Configuring Line Endings with ESLint and Prettier

When working on a project that involves multiple developers, maintaining consistency in code formatting is crucial. Two popular tools for achieving this are ESLint and Prettier. However, when using these tools together, you may encounter issues related to line endings, particularly if your team members use different operating systems. In this tutorial, we’ll explore how to configure line endings with ESLint and Prettier to avoid common problems.

Understanding Line Endings

Before diving into the configuration, it’s essential to understand how line endings work on different platforms:

• Windows: Uses both a carriage return (CR) and a line feed (LF) character (\r\n) to indicate a new line.
• Mac (older versions): Used only a carriage return (CR) character (\r).
• Linux and Mac (newer versions): Use only a line feed (LF) character (\n).

When collaborating on a project, these differences can cause issues if not properly handled.

Configuring ESLint and Prettier

To configure ESLint and Prettier to handle line endings correctly, you’ll need to modify your .eslintrc.json and/or .prettierrc files. Here are the steps:

1. Configure Prettier:
   In your .prettierrc file (or .prettierrc.json), add the following configuration:

   {
     "endOfLine": "auto"
   }
   

   This setting tells Prettier to automatically detect and use the correct line ending for your system.

2. Configure ESLint:
   In your .eslintrc.json file, you can configure ESLint to work with Prettier’s line ending settings by adding the following rule:

   "rules": {
     "prettier/prettier": [
       "error",
       {
         "endOfLine": "auto"
       }
     ]
   }
   

   This configuration ensures that ESLint respects Prettier’s line ending settings.

Additional Considerations for Windows Users

If you’re working on a Windows machine, Git might automatically convert line endings to CRLF when cloning a repository. To avoid this issue, you can configure Git to disable automatic line ending conversion by running the following command:

git config --global core.autocrlf false

After making this change, you may need to re-clone your repository or manually adjust the line endings in your existing project.

Configuring VSCode

Additionally, if you’re using Visual Studio Code (VSCode), you can configure it to use the correct line ending for your system. To do so:

1. Open your project in VSCode.
2. Click on the status bar at the bottom of the window, where it indicates the current line ending (e.g., "LF" or "CRLF").
3. Select the desired line ending from the dropdown menu.

By following these steps and configurations, you can ensure that ESLint and Prettier work together seamlessly to maintain consistent line endings in your project, regardless of the operating systems used by your team members.