我正在对Express应用程序进行单元测试。我试图模拟我的外部依赖关系(Express,数据库等),并且快要突破了。
但是,我遇到的问题是无法从我的业务逻辑中的.then()
内部调用存根。
我尝试测试的几种方法如下:
/**
* Ping
* A simple endpoint to poke for testing.
* @arg {*} request - Incoming request
* @arg {*} response - Outgoing response
* @arg {*} next - Next route in series
*/
ping: (request, response, next) => {
let elapsed = Date.now() - request.start;
response.status(200).json({
request_started: new Date(request.start).toISOString(),
request_duration: `${elapsed} milliseconds`
});
},
/**
* Registration
* Allows for registration of a user name and password.
* @arg {*} request - Incoming request
* @arg {*} response - Outgoing response
* @arg {*} next - Next route in series
*/
register: (request, response, next) => {
let username = request.body.username;
let password = request.body.password;
this.model.registerUser(username, password).then(ret => {
if (ret) {
response.status(201).send("Created");
} else {
response.status(400).send("Error processing registration request. Please try again.");
}
}).catch(err => {
response.status(400).send("Error processing registration request. Please try again.");
});
}
register
中的模型返回一个Promise
,该包裹包装对数据库的调用并根据结果进行回复。我对此设置进行了模拟,如下所示:
mockModel: {
registerUser: sinon.stub().callsFake(function(user, pass) {
if (typeof user !== 'undefined') {
return Promise.resolve(pass === 'pass');
}
}),
getUser: sinon.stub().callsFake(function(user, pass) {
if (typeof user !== 'undefined' && pass === 'pass') {
return Promise.resolve({id: 9999});
} else {
return Promise.resolve(false);
}
})
}
我还模拟了response
对象,因此可以将其传递并确定其是否正确调用:
mockRes: () => {
return {
status: sinon.stub().returnsThis(),
send: sinon.stub(),
json: sinon.stub()
};
}
问题出在我参加考试时:
describe('Register() method', function() {
this.beforeEach(function() {
req = mockReq(0, {}, {username: 'user', password: 'pass'});
res = mockRes();
base.BaseRoutes(router, null, base.methods, mockModel);
});
it('Returns a 201 Created message upon success', function() {
base.methods.register(req, res);
chai.expect(res.status).to.have.been.calledWith(201);
chai.expect(res.send).to.have.been.calledWith('Created');
});
});
此处的测试失败,并出现以下错误:
1) Base Methods
Register() method
Returns a 201 Created message upon success:
AssertionError: expected stub to have been called with arguments 201
at Context.<anonymous> (test\spec.js:50:50)
单步调试器表明该方法已被调用,但我遇到了这种失败。
同一套件中利用相同模拟请求/响应的其他测试可以正常工作,但它们不使用Promise
调用(例如:ping()方法)
我怀疑它与范围界定有关,但是我不确定哪里出了问题。
答案 0 :(得分:0)
再运行几次后,我发现这不是范围问题,而是异步问题。在Promise
解决/拒绝之前,测试用例已经完成。
关闭循环的缺失是我的Express路由处理程序需要返回他们创建的Promise
来处理数据库调用:
register: (request, response, next) => {
let username = request.body.username;
let password = request.body.password;
return this.model.registerUser(username, password).then((ret) => {
if (ret) {
response.status(201).send("Created");
} else {
response.status(400).send("Error processing registration request. Please try again.");
}
}, (err) => {
response.status(400).send("Error processing registration request. Please try again.");
});
},
然后进行测试,在返回的then()
的{{1}}中执行我的断言:
Promise
虽然有将it('Returns a 201 Created message upon success', function(done) {
base.methods.register(req, res).then(x => {
chai.expect(res.status).to.have.been.calledWith(201);
chai.expect(res.send).to.have.been.calledWith('Created');
}).then(done, done);
});
it('Returns a 400 message upon failure', function(done) {
req = mockReq(0, {}, {username: 'user', password: 'fail'});
base.methods.register(req, res).then(x => {
chai.expect(res.status).to.have.been.calledWith(400);
chai.expect(res.send).to.have.been.calledWith(sinon.match.string);
}).then(done, done);
传递到测试并在那里进行处理的示例,以及分别测试Express路由处理程序的示例,但我找不到将两者结合起来并对其进行测试的示例。希望这可以为其他人服务。