我正在尝试使用开玩笑来模拟Typescript类中的导入类,以下代码用于主程序(我从函数内部删除了一些代码,但仍应清楚我要做什么)
import * as SocketIO from "socket.io";
import {AuthenticatedDao} from "../../dao/authenticated.dao";
export default class AuthenticationService {
private readonly _authenticatedDao: AuthenticatedDao = AuthenticatedDao.Instance;
private readonly _io;
constructor(socketIo: SocketIO.Server) {
this._io = socketIo;
}
public authenticateUser(username: string, password: string, clientSocketId: string): void {
this._authenticatedDao.authenticateUser(username, password).then((authenticatedUser) => {
}).catch(rejected => {
});
}
}
import {createServer, Server} from 'http';
import * as express from 'express';
import * as socketIo from 'socket.io';
import {LogincredentialsDto} from "./models/dto/logincredentials.dto";
import {config} from './config/config';
import AuthenticationService from "./services/implementation/authentication.service";
import {Logger} from "./helperclasses/logger";
import {format} from "util";
export class ClassA {
private readonly _configPort = config.socketServerPort;
private readonly _logger: Logger = Logger.Instance;
private _app: express.Application;
private _server: Server;
private _io: socketIo.Server;
private _socketServerPort: string | number;
private _authenticationService: AuthenticationService;
constructor() {
this.configure();
this.socketListener();
}
private configure(): void {
this._app = express();
//this._server = createServer(config.sslCredentials, this._app);
this._server = createServer(this._app);
this._socketServerPort = process.env.PORT || this._configPort;
this._io = socketIo(this._server);
this._server.listen(this._socketServerPort, () => {
this._logger.log(format('Server is running on port: %s', this._socketServerPort));
});
this._authenticationService = new AuthenticationService(this._io);
}
private socketListener(): void {
this._io.on('connection', (client) => {
client.on('authenticate', (loginCreds: LogincredentialsDto) => {
console.log(loginCreds.username, loginCreds.password, client.id);
this._authenticationService.authenticateUser(loginCreds.username, loginCreds.password, client.id);
});
}
);
}
}
我正在尝试在“AuthenticationService”中模拟函数“authenticateUser”,而不是调用我要模拟promise的普通代码。我尝试使用https://jestjs.io/docs/en/es6-class-mocks中提供的示例,但是在尝试执行以下操作时:
import AuthenticationService from '../src/services/implementation/authentication.service';
jest.mock('./services/implementation/authentication.service');
beforeEach(() => {
AuthenticationService.mockClear();
});
it('test', () => {
// mock.instances is available with automatic mocks:
const authServerInstance = AuthenticationService.mock.instances[0];
我收到此错误:
错误:(62、31)TS2339:类型“AuthenticationService”类型上不存在属性“模拟”。
我在这里做错了什么?因为使用了promises,我是否应该以不同的方式 mock 类/函数?
最佳答案
问题AuthenticationService
的键入不包含mock
属性,因此TypeScript会引发错误。
细节jest.mock
创建模块的automatic mock,该模块“用模拟构造函数替换ES6类,并用总是返回undefined
的模拟函数替换其所有方法”。
在这种情况下,default
的authentication.service.ts
导出是ES6类,因此将其替换为模拟构造函数。
模拟构造函数具有mock
属性,但是TypeScript不知道该属性,并且仍将AuthenticationService
视为原始类型。
解决方案
使用jest.Mocked
让TypeScript知道jest.mock
引起的打字变化:
import * as original from './services/implementation/authentication.service'; // import module
jest.mock('./services/implementation/authentication.service');
const mocked = original as jest.Mocked<typeof original>; // Let TypeScript know mocked is an auto-mock of the module
const AuthenticationService = mocked.default; // AuthenticationService has correct TypeScript typing
beforeEach(() => {
AuthenticationService.mockClear();
});
it('test', () => {
// mock.instances is available with automatic mocks:
const authServerInstance = AuthenticationService.mock.instances[0];
关于typescript - 用玩笑 mock 导入的 typescript 中的类,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/53502054/