Function normalize

lib/path.js:350–481

* @param {string} path * @returns {string}

(path)

   * @returns {string}
   */
  normalize(path) {
    validateString(path, 'path');
    const len = path.length;
    if (len === 0)
      return '.';
    let rootEnd = 0;
    let device;
    let isAbsolute = false;
    const code = StringPrototypeCharCodeAt(path, 0);

    // Try to match a root
    if (len === 1) {
      // `path` contains just a single char, exit early to avoid
      // unnecessary work
      return isPosixPathSeparator(code) ? '\\' : path;
    }
    if (isPathSeparator(code)) {
      // Possible UNC root

      // If we started with a separator, we know we at least have an absolute
      // path of some kind (UNC or otherwise)
      isAbsolute = true;

      if (isPathSeparator(StringPrototypeCharCodeAt(path, 1))) {
        // Matched double path separator at beginning
        let j = 2;
        let last = j;
        // Match 1 or more non-path separators
        while (j < len &&
               !isPathSeparator(StringPrototypeCharCodeAt(path, j))) {
          j++;
        }
        if (j < len && j !== last) {
          const firstPart = StringPrototypeSlice(path, last, j);
          // Matched!
          last = j;
          // Match 1 or more path separators
          while (j < len &&
                 isPathSeparator(StringPrototypeCharCodeAt(path, j))) {
            j++;
          }
          if (j < len && j !== last) {
            // Matched!
            last = j;
            // Match 1 or more non-path separators
            while (j < len &&
                   !isPathSeparator(StringPrototypeCharCodeAt(path, j))) {
              j++;
            }
            if (j === len || j !== last) {
              if (firstPart === '.' || firstPart === '?') {
                // We matched a device root (e.g. \\\\.\\PHYSICALDRIVE0)
                device = `\\\\${firstPart}`;
                rootEnd = 4;
                const colonIndex = StringPrototypeIndexOf(path, ':');
                // Special case: handle \\?\COM1: or similar reserved device paths
                const possibleDevice = StringPrototypeSlice(path, 4, colonIndex + 1);
                if (isWindowsReservedName(possibleDevice, possibleDevice.length - 1)) {