Does jest have something like aroundEach? - jestjs

Does the testing library jest have something like aroundEach that's present in other testing libraries? I'm not sure if it's just not there or I'm searching with the wrong thing. I'm referring to something that would allow me to write code like this:
aroundEach(test => {
console.log("Printed before each test")
test() // Runs the actual test
console.log("Printed after each test")
})
For example, this is necessary to be able to write code that uses cls-hooked to run the test with a particular context. For example:
import {createNamespace} from "cls-hooked"
aroundEach(test => {
let context = createNamespace("context")
context.run(() => {
context.set("a_number", 123456)
test() // Runs the actual test
})
})
Here's an example on how to do it with Ruby MiniTest: https://github.com/jeremyevans/minitest-hooks#around-hooks-
Here's a tutorial on how it's done with Rspec in Ruby: https://spin.atomicobject.com/2013/03/24/using-the-rspec-around-hook/
In an attempt to make this work, I tried creating my own function, wrappedTest to replace (and wrap) test, like this:
function wrappedTest(name: string, fn?: ProvidesCallback, timeout?: number) {
let wrappedFn = fn
if (fn) {
wrappedFn = (done) => {
console.log("Before the test")
fn(done)
console.log("After the test")
}
}
test(name, wrappedFn, timeout)
}
and then for my test, I would just use wrappedTest instead of test:
wrappedTest("Example test", async () => {
console.log("this is the actual test")
})
Unfortunately, it fails with this error:
console.log src/entity/User.test.ts:24
Before the test
console.log src/entity/User.test.ts:33
this is the actual test
console.log src/entity/User.test.ts:26
After the test
: Timeout - Async callback was not invoked within the 5000ms timeout specified by jest.setTimeout.
I tried adding await but it made no difference:
function wrappedTest(name: string, fn?: ProvidesCallback, timeout?: number) {
let wrappedFn = fn
if (fn) {
wrappedFn = async (done) => {
console.log("Before the test")
await fn(done)
console.log("After the test")
}
}
test(name, wrappedFn, timeout)
}
If I call done in my actual test, like this:
wrappedTest("Example test", async (done) => {
console.log("this is the actual test")
done()
})
it works, but it's not necessary when I'm using test so I don't understand why it's necessary when using wrappedTest.
Oh... and this whole approach may be completely wrong anyway.

Related

Selenium Test Case not getting executed with Jest

I am working on setting up an automation test suite for an application using selenium and jest and it turns out that the console never reaches the inner body of the minimalist test case written below.
describe('When a user Opens Launchpad', () => {
test('It should be able to Navigate to Tasks Application without errors', async () => {
driver.get('http://localhost:4004/fiori.html').then(function () {
const temp = driver.findElement(By.xpath("li[#id='__tile11']"));
temp.then(function (element){
element.getAttribute("innerHTML");
expect(element.getText()).toBe("VT Dashboard");
})
});
}, 200000);
});
I looked online and tried multiple fixes like putting the driver.get() method above all these functions, making the test cases synchronous and using getText() instead of getAttribute() but none of them worked.
I either get an element not found error (The element actually exists when I check it on the chromium browser) or the test case executes successfully without reaching the expect statement in debug mode.
Bottomline is that driver.findElement() returns a promise instead of an element and would be great if I could get an element instead of promise.
Any help or correction here would be greatly appreciated.
If the function is async you should return the promise chain from that function or just use await keyword. So try following:
test('It should be able to Navigate to Tasks Application without errors', async () => {
await driver.get('http://localhost:4004/fiori.html');
const temp = await driver.findElement(By.xpath("li[#id='__tile11']"));
element.getAttribute("innerHTML");
expect(element.getText()).toBe("VT Dashboard");
}, 200000);
or
test('It should be able to Navigate to Tasks Application without errors', async () => {
return driver.get('http://localhost:4004/fiori.html').then(function () {
const temp = driver.findElement(By.xpath("li[#id='__tile11']"));
temp.then(function (element){
element.getAttribute("innerHTML");
expect(element.getText()).toBe("VT Dashboard");
})
});
}, 200000);

Can I execute a function in response to a failed assert in TestCafe?

We are using Testcafe for our regression tests and I would like to enhance the test logging of failed asserts by adding any messages from the browser console to the output. According to the Testcafe documentation, this code will print "The test has failed" in case the given element is not visible on the page:
await t.expect(Selector('#elementId').visible).ok("The test has failed");
According to the doco, the browser console messages can be read using the the t.getBrowserConsoleMessages method, but I have not been able to combine them into one statement like e.g.
await t.expect(Selector('#elementId').visible).ok(console.log(await t.getBrowserConsoleMessages()));
as this always processes the getBrowserConsoleMessages method and outputs the console messages, regardless of whether the assert is successful or not.
Is there a way to make this work only if the assert fails?
I seems you just need to call getBrowserConsoleMessages conditionally.
To get the expected behavior, you can use the following code:
import { Selector } from 'testcafe';
fixture`A set of examples that illustrate how to use TestCafe API`
.page`http://devexpress.github.io/testcafe/example/`;
test('Test1', async t => {
const isVisible = await Selector('#developer-name').visible;
if (!isVisible)
console.log(await t.getBrowserConsoleMessages())
await t.expect(isVisible).ok();
});
test('Test2', async t => {
const isVisible = await Selector('#developer-name2').visible;
if (!isVisible)
console.log(await t.getBrowserConsoleMessages())
await t.expect(isVisible).ok();
});
Here is how I got this working myself:
import { Selector } from 'testcafe';
async function objToString (obj) {
return Object.entries(obj).reduce((str, [p, val]) => {
return `${str}${p}::${val}\n`;
}, '');
}
fixture('My test')
.page('https://myurl.com')
test('Test1', async t => {
....
await t.expect(Selector('#elementId').visible).ok(await objToString(await browser.getBrowserConsoleMessages()));
....
});

How to stop jest describe without throw all the test

I want to stop a whole describe of JEST without throwing an error or stoping the other describes.
Im writing e2e test for my app with JEST and PUPPETEER, I write the test in a way every DESCRIBE its a flow of the path and every IT its a step, inside a IT I want to stop the flow if the pages dont match some conditions.
describe('Book a Room', ()=> {
it ('enter on main page' async() => await mainPage.navigateToMainPage())
it('go to book room page', async() => await bookRoomPage.navigateToBookRoomPage())
// The function its inside the "bookRoomPage"
it('check if the user can book room', () => {
if (!page.userCanOpenARoom()) {
// DONT EXECUTE THE NEXT IT BUT CONTINUE WITH THE OTHER DESCRIBE
}
})
it('go to book preview...', async() => bookRoomPreviewPage.navigateToBookRoomPreviewPage());
// REMAINING FLOW
})
I already try with process.exit(0) but exit the whole process
You can try out what this blog says here its for sharing specs in your test suites which is pretty handy. But for your case specifically you could extract your page cases in separate suites and then dynamically include the test case on runtime if a condition is met.
Something like:
Include Spec function shared_specs/index.js
const includeSpec = (sharedExampleName, args) => {
require(`./${sharedExampleName}`)(args);
};
exports.includeSpec = includeSpec;
Test A shared_specs/test_a.js
describe('some_page', () => {
it...
})
Test B shared_specs/test_b.js
describe('some_other_page', () => {
it...
})
and then in your test case
// Something like this would be your path I guess
import {includeSpec} from '../shared_specs/includeSpec.js'
describe('Book a Room', async ()=> {
if (page.userCanOpenARoom()) {
includeSpec('test_a', page);
} else {
includeSpec('test_b', page); // Or dont do anything
}
});
Just make sure that you check the paths since
require(`./${sharedExampleName}`)(args);
will load it dynamically at runtime, and use includeSpec in your describe blocks not it blocks. You should be able to split up your test suites pretty nicely with this.

How to run async functions in before hook in MochaJS?

I try to call a lot of async functions in my mocha JS before hook but they are executed at last. Basically I am trying to execute repeated tests with different params from the constructor initialization.
I tried with only one function but it also execute at last.Tried to pass done() function to inner async function but it doesnt help either.
a.test.js and base.tests.js files :
describe('Test block', () => {
before((done) => {
const baseClass = new baseClass()
baseTests.applyTests(done)
});
describe('test',()=>{
....first which should be executed;
})
}
----------------------------------------------------------------
class baseClass {
constructor() {
init smth....
}
async applyTests(done) {
await Promise.All(
[
a(),
b(),
c()
]
done();
)
}
async a() {
return describe('TEST', () => {
it('TEST', (done) => {
chai.request(server)
.get(url)
.end((err, res) => {
asserts...
done();
});
});
}}
I expect to run first the async operations in the before hook and after that all other tests.
Keep in mind that describe and it blocks do not execute any tests; they add tests to the test list that Mocha will execute. Putting a describe block inside a function called from a before hook like this won't ever end up executing code like chai.request(... etc. (And even if it did, it would be totally broken: a before hook is run before each test, you don't want to do asserts there because it won't be linked to any particular unit test.)
I can't give more concrete advice because I'm not sure what you were trying to accomplish, but in general, your describe and it blocks should be top-level constructs and not put inside other code like this.
EDIT: Just to make the execution path here clear: your before hook runs, which calls applyTests, which calls a(), which executes a describe block and adds your unit test TEST to the test list, then it returns. It then begins running tests, including test and TEST.
EDIT: Ah, makes sense, let me suggest two patterns that are often used in unit tests.
Pattern 1: "Test Loop"
This pattern creates many similar-looking tests, using an array of input params to produce appropriate test descriptions and test bodies.
[
{ foo: "milk", bar: "smoothie" },
{ foo: "yogurt", bar: "fridge" },
{ foo: "whatever", bar: "container" }
].forEach(test => {
it("puts the " + test.foo + " in the " + test.bar, function () {
assert(subject.someMethod(foo) === bar);
});
});
Pattern 2: "Test Helper"
This pattern creates individual tests, but puts a common test body in a helper method so it can be reused.
function testSomeMethod(foo, bar) {
assert(subject(foo) == "bar");
}
it("puts the milk in the fridge", function () {
testSomeMethod("milk", "fridge");
});
it("puts the cereal in the pantry", function () {
testSomeMethod("cereal", "pantry");
});
Examples above are very simple, but either the test loop or the test helper pattern can be used to encapsulate a much more complicated series of steps (set up a request, look at some response headers / bodies, etc.).

How can I build my test suite asynchronously?

I'm trying to create mocha tests for my controllers using a config that has to be loaded async. Below is my code. However, when the mocha test is run, it doesn't run any tests, displaying 0 passing. The console.logs are never even called. I tried doing before(next => config.build().then(next)) inside of the describe, but even though the tests run, before is never called. Is there a way to have the config be loaded one time before any tests are run?
'use strict';
const common = require('./common');
const config = require('../config');
config
.build()
.then(test);
function test() {
console.log(1);
describe('Unit Testing', () => {
console.log(2);
require('./auth');
});
}
You should run Mocha with the --delay option, and then use run() once you are done building your test suite. Here is an example derived from the code you show in the question:
'use strict';
function test() {
console.log(1);
describe('Unit Testing', () => {
console.log(2);
it("test", () => {
console.log(3);
});
});
// You must use --delay for `run()` to be available to you.
run();
}
setTimeout(test, 1000);
I'm using setTimeout to simulate an asynchronous operation. Using --delay and run() allows you to build a suite that is the result of an asynchronous computation. Note, however, that the suite must be built in one shot. (You cannot have an asynchronous process inside describe that will make calls to it. This won't work.)
One thing you should definitely not do is what rob3c suggests: calling describe or it (or both) from inside a hook. This is a mistake that every now and then people make so it is worth addressing in details. The problem is that it is just not supported by Mocha, and therefore there are no established semantics associated with calling describe or it from inside a hook. Oh, it is possible to write simple examples that work as one might expect but:
When the suite becomes more complex, the suite's behavior no longer corresponds to anything sensible.
Since there are no semantics associated with this approach, newer Mocha releases may handle the erroneous usage differently and break your suite.
Consider this simple example:
const assert = require("assert");
const p = Promise.resolve(["foo", "bar", "baz"]);
describe("top", () => {
let flag;
before(() => {
flag = true;
return p.then((names) => {
describe("embedded", () => {
for (const name of names) {
it(name, () => {
assert(flag);
});
}
});
});
});
after(() => {
flag = false;
});
it("regular test", () => {
assert(flag);
});
});
When we run it, we get:
top
✓ regular test
embedded
1) foo
2) bar
3) baz
1 passing (32ms)
3 failing
// [stack traces omitted for brevity]
What's going on here? Shouldn't all the tests pass? We set flag to true in the before hook for the top describe. All tests we create in it should see flag as true, no? The clue is in the output above: when we create tests inside a hook, Mocha will put the tests somewhere but it may not be in a location that reflects the structure of the describe blocks in the code. What happens in this case is that Mocha just appends the tests created in the hook the the very end of the suite, outside the top describe, so the after hook runs before the dynamically created tests, and we get a counter-intuitive result.
Using --delay and run(), we can write a suite that behaves in a way concordant with intuition:
const assert = require("assert");
const p = Promise.resolve(["foo", "bar", "baz"]).then((names) => {
describe("top", () => {
let flag;
before(() => {
flag = true;
});
after(() => {
flag = false;
});
describe("embedded", () => {
for (const name of names) {
it(name, () => {
assert(flag);
});
}
});
it("regular test", () => {
assert(flag);
});
});
run();
});
Output:
top
✓ regular test
embedded
✓ foo
✓ bar
✓ baz
4 passing (19ms)
In modern environments, you can use top-level await to fetch your data up front. This is a documented approach for mocha: https://mochajs.org/#dynamically-generating-tests
Slightly adapting the example from the mocha docs to show the general idea:
function fetchData() {
return new Promise((resolve) => setTimeout(resolve, 5000, [1, 2, 3]));
}
// top-level await: Node >= v14.8.0 with ESM test file
const data = await fetchData();
describe("dynamic tests", function () {
data.forEach((value) => {
it(`can use async data: ${value}`, function () {
// do something with data here
});
});
});
This is nice as it is on a per-file basis, and doesn't involve you taking on management responsibility of the test runner as you do with --delay.
The problem with using the --delay command line flag and run() callback that #Louis mentioned in his accepted answer, is that run() is a single global hook that delays the root test suite. Therefore, you have to build them all at once (as he mentioned), which can make organizing tests a hassle (to say the least).
However, I prefer to avoid magic flags whenever possible, and I certainly don't want to have to manage my entire test suite in a single global run() callback. Fortunately, there's a way to dynamically create the tests on a per-file basis, and it doesn't require any special flags, either :-)
To dynamically create It() tests in any test source file using data obtained asynchronously, you can (ab)use the before() hook with a placeholder It() test to ensure mocha waits until before() is run. Here's the example from my answer to a related question, for convenience:
before(function () {
console.log('Let the abuse begin...');
return promiseFn().
then(function (testSuite) {
describe('here are some dynamic It() tests', function () {
testSuite.specs.forEach(function (spec) {
it(spec.description, function () {
var actualResult = runMyTest(spec);
assert.equal(actualResult, spec.expectedResult);
});
});
});
});
});
it('This is a required placeholder to allow before() to work', function () {
console.log('Mocha should not require this hack IMHO');
});

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