eslint-plugin-simple-header

Simple to use license header plugin for ESLint.

Installation

Add eslint-plugin-simple-header as a dev dependency using your package manager:

$ pnpm add -D eslint-plugin-simple-header
# or yarn, npm etc

Usage

Given the following configuration:

import simpleHeader from "eslint-plugin-simple-header"

export default [
  {
    plugins: {
      "simple-header": simpleHeader,
    },
    rules: {
      "simple-header/header": ["error", {
        text: [
          "Copyright (c) {year} {author}",
          "SPDX-License-Identifier: GPL-3.0-or-later",
        ],
        templates: { author: [".*", "rini"] },
      }]
    },
  },
]

The rule will match a header like this:

/*
 * Copyright (c) 1970 Linus Torvalds
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

And when running auto-fix, will insert a header like so:

/*
 * Copyright (c) 2023 Rini
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

(Where 2023 is the current year, if you are from the future)

text may be an array of lines, or an entire string. It’s also possible to give an array of paths to files. In both cases, they can include comment syntax and won’t be autoformatted (i.e. prefixed with *s).

Inside the header’s text {template} syntax can be used, which correlates to the template key. The first value is a regex used to match the header, and the second is a default value. By default, year matches \d{4} and defaults the current year.

A few other options include:

• newlines specifies exactly how many lines should be after the header, and defaults to 1. If the file is empty otherwise, no newlines are added.
• syntax specifies the comment syntax, defaults to ["/*", "*/"]. It may also be a string, for single-line comment blocks (e.g. //)
• decor specifies how the comment is formatted with a tuple of start, indent and end. When syntax is a block comment, this defaults to ["\n", " * ", "\n "], and defaults to " " otherwise.
• linebreak specifies the line ending to expect on files: "unix" for LF, "windows" for CRLF. By default it will auto-detect from the file.