reprism/src/languages/diff.js

Modular Syntax highlighting for the web

export default {
  language: 'diff',
  init: Prism => {
    Prism.languages.diff = {
      coord: [
        // Match all kinds of coord lines (prefixed by "+++", "---" or "***").
        /^(?:\*{3}|-{3}|\+{3}).*$/m,
        // Match "@@ ... @@" coord lines in unified diff.
        /^@@.*@@$/m,
        // Match coord lines in normal diff (starts with a number).
        /^\d+.*$/m,
      ],

      // Match inserted and deleted lines. Support both +/- and >/< styles.
      deleted: /^[-<].*$/m,
      inserted: /^[+>].*$/m,

      // Match "different" lines (prefixed with "!") in context diff.
      diff: {
        pattern: /^!(?!!).+$/m,
        alias: 'important',
      },
    }
  },
}