code: function getMockServerPath(rootPath, mockServerPath) {
      let result = mockServerPath || './src';
  
      if (!path.isAbsolute(result)) {
          result = path.resolve(rootPath, result);
      }
  
      return result;
  }
docs: 获得 mock server 的根目录绝对路径
  
  @param {String} rootPath 项目根目录
  @param {String} mockServerPath
  @returns {String}