettier": "error"
         }
       }
     ]
   }

Step 3: Add Prettier

1. Install Prettier and related ESLint plugins:

   yarn add --dev prettier eslint-plugin-prettier eslint-config-prettier

2. Create a .prettierrc file to configure Prettier:

   {
     "tabWidth": 2,
     "useTabs": false,
     "singleQuote": true,
     "semi": true,
     "bracketSpacing": true,
     "arrowParens": "avoid",
     "trailingComma": "es5",
     "bracketSameLine": true,
     "printWidth": 80,
     "endOfLine": "auto",
     "overrides": [
       {
         "files": "*.html",
         "options": {
           "parser": "angular"
         }
       }
     ]
   }

3. Create a .prettierignore file to exclude specific files and directories:

   node_modules/
   dist/
   coverage/
   .angular/
   

Step 4: Add a Format Script

1. Add a format script to the package.json file:

   "scripts": {
     "lint": "ng lint",
     "lint:fix": "ng lint --fix",
     "format": "prettier --check \"src/**/*.{ts,html,scss,json}\"",
     "format:fix": "prettier --write \"src/**/*.{ts,html,scss,json}\""
   }

Step 5: Run Linting and Formatting

1. Run the linting script to check for issues:

   yarn lint

2. Run the formatting script to ensure consistent code style:

   yarn format

🛠️ Integrating Husky, lint-staged, and Commitlint

To ensure high-quality commits and enforce code standards, you can integrate Husky, lint-staged, and Commitlint into your project. These tools help automate linting, formatting, and commit message validation.

Step 1: Install Dependencies

Install the required packages for Husky, lint-staged, and Commitlint:

yarn add --dev husky lint-staged @commitlint/cli @commitlint/config-conventional

Step 2: Initialize Husky 🐾

Run the following command to initialize Husky in your project:

npx husky init

This will set up a .husky directory and create a default pre-commit hook.

Step 3: Configure lint-staged 🧹

Update your package.json file to include the lint-staged configuration:

  "lint-staged": {
    "*.{ts,scss,html}": [
      "eslint --fix",
      "prettier --check"
    ]
  },

This configuration ensures that only staged files are linted and formatted.

Step 4: Add a Pre-Commit Hook 🔒

Modify the Husky pre-commit hook to use lint-staged. Open .husky/pre-commit and replace its contents with:

# .husky/pre-commit

npx lint-staged

Step 5: Set Up Commitlint 📝

1. Create a .commitlintrc configuration file in the root of your project:

   {
     "extends": ["@commitlint/config-conventional"]
   }

2. Add a Husky commit-msg hook to validate commit messages. Create a .husky/commit-msg file with the following content:

   # .husky/commit-msg
   
   npx --no-install commitlint --edit "$1"

Step 6: Test the Setup 🧪

1. Make changes to a file in your project and stage it using git add.

2. Attempt to commit your changes with an invalid commit message. For example:

   git commit -m "fixing stuff"

You should see an error because the message doesn't follow the Conventional Commits format.

3. Use a valid commit message format like this:

   git commit -m "fix: resolve linting issues in AppComponent"

Important Note: ESLint Configuration Update

If you are currently using .eslintrc and encounter compatibility issues, run the following command:

export ESLINT_USE_FLAT_CONFIG=false

Likewise, consider migrating to ESLint's flat configuration. You can do this by creating an eslint.config.js file with the following content:

// @ts-check
const eslint = require('@eslint/js');
const tseslint = require('typescript-eslint');
const angular = require('angular-eslint');
const eslintPluginPrettierRecommended = require('eslint-plugin-prettier/recommended');

module.exports = tseslint.config(
  {
    files: ['**/*.ts'],
    extends: [
      eslint.configs.recommended,
      ...tseslint.configs.recommended,
      ...tseslint.configs.stylistic,
      ...angular.configs.tsRecommended,
      eslintPluginPrettierRecommended,
    ],
    processor: angular.processInlineTemplates,
    rules: {
      '@angular-eslint/directive-selector': [
        'error',
        {
          type: 'attribute',
          prefix: 'app',
          style: 'camelCase',
        },
      ],
      '@angular-eslint/component-selector': [
        'error',
        {
          type: 'element',
          prefix: 'app',
          style: 'kebab-case',
        },
      ],
    },
  },
  {
    files: ['**/*.html'],
    extends: [
      ...angular.configs.templateRecommended,
      ...angular.configs.templateAccessibility,
    ],
    rules: {},
  }
);

Commit Message Format

Follow the Conventional Commits format for your commit messages:

• feat: A new feature
• fix: A bug fix
• docs: Documentation updates
• style: Code style changes (e.g., formatting)
• refactor: Code restructuring without feature or bug changes
• test: Adding or updating tests
• chore: Maintenance tasks (e.g., updating dependencies)

Example:

feat: add user authentication feature

🎉 You're All Set!

With Husky, lint-staged, and Commitlint integrated, your project now has robust pre-commit and commit message validation, ensuring code quality and team collaboration standards. 🚀

🎉 Conclusion

This project template provides a solid foundation for Angular applications with ESLint and Prettier integrated. It ensures consistent code quality and formatting across your project, following best practices for modern Angular development.

Feel free to customize the ESLint and Prettier configurations to suit your specific needs and preferences. Happy coding! 💻🎨