UnhandledPromiseRejectionWarning:错误:网络错误: apollo_cache_inmemory_1.readQueryFromStore不是函数

Question

我试图通过nodejs为我的AWS AppSync应用程序调用Graphql查询。我遇到的错误是

UnhandledPromiseRejectionWarning:错误:网络错误: apollo_cache_inmemory_1.readQueryFromStore

这是我的index.js代码

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var config = {
AWS_ACCESS_KEY_ID: <ACCESS_KEY_ID>,
AWS_SECRET_ACCESS_KEY: <SECRET_KEY>,
HOST: '<HOST_URL>',
REGION: 'us-west-2',
PATH: '/graphql',
ENDPOINT: '<AWS_APPSYNC_ENDPOINT>',
};

config.ENDPOINT = "https://" + config.HOST + config.PATH;
exports.default = config;

global.localStorage = {
    store: {},
    getItem: function (key) {
        return this.store[key]
    },
    setItem: function (key, value) {
        this.store[key] = value
    },
    removeItem: function (key) {
        delete this.store[key]
    }
};

require('es6-promise').polyfill();
require('isomorphic-fetch');

// Require AppSync module
const AUTH_TYPE = "AWS_IAM";
const AWSAppSyncClient = require('aws-appsync').default;

const url = config.ENDPOINT;
const region = config.REGION;
const type = AUTH_TYPE.AWS_IAM;

// If you want to use API key-based auth
const apiKey = 'xxxxxxxxx';
// If you want to use a jwtToken from Amazon Cognito identity:
const jwtToken = 'xxxxxxxx';

// If you want to use AWS...
const AWS = require('aws-sdk');
AWS.config.update({
    region: config.REGION,
    credentials: new AWS.Credentials({
        accessKeyId: config.AWS_ACCESS_KEY_ID,
        secretAccessKey: config.AWS_SECRET_ACCESS_KEY
    })
});
const credentials = AWS.config.credentials;

// Import gql helper and craft a GraphQL query
const gql = require('graphql-tag');
const query = gql(`
    query {
        getSample {
            mobileNumber
        }
    }
`);

// Set up Apollo client
const client = new AWSAppSyncClient({
    url: url,
    region: region,
    auth: {
        type: type,
        credentials: credentials,
    }
});

client.hydrated().then(function a(client) {
    client.query({query: query});
    client.query({ query: query, fetchPolicy: 'network-only'}).then(function(data) {
        console.log("data: " + queryResult);
    })
});

完整的堆栈跟踪如下：

错误:网络错误:在(/Users/kanhaiagarwal/appsync1/node_modules/aws-appsync/node_modules/apollo-client/bundle.umd.js:124:32) /Users/kanhaiagarwal/appsync1/node_modules/aws-appsync/node_modules/apollo-client/bundle.umd.js:1248:45 at /Users/kanhaiagarwal/appsync1/node_modules/aws-appsync/node_modules/的新ApolloError中apollo_cache_inmemory_1.readQueryFromStore不是一个函数阿波罗-client/bundle.umd.js:1680:21在/Users/kanhaiagarwal/appsync1/node_modules/aws-appsync/node_modules/apollo-client/bundle.umd.js:1679:22 at Map.forEach () at Map.forEach () at QueryManager.broadcastQueries (/Users/kanhaiagarwal/appsync1/node_modules/aws-appsync/node_modules/apollo-client/bundle.umd.js:1672:26) at /Users/kanhaiagarwal/appsync1 1/node_modules/aws-appsync/node_modules/apollo-client/bundle.umd.js:1175:35 at (节点:23377) UnhandledPromiseRejectionWarning:未处理的承诺拒绝。此错误起源于在异步函数中抛出而不带catch块，或者拒绝使用.catch()处理的承诺。(拒绝id: 1) (节点:23377) DEP0018 DeprecationWarning:未处理的承诺拒绝被取消。在未来，承诺不处理的拒绝将使用非零退出代码终止Node.js进程。

有人能为这件事提出解决方案吗？

Answer 1

造成此问题的原因是没有为某些全局对象提供appsync包所依赖的window对象。这在Node.js环境中是不存在的，在脚本开始时添加以下内容应该可以使其工作：

global.window = global.window || {
    setTimeout: setTimeout,
    clearTimeout: clearTimeout,
    WebSocket: global.WebSocket,
    ArrayBuffer: global.ArrayBuffer,
    addEventListener: function () { },
    navigator: { onLine: true }
};

下面是提出答案的GitHub问题：

https://github.com/awslabs/aws-mobile-appsync-sdk-js/issues/276#issuecomment-432983691