How can I write a ESLint rule for "linebreak-style", changing depending on Windows or Unix?

Question

As we all know, the linebreaks (new line) used in Windows are usually carriage returns (CR) followed by a line feed (LF) i.e. (CRLF) whereas, Linux and Unix use a simple line feed (LF)

Now, in my case, my build server uses supports Linux and Unix format so, below rule is working perfectly on build server:

linebreak-style: ["error", "unix"]

But I am doing development on Windows and I need to update rule on each git pull/git push as below,

linebreak-style: ["error", "windows"]

So, is there any way to write a generic linebreak-style rule to support both environments, Linux/Unix and Windows?

Note: I am using ECMAScript6[js], WebStorm[ide] for development

Any solutions/suggestions would be highly appreciated. Thanks!

Answer 1

The eslint configuration file can be a regular .js file (ie, not JSON, but full JS with logic) that exports the configuration object.

That means you could change the configuration of the linebreak-style rule depending on your current environment (or any other JS logic you can think of).

For example, to use a different linebreak-style configuration when your node environment is 'prod':

module.exports = {
    "root": true,
    "parserOptions": {
        "sourceType": "module",
        "ecmaVersion": 6
    },
    "rules": {
        // windows linebreaks when not in production environment
        "linebreak-style": ["error", process.env.NODE_ENV === 'prod' ? "unix" : "windows"]
    }
};

Example usage:

$ NODE_ENV=prod node_modules/.bin/eslint src/test.js

src/test.js
  1:25  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style
  2:30  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style
  3:36  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style
  4:26  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style
  5:17  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style
  6:50  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style
  7:62  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style
  8:21  error  Expected linebreaks to be 'CRLF' but found 'LF'  linebreak-style

✖ 8 problems (8 errors, 0 warnings)

$ NODE_ENV=dev node_modules/.bin/eslint src/test.js
$ # no errors