stylelint-header

A stylelint custom rule to check for a header comment (i.e., copyright notice).

This rule will cause stylelint to throw an error if no header exists in the file or if autofix is enabled, it will prepend the header to the document.

Installation

yarn add -D stylelint-header

npm install --dev stylelint-header

Options

templateVariables

Type object; Default {}

This is an object of key/value pairs that will be used to replace variables in the header template. For example, if you have a header template that looks like this:

(c) <%= YEAR %> <%= company %>

You can pass in an object like this:

{
  templateVariables: {
    company: "Adobe",
  },
}

And the resulting header will look like this:

/*!
 * (c) 2025 Adobe
 */

Notice that the YEAR variable was replaced with the current year but not provided in the templateVariables object. This variable is automatically supported by the plugin.

The following variables are supported by default:

• YEAR: The current year
• FILE_NAME: The name of the file being linted
• FILE_PATH: The path to the file being linted

This plugin is using lodash.template to replace variables in the header template. Please refer to the lodash documentation for more information on how to use this feature.

nonMatchingTolerance

Type numeric; Default 0.98

This is a number between 0 and 1 representing the percentage of allowed difference between a found comment in the file and the provided header. Uses string-similarity to determine value.

isRemovable

Type boolean; Default false

This setting determines whether the comment starts with /*!, a special syntax that is often retained even when other comments are stripped by minifiers such as cssnano. If set to true, copyright comments will be added with /* only; by default all comments use /*!.

Usage

Add it to your stylelint config plugins array, then add header/header to your rules, specifying a string or file location for the header template. To toggle the rule off, set the rule to null.

To leverage the plugin with a hardcoded template string and a custom tolerance:

{
  "plugins": ["stylelint-header"],
  "rules": {
    "header/header": [
      "Copyright <%= YEAR %>. <%= company %>",
      {
        templateVariables: {
          company: "Adobe",
        },
        nonMatchingTolerance: 0.8
      }
    ],
  },
};

To leverage the plugin with a path to a file containing the header template:

{
  "plugins": ["stylelint-header"],
  "rules": {
    "header/header": ["./COPYRIGHT"],
  },
};