code: function processPath (sourcePath, errorMessage) {
    if (!sourcePath || typeof sourcePath !== 'string') {
      throw new Error(errorMessage);
    }
    if (!path.isAbsolute(sourcePath)) {
      sourcePath = path.join(process.cwd(), sourcePath);
    }
    return sourcePath;
  }
docs: Checks if a path exists and transforms it to an absolute if it's relative
  @param {string} sourcePath
  @param {string} errorMessage
  @returns {string}