Question

我正在使用打字稿中的jest / ts-jest编写单元测试，并且尝试模拟一个类，但遇到TypeError。 “ storage_1.default不是构造函数”。

这是我模拟课堂的方式。

index.test.ts

import GetAdaptiveCard from '../../GetAdaptiveCard/index'

const mockGetAdaptiveCard = jest.fn();
jest.mock('../../utils/storage', () => {
    return jest.fn().mockImplementation(() => {
        return {
            getAdaptiveCard: mockGetAdaptiveCard
        }   
    })
})
test('http trigger should return adaptive card', async () => {
....
    await GetAdaptiveCard(context, req);//calls AdaptiveCardStorage. The class I am mocking in "../../utils/storage"
...
});

index.ts

import AdaptiveCardsStorage from '../utils/storage';
...
const storage: AdaptiveCardsStorage = new AdaptiveCardsStorage(); //This is where I get the TypeError
const adaptiveCard: string = await storage.getAdaptiveCard(userID, cardName);

utils / storage.ts

export default class AdaptiveCardsStorage {
    /**
     * 
     * Class to interface with adaptive cards storage.
     * 
     */

    private tableService: storage.TableService;
    private tableName: string = Config["TABLE_STORAGE_TABLE_NAME"];

    public constructor() {
        this.tableService = storage.createTableService();
    }

    public async getAdaptiveCard(userID: string, cardName: string): Promise<string> {
        return new Promise((resolve, reject) => {
            this.tableService.retrieveEntity<any>(this.tableName, userID, cardName, (err, result) => {
                if (!err) {
                    resolve(result.Content["_"]);
                } else {
                    reject(err);
                }
            });
        });
    }

}

这就是我得到的。

    TypeError: storage_1.default is not a constructor


const handleRequest = async function (userID: string, cardName: string, context: Context) {
const storage: AdaptiveCardsStorage = new AdaptiveCardsStorage();
         |                                           ^
const adaptiveCard: string = await storage.getAdaptiveCard(userID, cardName);

at GetAdaptiveCard/index.ts:19:
at dist/GetAdaptiveCard/index.js:7:71
at Object.<anonymous>.__awaiter (dist/GetAdaptiveCard/index.js:3:12)
at handleRequest (dist/GetAdaptiveCard/index.js:29:
at Object.<anonymous> (GetAdaptiveCard/index.ts:9:29)
at dist/GetAdaptiveCard/index.js:7:71

Answer 1

由于您正在使用ES2015 import来编写代码，因此希望模块的default导出可用，但是在模拟中您不会提供。修复非常简单：

jest.mock('../../utils/storage', () => {
    return { // need to add this nested `default` property
        default: jest.fn().mockImplementation(() => {
            return {
                getAdaptiveCard: mockGetAdaptiveCard
            }   
        })
    }
})

Answer 2

请记住，只是为了响应Dmitriy，如果您以val borrowerPartyFuture = lenderNode.startFlow(RequestKeyForAccount(borrowerAccount)) val lenderPartyFuture = lenderNode.startFlow(RequestKeyForAccount(lenderAccount))这样的方式导出类，则会在模拟中反映该名称空间。

//If you don't do this you can't lookup accounts by PublicKey on the other host
subFlow(ShareStateAndSyncAccounts(state, lenderAccount.state.data.host))

在使用jest / ts-jest模拟打字稿中的类时，出现“ TypeError：“ X”。默认不是构造函数。“

2 个答案: