code: function getSourceLocation(offset) {
    const lines = new Error().stack.split(/\n/);
    const line = lines[offset] || '';
    const ret = line.match(/at (.*):(\d+):(\d+)/);
    if (!ret) {
      return { file: '', line: 0, column: 0, info: '' };
    }
    let file = ret[1];
    const ret2 = file.match(/\((.*)/);
    if (ret2) {
      file = ret2[1];
    }
    const lineNum = Number(ret[2] || 0);
    const column = Number(ret[3] || 0);
    return {
      file,
      line: lineNum,
      column,
      info: `${ file }:${ lineNum }:${ column }`,
    };
  }
docs: 获取源文件的位置信息
  
  @param {Number} offset
  @return {Object}