如何在 Typescript 中模拟 Cognito 响应

Posted 2023-03-07

【中文标题】如何在 Typescript 中模拟 Cognito 响应

【英文标题】：How to mock Cognito response in Typescript

【发布时间】：2021-08-27 22:22:46

【问题描述】：

定义class CognitoPool后保存为cognitoPool.ts脚本：

const AWS = require('aws-sdk');
import  CognitoIdentityServiceProvider  from 'aws-sdk';
import ListUsersRequest, ListUsersResponse from 'aws-sdk/clients/cognitoidentityserviceprovider';

export class CognitoPool 
  private identityService: CognitoIdentityServiceProvider;

  constructor(identityService: CognitoIdentityServiceProvider)     
    this.identityService = identityService;
  

  async listCognitoUsers(poolID: string, sub: string): Promise<ListUsersResponse> 

    let params = 
      UserPoolId: poolID,
      Filter: `sub="$sub"`
     as ListUsersRequest;

    let res: ListUsersResponse = await this.identityService.listUsers(params).promise();
    return res;
  


export default new CognitoPool(new AWS.CognitoIdentityServiceProvider());

我继续写一个测试脚本：

const AWS = require('aws-sdk');
import sinon,  stubObject  from 'ts-sinon'
import  CognitoIdentityServiceProvider, AWSError  from 'aws-sdk';
import  PromiseResult  from 'aws-sdk/lib/request';
import  CognitoPool  from './cognitoPool';


describe('Testing', () => 

  const identityService = new AWS.CognitoIdentityServiceProvider();

  const stub = stubObject(identityService);

  const cognitoPool = new CognitoPool(stub);

  it('Test 01', async () => 

    let mockData = 
      Users: []
     as unknown as PromiseResult<any, AWSError>;
    
    stub.listUsers.returns(mockData); 

    let result = await cognitoPool.listCognitoUsers('poolId-123', 'sub-123');

  )

)

mockData 将由 identityService.listUsers() 返回为 as PromiseResult：

    let mockData = 
      Users: []
     as unknown as PromiseResult<any, AWSError>;

但测试脚本运行时出现错误：

TypeError: this.identityService.listUsers(...).promise is not a function

有没有办法避免这个错误？

【参考方案1】：

PromiseResult 是一个包含.promise 作为函数的对象。然后，当你想模拟一个函数返回一个PromiseResult，模拟数据应该是一个像PromiseResult这样的对象。

在您的情况下，mockData 应该是：

const mockData = 
  promise: () => Promise.resolve( Users: [] ),
 as unknown as PromiseResult<any, AWSError>;