javascript - 如何在 GraphQL 中处理错误并发送响应

Question

我从 GraphQL 开始，我无法理解如何在 GraphQL 中抛出错误

我浏览了网络上的几篇文章，但几乎所有文章都使用 Apollo，而且代码结构看起来与我的工作方式大不相同。

考虑这段代码，我在这里进行突变，现在如何发送带有错误的响应消息并在出现错误时更改 header 状态消息？

  AddNewPersonalInfo: {
  type: userDashboardType,
  args: { 
    parameter: {
      type: userCreationlInputType
    }
  }, 
  resolve: async (parent, args, context) => {
    args.parameter.userId = context.req.headers.userId
    //Check if user info already exsist
    const checkIfUserInformationExsist = await getSelectedThingFromTable('CatsWork_personal', 'userId', `${userId}`)
    if (checkIfUserInformationExsist[0]) {
      const error = {
        code: 403, 
        message: 'User info Already exsist'
      }
      throw new Error(error)
    } else {
      try {
      const addLinkedinUser = await insertIntheTable('personal', payload)
      return true
      } catch (err) {
        console.error(err)
        throw new Error(err)
      }
    }
  }
}

Answer 1

我在我的一个项目中遇到过，很难设置响应的状态码。因此，我使用 express-graphql 进行了一些自定义错误响应以识别正确的 statusCode

以下是示例(我在其中一个项目中使用的):

--------app.js 文件--------

const graphqlHTTP = require('express-graphql')

app.use('/graphql', (req, res) => {
  graphqlHTTP({
    schema: GraphQLSchema, //A GraphQLSchema instance from GraphQL.js. A schema must be provided.
    graphiql: true,
    context: { req },
    formatError: (err) => {
      const error = getErrorCode(err.message)
      return ({ message: error.message, statusCode: error.statusCode })
    }
  })(req, res)
})

--------getErrorCode函数实现--------

const { errorType } = require('../constants')

const getErrorCode = errorName => {
  return errorType[errorName]
}

module.exports = getErrorCode

--------Constant.js 文件--------

exports.errorName = {
  USER_ALREADY_EXISTS: 'USER_ALREADY_EXISTS',
  SERVER_ERROR: 'SERVER_ERROR'
}

exports.errorType = {
  USER_ALREADY_EXISTS: {
    message: 'User is already exists.',
    statusCode: 403
  },
  SERVER_ERROR: {
    message: 'Server error.',
    statusCode: 500
  }
}

---

现在，我们可以使用我们的设置了。

从您的查询或突变中，您需要需要常量文件并返回自定义错误:

const { errorName } = require('../constant')

AddNewPersonalInfo: {
  type: userDashboardType,
  args: { 
    parameter: {
      type: userCreationlInputType
    }
  }, 
  resolve: async (parent, args, context) => {
    args.parameter.userId = context.req.headers.userId
    //Check if user info already exsist
    const checkIfUserInformationExsist = await getSelectedThingFromTable('CatsWork_personal', 'userId', `${userId}`)
    if (checkIfUserInformationExsist[0]) {
      const error = {
        code: 403, 
        message: 'User info Already exsist'
      }
      throw new Error(errorName.USER_ALREADY_EXISTS) // Here you can use error from constatnt file
    } else {
      try {
      const addLinkedinUser = await insertIntheTable('personal', payload)
      return true
      } catch (err) {
        console.error(err)
        throw new Error(errorName.SERVER_ERROR) // Here you can use error from constatnt file
      }
    }
  }
}

--------错误响应--------

{
  error: [{
    "statusCode": 403,
    "message": "User is already exists."
  }],
  data: null
}

我们也只需要从 FS 端编写自定义错误处理。

Note:- formatError: is deprecated and replaced by customFormatErrorFn. It will be removed in version 1.0.0. You can refer customFormatErrorFn.