I am trying to define my mocha tests in json and then parse them and run my tests. However, I find that I am having difficulty running the tests in the callback functions
function addTwoNumbers(a,b){
return a+b;
}
function testAddNumbers(){
describe("testing the addition of 2 numbers",() => {
it('should return the addition',(done) => {
addTwoNumbers(2,2).should.be.equal(4)
done()
})
})
}
//Obtain all the test jsons
glob(__dirname +'/../**/*.doc.json', {} , (err,fileNames) => {
fileNames.forEach(fileName => {
let file = fs.readFileSync(fileName)
let tests = JSON.parse(file)
tests.forEach(test => {
testAddNumbers()
})
})
})
Which returns:
Backend listening on port 3000
0 passing (1ms)
Moving testAddNumbers() outside the glob block works, so I am not too sure of the problem. Eg:
function addTwoNumbers(a,b){
return a+b;
}
function testAddNumbers(){
describe("testing the addition of 2 numbers",() => {
it('should return the addition',(done) => {
addTwoNumbers(2,2).should.be.equal(4)
done()
})
})
}
//Obtain all the test jsons
glob(__dirname +'/../**/*.doc.json', {} , (err,fileNames) => {
fileNames.forEach(fileName => {
let file = fs.readFileSync(fileName)
let tests = JSON.parse(file)
tests.forEach(test => {
})
})
})
testAddNumbers()
returns
Backend listening on port 3000
testing the addition of 2 numbers
√ should return the addition
1 passing (238ms)
Thanks for the help!
I have fixed it in a way that I find rather disgraceful, but if you can do better do enlighten me
Problem:
Mocha was exiting when it reached the end of the file
Solution:
Loop and wait till file has completed running. This must be done within a mocha test or mocha will blatantly ignore you as if you were its mom
describe('Wait for dynamically added tests to complete', function () {
this.timeout(999999999)
it('Waiting...', function (done) {
completed = (function wait() {
// console.log(completed)
// console.log('boomdiyadah')
if (!completed) {
setTimeout(wait, 1000)
} else {
done()
}
})();
})
})
Probably this could be implemented with promises but my life needs to move forward
Related
I am having problems loading filenames into jest.each asynchronously.
My code:
let files: string[][]
function getFilesWorking() {
files = [["test1"], ["test2"]]
}
async function getFilesAsync() {
files = await Promise.resolve([["test1"], ["test2"]])
}
beforeAll(() => {
console.log("before")
})
describe.only("Name of the group", () => {
getFilesAsync()
test.each(files)("runs", f => {})
})
beforeAll is executed before each test but NOT before initialization of test.each, so I end up with undefined.
How can I load files before using test.each?
You can pass an async callback to beforeAll and await getFilesAsync within it
beforeAll(async () => {
await getFilesAsync();
})
As of Jest 28.1.3 and prior, this is not possible. There is an open issue documenting this behavior.
The best thing you can do for now is put your tests in a regular it() test and do a deep value comparison:
it('tests an array of cases', async () => {
const data = await getSomeAsyncData()
const expectedData = [ ... ]
expect(data).toEqual(expectedData)
})
You can use beforeEach to set up code that will run prior to tests for any given scope, https://jestjs.io/docs/setup-teardown:
beforeEach(() => {
console.log('before every test');
});
describe.only(('Name of the group') => {
beforeEach(() => {
console.log('before tests in this describe block');
})
})
Jest is only going to run the tests in your describe.only block. If you want to use beforeEach in other blocks and run those tests as well, change describe.only to describe.
(Edit: I know this is a year late, I'm just trying to look for a similar problem/solution set and thought I could answer this.)
I am using jest for unit testing in my node express application,please excuse , because i am new to all this
in my abc.test.js
const s3Helper = require('../../../../../lib/s3_helper');
beforeEach(async () => {
s3Helper.uploadBufferToS3 = jest.fn(() => true);
});
describe('test1', () => {
it('test1', async () => {
expect(s3Helper.uploadBufferToS3)
.toHaveBeenCalled();
});
});
describe('test2', () => {
it('test2', async () => {
expect(s3Helper.uploadBufferToS3)
.toHaveBeenCalled();
});
});
so when i run this test file in test1 it returns that test is passed, however in test2 it returns expected >=1 returned 0.
since i am mocking it beforeEach i expect it should return 1 for each describe block
I'm trying to read a csv file in my before hook but it's getting executed after the test itself for some reason.
let csvPath = path.join(__dirname, '/sample-conv.csv')
let messages = []
// read csv and push rows into an array
before(done => {
fs.createReadStream(csvPath).pipe(csv.parse({ headers: true })).on('data', row => {
messages.push(row)
}).on('end', () => {
console.log('before', messages) // this logs the full array correctly
done()
})
})
describe('Should return correct responses', () => {
let hardCoded = ['Hi', 'This is a response'] // hard codes responses to stub chatbot
console.log('after', messages) // logs empty array
it('dummy', done => {
expect(true).eq(true);
done()
})
// messages.forEach((row, i) => {
// it('Should return expected response for message #' + (i + 1), done => {
// const { send, expected } = row
// let actual = hardCoded[i]
// expect(actual).to.equal(expected)
// done()
// })
// })
})
There's also the issue that the commented out it function is not executed at all. I added the dummy test just to try to fix the before issue first. I'm assuming it's not working because of the loop.
mocha RUN CYCLE OVERVIEW
:
When a test file is loaded, Mocha executes all of its suites and finds–but does not execute–any hooks and tests therein.
Any “before all” hooks (for the root suite, this only happens once; see root hook plugins)
Every call to describe() immediately executes its callback. However, calls to it record the test for later execution. Mocha is discovering your tests while doing this but not executing them right away. At this point in time, the before hook has not been executed. That's why console.log('after', messages) logs empty array.
Simply put, the order of execution is: describe() and its callback => before hook => it()
E.g.
const { expect } = require('chai');
let messages = [];
before((done) => {
// simulate read csv operator
setTimeout(() => {
messages.push(...[1, 2, 3]);
console.log(`[${new Date().toISOString()}] before`, messages);
done();
}, 1000);
});
describe('Should return correct responses', () => {
console.log(`[${new Date().toISOString()}] after`, messages);
it('dummy', () => {
console.log(`[${new Date().toISOString()}] run dummy test case`);
expect(messages).to.be.deep.eq([1, 2, 3]);
});
});
test result:
[2020-12-25T05:31:45.066Z] after []
[2020-12-25T05:31:46.073Z] before [ 1, 2, 3 ]
Should return correct responses
[2020-12-25T05:31:46.075Z] run dummy test case
✓ dummy
1 passing (1s)
Test cases(Test1, Test2) execute before promise get the data. This is the file mockExecution.js
describe('AC 1: This is suite one', ()=>
{
before((done)=>
{
promiseResp.then((data) => {
console.log("i am in the promise");
responseData = data;
process.exit(0);
}, (err) => {
console.log('promiseResp.err', err);
process.exit(1);
})
done();
})
it('Test1', (done)=>
{
expect(responseData.measure.abc).not.toBe(responseData.measure_list.abc);
done();
});
it('Test2', (done)=>
{
expect(responseData.measure.abc).not.toBe(responseData.measure_list.abc);
done();
});
});
PromiseResp inside the Before block doesn't execute. Therefore "responseData" variable doesn't have data and it throws test case failed. I guess there is some asynchronous time issue, but don't know how to resolve it and also where do i put this "process.exit(0)". Below is the actual output:
AC 1: This is suite one
I am in the before
1) Test1
2) Test2
0 passing (7ms)
2 failing
1) AC 1: This is suite one
Test1:
TypeError: Cannot read property 'measure' of undefined
at Context.it (QA/mockExecution.js:160:29)
2) AC 1: This is suite one
Test2:
TypeError: Cannot read property 'measure' of undefined
at Context.it (QA/mockExecution.js:167:29)
[process business logic and prints some logs here, i can't paste here]
finished analyzing all records
i am in the promise
npm ERR! Test failed. See above for more details.
I am expecting output in the following sequence:
[process business logic and prints some logs here, I can't paste here]
finished analyzing all records
AC 1: This is suite one
I am in the before
I am in the promise
1) Test1 passed
2) Test2 paseed
You need to call done within your then & after you actually
assigned responseData = data:
before((done) => {
promiseResp.then((data) => {
responseData = data;
// Promise has resolved. Calling `done` to proceed to the `it` tests.
done();
})
.catch((err) => {
// Calling `done` with a truthy `err` argument, in case
// the promise fails/rejects, to fail-early the test suite.
done(err);
})
})
otherwise before ends prematurely and proceeds to the next tests, before the promise actually resolves and assigns your responseData variable.
Here's a working example using the before hook:
const expect = require('chai').expect
const getFooValue = () => {
return new Promise(resolve => {
setTimeout(() => {
resolve('foo')
}, 500)
})
}
describe('#getFooValue()', function () {
let responseData
before(done => {
getFooValue().then(data => {
responseData = data
done()
})
.catch(err => {
done(err)
})
})
it('response has a value of foo', () => {
expect(responseData).to.equal('foo');
})
it('response is a String', () => {
expect(responseData).to.be.a('String');
})
})
What you're doing now is:
You define the Promise.
You (prematurely) call done and Mocha proceeds to execute the it tests.
The it tests run while responseData is still undefined.
The Promise within before eventually resolves and assigns the responseData variable.
...but at that point it's too late. The tests have already run.
The use of done together with promises is an antipattern because this often results in incorrect control flow, like in this case. All major testing frameworks already support promises, including Mocha.
If default timeout (2 seconds) is not big enough for a promise to resolve, timeout value should be increased, e.g. as explained in this answer by setting it for current test suite (this in describe context). Notice that arrow function should be replaced with regular function to reach suite context.
It should be:
describe('AC 1: This is suite one', function () {
this.timeout(60000);
before(() => {
return promiseResp.then((data) => {
responseData = data;
});
});
it('Test1', () => {
expect(responseData.measure.abc).not.toBe(responseData.measure_list.abc);
});
...
No need for catch for a promise; promise rejections will be handled by the framework. No need for done in tests; they are synchronous.
There's no promise in your it(), so no reason for done(), but it should be called inside then() as it is a callback.
And overall it's cleaner to use async/await. It doesn't work well in before() though.
Also 'function()' is preferable in describe() to set timeout for the tests (Invoking it as a chained method never worked on my experience)
describe('AC 1: This is suite one', function() {
this.timeout(12000); //12 sec timeout for each it()
before((done) => {
promiseResp().then((data) => {
responseData = data;
done();
})
})
it('Test1', () => {
expect(responseData.measure.abc).not.toBe(responseData.measure_list.abc);
});
it('Test2', () => {
expect(responseData.measure.abc).not.toBe(responseData.measure_list.abc);
});
});
// Balance.jsx
...
updateToken () {
const parseResponse = (response) => {
if (response.ok) {
return response.json()
} else {
throw new Error('Could not retrieve access token.')
}
}
const update = (data) => {
if (data.token) {
this.data.accessTokenData = data
} else {
throw new Error('Invalid response from token api')
}
}
if (this.props.balanceEndpoint !== null) {
return fetch(this.props.accessTokenEndpoint, {
method: 'get',
credentials: 'include'
})
.then(parseResponse)
.then(update)
.catch((err) => Promise.reject(err))
}
}
componentDidMount () {
this.updateToken()
.then(() => this.updateBalance())
}
}
// Test
it('updates the balance', () => {
subject = mount(<Balance {...props} />)
expect(fetchMock.called('balance.json')).to.be.true
})
I can't figure out how to test the above using Mocha. The code is does work the method updateBalance is called and the fetch api call actually does happen, but the test still fails. If I call updateBalance() synchronously it passes... How do I tell the test to wait for the promise to resolve?
You don't really say what you want to test that the
method does, but if all you want to test is that the method resolves on a network call, then there is no need for Sinon or any of that, as this is all you need:
describe("BalanceComponent", () => {
it("should resolve the promise on a successful network call", () => {
const component = new BalanceComponent({any: 'props', foo: 'bar'});
// assumes you call a network service that returns a
// successful response of course ...
return component.updateToken();
});
});
This will test that the method actually works, but it is slow and is not a true unit test, as it relies on the network being there and that you run the tests in a browser that can supply you with a working implementation of fetch. It will fail as soon as you run it in Node or if the service is down.
If you want to test that the method actually does something specific, then you would need to to that in a function passed to then in your test:
it("should change the token on a successful network call", () => {
const component = new BalanceComponent({any: 'props', foo: 'bar'});
const oldToken = component.data.accessTokenData;
return component.updateToken().then( ()=> {
assert(oldToken !== component.data.accessTokenData);
});
});
If you want to learn how to test code like this without being reliant on there being a functioning link to the networked service you are calling, you can check out the three different techniques described in this answer.