I have a page with custom window.addEventListener("error", ...) logic. I'd like to test that it works, and the only real way to do so is to throw an error.
I tried this:
await browser.executeScript("throw new Error();");
...but Selenium itself saw the error and considered it an exception. Fine.
JavascriptError: Error
at Object.throwDecodedError (node_modules/selenium-webdriver/lib/error.js:550:15)
at parseHttpResponse (node_modules/selenium-webdriver/lib/http.js:542:13)
at Executor.execute (node_modules/selenium-webdriver/lib/http.js:468:26)
Next, tried doing that asynchronously:
await browser.executeScript(() => {
setTimeout(() => { throw new Error(); }, 1);
});
...but the page itself didn't notice the error (and yes, I've validated that throwing one in the dev tools triggers the expected handling).
Next, I tried using an async script that schedules an error and then the callback:
await browser.executeAsyncScript((callback) => {
setTimeout(
() => {
setTimeout(callback, 1);
throw new Error();
},
1);
});
...but the page itself still didn't notice the error.
Am I missing something here?
You can easily simulate that using below script
var errorElem = document.createElement("script");
errorElem.textContent = 'throw new Error("simulated error");'
document.body.append(errorElem);
This should be able to simulate the event
Related
I'm writting tests with sinon for a section of Vue code that performs a reload with window.location.reload();.
The code works correctly, but the test is failing with an error Error: Not implemented: navigation (except hash changes)
If I delete that line of code, the tests don't crash.
How can I write a sinon test that runs correctly through that line of code?
I'm not sure if I need to stub that line, although I'm not sure how could I do it for a property.
Any ideas?
Consider onbeforeunload which throws an error and prevents an actual page reloading, and assert.throws catching the error. Something like this:
describe("#location.reload", () => {
it("works well", () => {
window.onbeforeunload = () => {
throw new Error();
};
assert.throws(location.reload);
});
});
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
I've started to work with protractor + Jasmine for E2E testing.
The idea is to do an invalid operation and catch the exception:
expect(function () { return documentsPanel.clickUploadButtonError(); }).toThrow();
The documentsPanel is just a page object with multiple page actions. This is how I'm defining the method:
this.clickUploadButtonError = function () {
return uploadButton.click().thenCatch(function (err) {
throw('Cannot click upload button.');
});
};
The idea is for expect to pass by catching the error but my test still fails as uploadButton.click() throws a Selenium error:
Failed: unknown error: Element ... is not clickable at point (263, 131).
Any ideas on how can Jasmine catch the Selenium error?
You can provide an error callback explicitly:
return uploadButton.click().then(function success() {
console.log("Click was successful");
}, function failure(error) {
console.log("Click was unsuccessful");
console.log(error);
});
As a side note, if you are interested in tackling the "Element is not clickable" errors, please see this summary of the things to try.
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).