reprism/src/languages/javascript.js

Modular Syntax highlighting for the web

export default {
  language: 'javascript',
  init: Prism => {
    Prism.languages.javascript = Prism.languages.extend('clike', {
      keyword: /\b(?:as|async|await|break|case|catch|class|const|continue|debugger|default|delete|do|else|enum|export|extends|finally|for|from|function|get|if|implements|import|in|instanceof|interface|let|new|null|of|package|private|protected|public|return|set|static|super|switch|this|throw|try|typeof|var|void|while|with|yield)\b/,
      number: /\b(?:0[xX][\dA-Fa-f]+|0[bB][01]+|0[oO][0-7]+|NaN|Infinity)\b|(?:\b\d+\.?\d*|\B\.\d+)(?:[Ee][+-]?\d+)?/,
      // Allow for all non-ASCII characters (See http://stackoverflow.com/a/2008444)
      function: /[_$a-z\xA0-\uFFFF][$\w\xA0-\uFFFF]*(?=\s*\()/i,
      operator: /-[-=]?|\+[+=]?|!=?=?|<<?=?|>>?>?=?|=(?:==?|>)?|&[&=]?|\|[|=]?|\*\*?=?|\/=?|~|\^=?|%=?|\?|\.{3}/,
    })

    Prism.languages.insertBefore('javascript', 'keyword', {
      regex: {
        pattern: /((?:^|[^$\w\xA0-\uFFFF."'\])\s])\s*)\/(\[[^\]\r\n]+]|\\.|[^/\\\[\r\n])+\/[gimyu]{0,5}(?=\s*($|[\r\n,.;})]))/,
        lookbehind: true,
        greedy: true,
      },
      // This must be declared before keyword because we use "function" inside the look-forward
      'function-variable': {
        pattern: /[_$a-z\xA0-\uFFFF][$\w\xA0-\uFFFF]*(?=\s*=\s*(?:function\b|(?:\([^()]*\)|[_$a-z\xA0-\uFFFF][$\w\xA0-\uFFFF]*)\s*=>))/i,
        alias: 'function',
      },
      constant: /\b[A-Z][A-Z\d_]*\b/,
    })

    Prism.languages.insertBefore('javascript', 'string', {
      'template-string': {
        pattern: /`(?:\\[\s\S]|[^\\`])*`/,
        greedy: true,
        inside: {
          interpolation: {
            pattern: /\$\{[^}]+\}/,
            inside: {
              'interpolation-punctuation': {
                pattern: /^\$\{|\}$/,
                alias: 'punctuation',
              },
              rest: Prism.languages.javascript,
            },
          },
          string: /[\s\S]+/,
        },
      },
    })

    if (Prism.languages.markup) {
      Prism.languages.insertBefore('markup', 'tag', {
        script: {
          pattern: /(<script[\s\S]*?>)[\s\S]*?(?=<\/script>)/i,
          lookbehind: true,
          inside: Prism.languages.javascript,
          alias: 'language-javascript',
          greedy: true,
        },
      })
    }

    Prism.languages.js = Prism.languages.javascript
  },
}