I am a beginner using jest to test a node/express app with mongo database.
I am getting an issue where different tests are failing each time I run the tests and sometimes they all pass/all fail. I think it is because of a time-out or things not happening in the right order because I'm getting this error:
MongoPoolClosedError: Attempted to check out a connection from closed connection pool
a) can you let me know if you think I'm on the right track?
b) if so, is the solution to make this into an async function and how can I do that? (I have tried making it into async await, using .then and also putting the code that clears the database collections into the test files instead of the helper and have had no success so far.
beforeAll( (done) => {
mongoose.connect("mongodb://127.0.0.1/jobBuddy_test", {
useNewUrlParser: true,
useUnifiedTopology: true,
})
var db = mongoose.connection;
const users = db.collection('users')
users.deleteMany({})
const applications = db.collection('applications')
applications.deleteMany({})
db.on("error", console.error.bind(console, "MongoDB connection error:"));
db.on("open", function () {
done();
});
});
afterAll(function (done) {
mongoose.connection.close(true, function () {
done();
});
});
Related
I have NestJs application with TypeORM configured with mysql. I want to have e2e(integration) test and for that reason I want to have in memory database in the tests which I configured this way:
{
type: 'sqlite',
database: ':memory:',
synchronize: true,
dropSchema: true,
entities: [`dist/**/*.entity{.ts,.js}`],
}
And the setup of the tests
beforeEach(async () => {
const moduleFixture: TestingModule =
await Test.createTestingModule({imports: [AppModule, UserModule]})
.overrideProvider(TypeOrmConfigService).useClass(MockTypeOrmConfigService)
.compile();
app = await moduleFixture.createNestApplication();
await app.init();
});
. When running the test I got
AlreadyHasActiveConnectionError: Cannot create a new connection named "default", because connection with such name already exist and it now has an active connection session.
at new AlreadyHasActiveConnectionError (/Users/user/workspace/app/src/error/AlreadyHasActiveConnectionError.ts:8:9)
at ConnectionManager.Object.<anonymous>.ConnectionManager.create (/Users/user/workspace/app/src/connection/ConnectionManager.ts:57:23)
at Object.<anonymous> (/Users/user/workspace/app/src/index.ts:228:35)
at step (/Users/user/workspace/app/node_modules/tslib/tslib.js:136:27)
at Object.next (/Users/user/workspace/app/node_modules/tslib/tslib.js:117:57)
at /Users/user/workspace/app/node_modules/tslib/tslib.js:110:75
at new Promise (<anonymous>)
at Object.__awaiter (/Users/user/workspace/app/node_modules/tslib/tslib.js:106:16)
at Object.createConnection (/Users/user/workspace/app/node_modules/typeorm/index.js:186:20)
at rxjs_1.defer (/Users/user/workspace/app/node_modules/#nestjs/typeorm/dist/typeorm-core.module.js:151:29)
(node:19140) UnhandledPromiseRejectionWarning: AlreadyHasActiveConnectionError: Caught error after test environment was torn down
If I move the setup from beforeEach in beforeAll block it's ok, but I'm afraid that when I create several specs the error will come back. How should be handled properly?
EDIT:
The problem was that each test is making a setup of the application and so creates a new connection.The solution was to use "keepConnectionAlive: true," in order all tests to reuse same connection.
keepCOnnectionAlive: true is the way to go
Using keepConnectionAlive: true produced the following error for me.
Jest did not exit one second after the test run has completed.
This usually means that there are asynchronous operations that weren't
stopped in your tests. Consider running Jest with
--detectOpenHandles to troubleshoot this issue.
Adding the below to each e2e test fixed my issue:
afterEach(async () => {
await app.close();
});
Base on 0xCAP's answer, you can do something like this also.
// jest.setup.ts
jest.mock("/path/to/database/config/object", () => {
const { databaseConfig, ...rest } = jest.requireActual("/path/to/database/config/object")
return {
...rest,
databaseConfig: {
...databaseConfig,
keepConnectionAlive: true // replace old config
}
}
})
// jest.config.js
module.exports = {
...other options
setupFilesAfterEnv: ["jest.setup.ts"],
}
Jest docs says:
Unresolved Promises
If a promise doesn't resolve at all, this error might be thrown:
(and so on)
In my case this not happen.
I have this test:
test('detect infinite loop', () => {
expect.assertions(1);
const vastPromise = VastUtils.parseFromUrl(infiniteLoopUrl);
const expectedError =
new VastError(VastErrorCodes.WRAPPER_LIMIT_REACHED);
return expect(vastPromise).rejects.toEqual(expectedError);
});
VastUtils simply fetch an XML located at infiniteLoopUrl, parse it, and if this xml point to another xml, VastUtils follow the link, parse the new xml, merge them and repeat the process.
Now, infiniteLoopUrl point to an XML that refers itself, so it is an infinite loop.
"correctly", the code follow xml link infinitely, and never resolve or reject the promise.
I expect above test fail after a certain timeout, but it didn't.
Someone can help me?
Thanks
EDIT:
I'm trying to reproduce an infinite Promise loop with a smaller example, and this is what i've noticed:
this test correctly FAIL after 5s:
test('Promise2', () => {
const genPromise = (): Promise<void> => {
return new Promise((res) => {
setTimeout(() => {
res();
}, 200);
})
.then(() => {
return genPromise();
});
};
const vastPromise = genPromise();
const expectedError =
new VastError(VastErrorCodes.WRAPPER_LIMIT_REACHED);
return expect(vastPromise).rejects.toEqual(expectedError);
});
This test DO NOT FAIL after 5s (jest remain in an infinite loop)
test('Promise', () => {
const genPromise = (prom: Promise<void>): Promise<void> => {
return prom
.then(() => {
return genPromise(Promise.resolve());
});
};
const vastPromise = genPromise(Promise.resolve());
const expectedError =
new VastError(VastErrorCodes.WRAPPER_LIMIT_REACHED);
return expect(vastPromise).rejects.toEqual(expectedError);
});
Apparently these are similar, but I don't understand the difference that cause the jest infinite loop...
Ok, I've understand the problem.
The cause is the mono thread nature of js.
In the two examples of the edit section, te first one have a timeout so there is a moment whent jest take the control and could check the timeout.
In the second one no, so jest never check the timeout.
In my real case, the problem was the fake server: it was created as:
server = sinon.fakeServer.create({
respondImmediately: true
});
respondImmediately make sinon respond syncroniously, so jest never have the control.
Creating it as:
server = sinon.fakeServer.create({
autoRespond: true
});
sinon respond after 10ms and jest can check the time passing
This question already has answers here:
How to increase timeout for a single test case in mocha
(8 answers)
Closed 5 years ago.
I have a mocha test that I am trying to run but it keeps on giving me the following error
Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called
it('should login into account', (done) => {
let user_login = require("../../data/login.json");
mongoManager.insertDocuments("user", user_login.content, () => {
loginPage.setUserName('demodgsdg');
loginPage.setPassword('123');
loginPage.submit();
browser.waitForAngularEnabled(true);
Assert.equal(element(by.id('navbar')).isDisplayed(), true, "login page is not loaded");
setTimeout(done(), 50000);
done();
});
});
Whats the best way to run an asynchronous test in mocha so that it doesnt exceed its alotted time? Or should I set the timeout on the test function
You need to do it this way
it('should login into account', function (done) {
this.timeout(50000);
let user_login = require("../../data/login.json");
mongoManager.insertDocuments("user", user_login.content, () => {
loginPage.setUserName('demodgsdg');
loginPage.setPassword('123');
loginPage.submit();
browser.waitForAngularEnabled(true);
Assert.equal(element(by.id('navbar')).isDisplayed(), true, "login page is not loaded");
setTimeout(done(), 50000);
done();
});
});
If you read https://mochajs.org/#timeouts
Passing arrow functions (“lambdas”) to Mocha is discouraged. Due to the lexical binding of this, such functions are unable to access the Mocha context. For example, the following code will fail due to the nature of lambdas:
describe('my suite', () => {
it('my test', () => {
// should set the timeout of this test to 1000 ms; instead will fail
this.timeout(1000);
assert.ok(true);
});
});
If you do not need to use Mocha’s context, lambdas should work. However, the result will be more difficult to refactor if the need eventually arises.
Ok, my mocha tests will pass if I comment out the 'before' and 'after' methods. I am sure that both of my errors are related to each other.
The 'after' method fails stating app.close isn't a function. The 'before' method fails saying it cant find 'app' on my line 7 (clearing server cache).
I am completely out of options or ideas. I would like to be able to start and stop my server at my command. This is the first time that I have attempted to include any type of 'before/after' methods to my mocha testing. working code below, but with my failing portion commented out. Any suggestions??
var request = require('supertest');
var app = require('../../server');
describe('server', function() {
before(function () {
//var app = require('../../server')();
//delete require.cache[require.resolve('app')];
});
after(function () {
//app.close();
});
describe('basic comms', function() {
it('responds to root route', function testSlash(done) {
request(app)
.get('/')
.expect('Content-type', /json/)
//.expect(res.message).to.equal('Hello World!')
.expect(200, done);
});
it('404 everything else', function testPath(done) {
//console.log('testing 404 response');
request(app)
.get('/foo/bar')
.expect(404, done);
});
});
});
In before you require your app in a different way than in line 2. Why would you not use already required app?
Example:
before(function () {
// here you can use app from line 2
});
Regarding app.close, where did you find this function?
Check Express docs:
http://expressjs.com/en/4x/api.html#app
To close express server, you can use this approach:
how to properly close node-express server?
I'm using promises to wrap asynchronous (Mongo) DB ops at the end of an (expressJS) route.
I want to try and figure out how to test the following code.
userService
userService.findOne = function (id) {
var deferred = q.defer();
User.findOne({"_id" : id})
.exec(function (error, user) {
if (error) {
deferred.reject(error);
} else {
deferred.resolve(user);
}
});
return deferred.promise;
};
userRoute
var user = function (req, res) {
var userId = req.params.id
, userService = req.load("userService");
// custom middleware that enables me to inject mocks
return userService.findOne(id)
.then(function (user) {
console.log("called then");
res.json({
msg: "foo"
});
}).catch(function (error) {
console.log("called catch");
res.json({
error: error
});
}).done();
};
Here's an attempt to test the above with mocha
userTest
it("when resolved", function (done) {
var jsonSpy = sinon.spy(httpMock.res, "json")
, httpMock = require("/path/to/mock/http/object")
, serviceMock = require("/path/to/mock/service"),
, deferred = q.defer()
, findStub = sinon.stub(serviceMock, "findOne")
.returns(deferred.promise)
, loadStub = sinon.stub(httpMock.req, "load")
.returns(serviceMock),
retPromise;
// trigger route
routes.user(httpMock.req, httpMock.res);
// force promise to resolve?
deferred.resolve();
expect(jsonSpy.called).to.be.true; // fails
// chai as promised
retPromise = findStub.returnValues[0];
expect(retPromise).to.be.fulfilled; // passes
});
the http mock is just an empty object with no-ops where expressJS would normally start rendering stuff. I've added some logging inside those no-ops to get an idea on how this is hanging together.
This isn't really working out. I want to verify how the whole is integrated, to establish some sort of regression suite - but I've effectively mocked it to smithereens and I'm just testing my mocks (not entirely successfully at that).
I'm also noticing that the console logs inside my http mocks triggered by then and catch are firing twice - but the jsonSpy that is invoked inside the actual code (verified by logging out the sinon spy within the userRoute code) is not called in test.
Has anyone got some advice on integration testing strategies for express apps backed by Mongo?
It looks to me like you're not giving your promise an opportunity to fire before you check if the result has been called. You need to wait asynchronously for userService.findOne()'s promise chain to complete before jsonSpy.called will be set. Try this instead:
// start of code as normal
q.when(
routes.user(httpMock.req, httpMock.res),
function() { expect(jsonSpy.called).to.be.true; }
);
deferred.resolve();
// rest of code as normal
That should chain off the routes.user() promise and pass as expected.
One word of caution: I'm not familiar with your framework, so I don't know if it will wait patiently for all async events to go off. If it's giving you problems calling back into your defer chain, you may want to try nodeunit instead, which handles async tests very well (IMO).