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: /(^|[^/])\/(?!\/)(\[[^\]\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',
  },
});

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;
