I have a module that looks like this:
const config = require('config')
const isActive = config.get('isActive')
const infoMap = new Map()
const set = (key, value) => {
infoMap.set(key, value)
}
const get = (key) => infoMap.get(key)
module.exports={set, get}
and a test where I test the stuff:
let get
let set
beforeEach(() => {
jest.mock('config')
mockIsActive = require('config').get.mockReturnValueOnce(true)
get = require('../cache/mymap').get
set = require('../cache/mymap').set
})
describe('The map', () => {
describe('when data is added', () => {
set('testKey', "testData")
it('should contains the data', async () => {
const dataFromMap = get('testKey')
assert("testData", dataFromMap)
})
})
})
It fails when the set is called with:
set is not a function
Strange is that get works without problems.
You must call the set function inside the it function, otherwise it is not yet defined:
describe('when data is added', () => {
it('should contains the data', async () => {
set('testKey', "testData")
const dataFromMap = get('testKey')
assert("testData", dataFromMap)
})
})
beforeEach runs before each it function, not before describe. This is also why get does work in your example - it is inside the it function.
Related
im using an http request function as the handler function in middy and then use the ssm middleware to fetch some ssm parameters before initiating the http request.
like this:
const makeThirdPartyServiceRequest = middy(async ({ params }) => {
logger.info(`SENDING Request to ${endpoint} API`)
const url = `https://someurltoathirdpartyservice`
const options = {
method: 'POST',
body: params
}
return helpers.makeRequest(url, options)
})
makeThirdPartyServiceRequest.use(ssm(......))
However in my jest unit test Im trying to mock makeThirdPartyServiceRequest and explicitly say it should resolve to a value:
jest.mock('../src/thirdPartyService', () => ({
__esModule: true,
default: {
...(jest.requireActual('../src/thirdPartyService') as { default: {} }).default,
makeThirdPartyServiceRequest: jest.fn()
}
}))
export {}
import thirdPartyService from '../src/thirdPartyService'
And then in the test i say:
describe('makeThirdPartyServiceRequest()', () => {
it('should makeThirdPartyServiceRequest', async () => {
// Given
// })
const mockedThirdPartyServiceRequest = mocked(thirdPartyService.makeThirdPartyServiceRequest).mockResolvedValue({})
// When
const result = await thirdPartyService.makeThirdPartyServiceRequest(something)
// Then
expect(mockedThirdPartyServiceRequest).toHaveBeenCalledTimes(1)
expect(mockedThirdPartyServiceRequest.mock.calls[0][0].params.toString()).toBe(expectedParams)
})
})
However for some reason the middy middleware is still being invoked, which i clearly dont want and i have tried to mock away... what am i doing wrong?
You need to mock middy instead, to make it becomes a useless function. That function recipe a function as a parameter and return that parameter.
import thirdPartyService from '../src/thirdPartyService'
jest.mock('#middy/core', () => {
return (handler) => {
return {
use: jest.fn().mockReturnValue(handler), // ...use(ssm()) will return handler function
}
}
})
describe('thirdPartyService()', () => {
beforeEach(() => {
jest.spyOn(helpers, 'makeRequest') // spy on helpers unit
})
describe('makeThirdPartyServiceRequest', () => {
it('should make a request with correct parameters', async () => {
// Given
const url = `https://someurltoathirdpartyservice`
const params = 'any params'
const apiResponse = 'any response'
mocked(helpers.makeRequest).mockResolvedValue(apiResponse)
// When
const actual = await thirdPartyService.makeThirdPartyServiceRequest(params)
// Then
expect(actual).toBe(apiResponse)
expect(helpers.makeRequest).toHaveBeenCalledWith(
url,
{
method: 'POST',
body: params
}
)
})
})
})
hoangdv answer is also valid, but i will answer as well how i continued.
if you completely want to mock middy you mock like following:
jest.mock('#middy/core', () => {
return (handler) => {
return {
use: jest.fn().mockImplementation(() => {
// ...use(ssm()) will return handler function
return {
before: jest.fn().mockReturnValue(handler)
}
})
}
}
})
However if you dont want to completely mock middy, you can instead mock the async getInternal function from middy/util called in before like this:
jest.doMock('#middy/util', () => ({
...(jest.requireActual('#middy/util') as {}),
getInternal: jest.fn()
}))
import { getInternal } from '#middy/util'
and then in the test
describe('thirdPartyService()', () => {
beforeEach(() => {
jest.spyOn(helpers, 'makeRequest') // spy on helpers unit
})
describe('makeThirdPartyServiceRequest', () => {
it('should make a request with correct parameters', async () => {
// Given
const url = `https://someurltoathirdpartyservice`
const params = 'any params'
const apiResponse = 'any response'
mocked(getInternal).mockResolvedValue({
twilioSecrets: { accountSid: 'someSID', serviceId:
'someServiceID', token: 'someToken' }
})
mocked(helpers.makeRequest).mockResolvedValue(apiResponse)
// When
const actual = await thirdPartyService.makeThirdPartyServiceRequest(params)
// Then
expect(actual).toBe(apiResponse)
expect(helpers.makeRequest).toHaveBeenCalledWith(
url,
{
method: 'POST',
body: params
}
)
})
})
})
this will mock the async part of middy.
I am trying to test my service which have one function saveWithoutSubmit
export const saveWithoutSubmit = async (
values,
orderId,
taskId,
fseMsisdn,
updateTaskListAfterFilter
) => {
var obj = {
remarks: values.remarks,
requestedBy: localStorage.getItem("msisdn")
};
try {
const response = await sendPostRequest(`${API_TASK_URL}closeSr`, {
...obj,
saveWithoutSubmit: true
});
if (response && response.data && response.data.status.code !== "200") {
error(response.data.result.message);
} else {
console.log(response);
success(response.data.status.message);
updateTaskListAfterFilter();
}
} catch (e) {
if (e.response && e.response.data) {
console.log(e.response.data.message);
error(e.response.data.status.message);
}
}
};
I want to check success or error method is called or not ? or updateTaskListAfterFilter is called or not?
I tried like this
https://codesandbox.io/s/ecstatic-currying-5q1b8
describe("remark service test", () => {
const fakeAxios = {
get: jest.fn(() => Promise.resolve({ data: { greeting: "hello there" } }))
};
it("save without sumit", () => {
const updateTaskListAfterFilter = () => {};
saveWithoutSubmit({}, updateTaskListAfterFilter);
expect(updateTaskListAfterFilter).toBeCalled();
});
});
can you please suggest how i will test async methods or post request (using mook data)??
so that my test cases will be passed.
I want to check if I got success from promise my success method will be called else error
any update ?..!!
update
https://codesandbox.io/s/ecstatic-currying-5q1b8
it("save without sumit", async () => {
const sendPostRequest = jest.fn(() =>
Promise.resolve({ data: { greeting: "hello there" } })
);
const updateTaskListAfterFilter = () => {};
saveWithoutSubmit({}, updateTaskListAfterFilter);
expect(updateTaskListAfterFilter).toBeCalled();
});
it("save without sumit", async () => {
const sendPostRequest = jest.fn(() =>
Promise.resolve({ data: { greeting: "hello there" } })
);
const mockUpdateTaskListAfterFilter = jest.fn();
const updateTaskListAfterFilter = () => {};
saveWithoutSubmit({}, updateTaskListAfterFilter);
expect(updateTaskListAfterFilter).toBeCalled();
await wait(() => {
expect(mockUpdateTaskListAfterFilter).toBeCalled();
});
});
You should change it("save without sumit", () => { to it("save without sumit", async () => {.
Then you usually use jest.fn() to create a mock function that you will give to another function or component.
Finally, await the mock function to be called:
await wait(() => {
expect(mockUpdateTaskListAfterFilter).toBeCalled();
});
Alternatively, you can await some other event that you know will occur before your mock is called, like some other mock getting called or something appearing on the page, and then check that your mock was called.
In our node CLI we have a simple method:
'use strict';
const ora = require('ora');
module.exports = function startSpinner({ textOnStart, color, spinnerType }) {
const spinner = ora({
text: textOnStart,
color: color || 'cyan',
spinner: spinnerType || ''
}).start();
};
We try to use jest to test this method. We have two tests to achieve:
Testing that ora has been called with proper object argument
Testing that the method start() was called afterward
That being said we cannot achieve to mock ora module properly.
ora is a third party that is basically constructed as follow:
class Ora {
constructor(options){}
start(){ }
}
const oraFactory = function (opts) {
return new Ora(opts);
};
module.exports = oraFactory;
module.exports.default = oraFactory;
We are looking for a way to mock ora.
We tried to use auto mock:
const ora = require('ora');
jest.mock('ora');
const startSpinner = require('./startSpinner');
describe('startSpinner', () => {
beforeEach(() => {
startSpinner({});
});
describe('ora', () => {
it('should call ora', () => {
expect(ora).toHaveBeenCalled();
});
it('should call ora start', () => {
expect(ora.start).toHaveBeenCalled();
});
});
});
But both tests fail with respectively:
Matcher error: received value must be a mock or spy function
Received has type: function
Received has value: [Function oraFactory]
and
Matcher error: received value must be a mock or spy function
Received has value: undefined
We tried to use a custom mock:
const ora = require('ora');
jest.mock('ora', () => {
return jest.fn().mockImplementation(() => {
return { start: jest.fn() };
});
});
and it ends up with the same exact result.
We even tried to convert our test to typescript and then use:
import * as ora from 'ora';
const startMock = jest.fn();
jest.mock('ora', () => {
return jest.fn().mockImplementation(() => {
return { start: startMock };
});
});
Then we were able to test successfuly that ora was called. But we ended up with an error for expect(ora.start).toHaveBeenCalled(); or even expect((ora as any).start).toHaveBeenCalled();:
error TS2339: Property 'start' does not exist on type 'typeof
import("/Users/Dev/cli/node_modules/ora/index")'.
Surely caused by the fact the type definition of imported ora is export default function ora(options?: Options | string): Ora;
How to then mock a third party like ora in jest's node test environnement?
You've got a couple of options:
You can mock ora like this:
jest.mock('ora', () => {
const start = jest.fn();
const result = { start };
return jest.fn(() => result);
});
...and then call ora to get the object it returns (since it always returns the same object) and use that object to access start:
it('should call ora start', () => {
const result = ora();
expect(result.start).toHaveBeenCalled(); // Success!
});
Or if you want you can attach the start mock as a property to the ora mock as an easy way to access it during your tests like this:
const ora = require('ora');
jest.mock('ora', () => {
const start = jest.fn();
const result = { start };
const ora = jest.fn(() => result);
ora.start = start; // attach the start mock to ora
return ora;
});
const startSpinner = require('./startSpinner');
describe('startSpinner', () => {
beforeEach(() => {
startSpinner({});
});
describe('ora', () => {
it('should call ora', () => {
expect(ora).toHaveBeenCalled(); // Success!
});
it('should call ora start', () => {
expect(ora.start).toHaveBeenCalled(); // Success!
});
});
});
I stub getElementById in beforeEach, and want to restore it before another test and stub again with anothter returns value. Because now I recieve error
TypeError: Attempted to wrap getElementById which is already wrapped
let loginUrl = 'loginUrl'
const url = '/app/auth'
const textContent = `{"${loginUrl}":"${url}"}`
let htmlDecode
describe('identityServer', () => {
beforeEach(() => {
htmlDecode = sinon.stub().returns(textContent)
sinon.stub(document, 'getElementById').returns({textContent})
sinon.stub(htmlEncoder, 'Encoder').returns({htmlDecode: () => htmlDecode})
identityServerModel()
})
it('should return correct model for IdentityServer', () => {
window.identityServer.getModel().should.deep.equal({[loginUrl]: url})
})
})
describe('identityServer', () => {
beforeEach(() => {
htmlDecode = sinon.stub().returns(textContent)
sinon.stub(document, 'getElementById').returns({innerHTML: textContent})
sinon.stub(htmlEncoder, 'Encoder').returns({htmlDecode: () => htmlDecode})
identityServerModel()
})
it('should return correct model using serialization HTML from innerHTML property when textContent is undefined', () => {
window.identityServer.getModel().should.deep.equal({[loginUrl]: url})
})
})
Try add:
afterEach(() => {
document.getElementById.restore();
})
into every describe(...).
I have a test where I'm trying to mock a component in two different situations. When I use jest.fn. It almost looks like the first test is just taking the value from the second.
describe('tests', () => {
let sampleArray = new Array()
Array.prototype.test = function() {
return this.innerArray()
}
describe('empty', () => {
sampleArray.innerArray = jest.fn(() => [])
it('testArray is empty', () => {
expect(sampleArray.test().length).toEqual(0)
})
})
describe('not empty', () => {
sampleArray.innerArray = jest.fn(() => ['test'])
it('testArray is not empty', () => {
console.log(sampleArray.innerArray())
expect(sampleArray.test().length).toEqual(1)
})
})
})
When I console.log I get the array I expect from innerArray, but it just looks like it doesn't use it.
FAIL test/sample.test.js
tests
empty
✕ testArray is empty (8ms)
not empty
✓ testArray is not empty (4ms)
● tests › empty › testArray is empty
expect(received).toEqual(expected)
Expected value to equal:
0
Received:
1
edit: If I place it inside the it scope, it works. But why can't I do it in the describe scope?
describe('tests', () => {
let sampleArray = new Array()
Array.prototype.test = function() {
return this.innerArray()
}
describe('empty', () => {
it('testArray is empty', () => {
sampleArray.innerArray = jest.fn(() => [])
console.log(sampleArray.innerArray())
expect(sampleArray.test().length).toEqual(0)
})
})
describe('not empty', () => {
it('testArray is not empty', () => {
sampleArray.innerArray = jest.fn(() => ['test'])
expect(sampleArray.test().length).toEqual(1)
})
})//works
Unless you specifically expect the array to be shared among all your tests, you should set it up as follows:
Array.prototype.test = function() {
return this.innerArray()
}
describe('tests', () => {
let sampleArray
beforeEach(() =>
sampleArray = new Array()
})
// tests...
});