Function relative

packages/qwik/src/optimizer/src/path.ts:223–320

(from: string, to: string)

  };

  const relative = function relative(from: string, to: string) {
    assertPath(from);
    assertPath(to);

    if (from === to) {
      return '';
    }

    from = resolve(from);
    to = resolve(to);

    if (from === to) {
      return '';
    }

    // Trim any leading backslashes
    let fromStart = 1;
    for (; fromStart < from.length; ++fromStart) {
      if (from.charCodeAt(fromStart) !== 47 /*/*/) {
        break;
      }
    }
    const fromEnd = from.length;
    const fromLen = fromEnd - fromStart;

    // Trim any leading backslashes
    let toStart = 1;
    for (; toStart < to.length; ++toStart) {
      if (to.charCodeAt(toStart) !== 47 /*/*/) {
        break;
      }
    }
    const toEnd = to.length;
    const toLen = toEnd - toStart;

    // Compare paths to find the longest common path from root
    const length = fromLen < toLen ? fromLen : toLen;
    let lastCommonSep = -1;
    let i = 0;
    for (; i <= length; ++i) {
      if (i === length) {
        if (toLen > length) {
          if (to.charCodeAt(toStart + i) === 47 /*/*/) {
            // We get here if `from` is the exact base path for `to`.
            // For example: from='/foo/bar'; to='/foo/bar/baz'
            return to.slice(toStart + i + 1);
          } else if (i === 0) {
            // We get here if `from` is the root
            // For example: from='/'; to='/foo'
            return to.slice(toStart + i);
          }
        } else if (fromLen > length) {
          if (from.charCodeAt(fromStart + i) === 47 /*/*/) {
            // We get here if `to` is the exact base path for `from`.
            // For example: from='/foo/bar/baz'; to='/foo/bar'
            lastCommonSep = i;
          } else if (i === 0) {
            // We get here if `to` is the root.