在app.wepy文件下寫如下代碼，報錯，請問如何解決？

config = {
  pages: [
    'pages/index'
  ],
  window: {
    backgroundTextStyle: 'light',
    navigationBarBackgroundColor: '#fff',
    navigationBarTitleText: 'WeChat',
    navigationBarTextStyle: 'black'
  },
  tabBar: {
    color: "#7A7E83",
    selectedColor: "#3cc51f",
    borderStyle: "black",
    backgroundColor: "#ffffff",
    list: [{
      pagePath: "page/index",
      iconPath: "image/zhiling.png",
      selectedIconPath: "image/youyong.png",
      text: "組件"
    }, {
      pagePath: "page/index",
      iconPath: "image/youyong.png",
      selectedIconPath: "image/zhiling.png",
      text: "接口"
    }]
  }
}