normalize

normalize.ts

/**
 * @function normalize
 * @description Normalize the path.
 * @param path The path to normalize.
 */
export function normalize(path: string): string {
  if (path === '') return '.';

  const parts = path.split(/[\\/]+/);
  const { length } = parts;

  if (length <= 1) return path;

  const segments: string[] = [parts[0]];
  const isAbsolute = /^[\\/]/.test(path);

  for (let index = 1; index < length; index++) {
    const { length } = segments;
    const segment = parts[index];
    const parent = segments[length - 1];

    switch (segment) {
      case '.':
        break;
      case '..':
        if (length > 0 && parent !== '..') {
          segments.pop();

          if (parent === '.') {
            segments.push(segment);
          }
        } else if (!isAbsolute) {
          segments.push(segment);
        }
        break;
      default:
        if (segment !== '' && parent === '.') {
          segments.pop();
        }

        segments.push(segment);
        break;
    }
  }

  return segments.join('/');
}