I have searched online but I didn't find a way to mock window.close() in react testing library or even in jest.
const handleClose = () => {
window.opener.location.reload()
window.close()
}
<Button
data-test-id="close"
onClick={handleClose}
/>
How do I achieve test case coverage for the onclick of button and window.close() and window.opener.location.reload() is covered
My test case is as follows:
const wrapper = render( <CloseButton />);
const windowSpy = jest.spyOn(global, 'window', 'get');
const { queryByTestId } = wrapper;
fireEvent.click(queryByTestId('close');
expect(windowSpy.opener.location.relaod).toHaveBeenCalled();
expect(windowSpy.close).toHaveBeenCalled();
for this last line of code
expect(windowSpy.close).toHaveBeenCalled();
I am getting an error that says
received value must be a mock or spy function. received has value
undefined
For
expect(windowSpy.opener.location.relaod).toHaveBeenCalled();
it says:
windowSpy.opener is not defined.
You're only mocking window but you're not providing any implementation.
This should help:
windowSpy.mockImplementation(() => ({
close: jest.fn(),
opener: {
location: {
reload: jest.fn(),
}
}
}));
If you don't actually need a spy, just a mock, I've had luck with simply reassigning the particular window function:
global.window.opener.location.reload = jest.fn()
Remarkable Mark provides a solution to this that avoids all the above pitfalls, as well as the reload is not declared configurable error that you may get when you try to modify reload() directly. See:
https://remarkablemark.org/blog/2018/11/17/mock-window-location/
Code is copied here directly from this ^ page:
describe('window.location', () => {
const { location } = window;
beforeAll(() => {
delete window.location;
window.location = { reload: jest.fn() };
});
afterAll(() => {
window.location = location;
});
it('mocks `reload`', () => {
expect(jest.isMockFunction(window.location.reload)).toBe(true);
});
it('calls `reload`', () => {
window.location.reload();
expect(window.location.reload).toHaveBeenCalled();
});
});
Thanks Mark!
https://remarkablemark.org/support/
Related
I have a function that I have mocked in my test cases file.
MyService.getConfigsForEntity = jest.fn().mockReturnValue(
new Promise(resolve => {
let response = [];
resolve(response);
})
);
Now I want all my test cases in that file to use this mock like
describe('Should render Component Page', () => {
it('should call the API', async () => {
const {container} = render(<MyComp entityName='entity1'/>);
await wait(() => expect(MyService.getConfigsForEntity).toHaveBeenCalled());
});
});
The only issue is in only one of the test case I want to mock the return value differently.
But all other test cases before and after can use the global mock.
describe('Should call API on link click', () => {
it('should call the API on link click', async () => {
const spy = jest.spyOn(MyService, 'getConfigsForEntity ').mockReturnValue(
new Promise(resolve => {
let response = [{
"itemName": "Dummy"
}];
resolve(response);
});
const {container} = render(<MyComp entityName='entity1'/>);
await wait(() => expect(spy).toHaveBeenCalled());
spy.mockClear();
});
});
The problem is , once I mock the function differently inside one test case , all other test cases after that test case, that are using the global mock , are failing,
But it only works if I put the test case after all other test cases.
What am I doing wrong?
You can try with mockRestore():
beforeEach(() => {
spy.mockRestore();
});
have you tried?
beforeEach(() => {
jest.clearAllMocks();
})
I have a component which has a form with a submit button which when clicked performs an axios.put which I want to intercept and test.
So far I have the following code simplified for this example:
describe('Edit Client functionality', () => {
beforeEach(() => {
const mock = new MockAdapter(axios);
mock
.onPut('http://localhost:5000/api/entity/client/1')
.reply(200, { success: true });
});
it('Dummy example test', done => {
const component = mount(<DummyComponent />);
const spy = jest.spyOn(axios, 'put');
component.find('form').simulate('submit')
setTimeout(() => {
expect(spy).toHaveBeenCalled();
done();
}, 0);
})
I've tried many variations of the above but can't get the mocked PUT to be called. Any suggestions appreciated.
I am testing a functional component that has a submit button that makes an async call to an api. The async call is located within a custom hook. As per standard testing practices, I have mocked the hook, so that my mock will be called instead of the actual async api:
someComponent.test.js
jest.mock("../../../CustomHooks/user", () => ({
useUser: () => ({
error: null,
loading: false,
forgotPassword: <SOMETHING HERE>
})
}));
I know that my forgotPassword function is called because when I change it to forgotPassword: "", I get an error in my test stating that forgotPassword is not a function.
A very simple representation of the function that is called when my submit button is clicked is this:
someComponent.js
import { useUser } from "../../../CustomHooks/user"
const SomeComponent = () => {
....state and other things etc....
const { error, loading, forgotPassword } = useUser()
const submit = async () => {
await forgotPassword(emailValue);
setState(prevState => {
return {
...prevState,
content: "code"
};
});
}
}
NOTE: My call to the async function await forgotPassword... is wrapped in a try/catch block in my code, but I have left this out for clarity.
In production, when the submit button is pressed, the async call occurs, and then the state should be switched, thus rendering some other components. My test looks to see if these components have been rendered (I am using react testing library for this).
The problem that I am having is that no matter what I place in the placeholder of the first code block, my test will always fail as the setState block is never reached. If I remove the await statement, then the setState block is hit and the component that I want to appear is there as the state has changed. However, obviously this will not work as intended outside of the test as the actual call is asynchronous. Here are some of the approaches that I have tried that do not work:
DOESN'T WORK
forgotPassword: () => {
return Promise.resolve({ data: {} });
}
DOESN'T WORK
forgotPassword: jest.fn(() => {
return Promise.resolve();
})
DOESN'T WORK
forgotPassword: jest.fn(email => {
return new Promise((resolve, reject) => {
if (email) {
resolve(email);
} else {
reject("Error");
}
});
}),
As I have said already, if I remove the await statement, then the state changes and the component appears, and hence the test passes. However, for obvious reasons, this is not what I want.
Extra Info
Here is a simplified version of my test:
it("changes state/content from email to code when submit clicked", () => {
const { getByTestId, getByText, debug } = render(<RENDER THE COMPONENT>);
const submitButton = getByTestId("fpwSubmitButton");
expect(submitButton).toBeInTheDocument();
const emailInput = getByTestId("fpwEmailInput");
fireEvent.change(emailInput, {
target: { value: "testemail#testemail.com" }
});
fireEvent.click(submitButton);
debug();
THE STATEMENTS BELOW ARE WHERE IT FAILS AS THE STATE DOESN'T CHANGE WHEN AWAIT IS PRESENT
const codeInput = getByTestId("CodeInput");
expect(codeInput).toBeInTheDocument();
});
To anyone who encounters this same problem, I found three ways that this can be solved (the preferred method is Option 3). All methods use a simple mock function that replaces the <SOMETHING HERE> of the first code block in my question. This can be replaced with () => {}:
jest.mock("../../../CustomHooks/user", () => ({
useUser: () => ({
error: null,
loading: false,
forgotPassword: () => {}
})
}));
Option 1
The first approach is to wrap your test code that relies on an async function in a setTimeout with a done callback:
it("changes state/content from email to code when submit clicked", done => {
const { getByTestId, debug } = render(<RENDER THE COMPONENT>);
const submitButton = getByTestId("fpwSubmitButton");
expect(submitButton).toBeInTheDocument();
const emailInput = getByTestId("fpwEmailInput");
fireEvent.change(emailInput, {
target: { value: "testemail#testemail.com" }
});
fireEvent.click(submitButton);
setTimeout(() => {
const codeInput = getByTestId("CodeInput");
expect(codeInput).toBeInTheDocument();
done();
});
debug();
});
Notice on the top line the done call back, as well as the test code wrapped in setTimeout at the bottom, and then invoking the callback within the setTimeout to tell jest that the test is done. If you don't call the done callback, the test will fail as it will timeout.
Option 2
The second approach is to use a function called flushPromises():
function flushPromises() {
return new Promise(resolve => setImmediate(resolve));
}
it("changes state/content from email to code when submit clicked", async () => {
const { getByTestId, debug } = render(<RENDER THE COMPONENT>);
const submitButton = getByTestId("fpwSubmitButton");
expect(submitButton).toBeInTheDocument();
const emailInput = getByTestId("fpwEmailInput");
fireEvent.change(emailInput, {
target: { value: "testemail#testemail.com" }
});
fireEvent.click(submitButton);
await flushPromises();
const codeInput = getByTestId("CodeInput");
expect(codeInput).toBeInTheDocument();
debug();
});
Notice the flushPromises() function at the top, and then the call site towards the bottom.
Option 3 (Preferred Method)
The final method is to import wait from react-testing-library, set your test as asynchronous and then await wait() whenever you have async code:
...
import { render, fireEvent, cleanup, wait } from "#testing-library/react";
...
it("changes state/content from email to code when submit clicked", async () => {
const { getByTestId, debug } = render(<RENDER THE COMPONENT>);
const submitButton = getByTestId("fpwSubmitButton");
expect(submitButton).toBeInTheDocument();
const emailInput = getByTestId("fpwEmailInput");
fireEvent.change(emailInput, {
target: { value: "testemail#testemail.com" }
});
fireEvent.click(submitButton);
await wait()
const codeInput = getByTestId("CodeInput");
expect(codeInput).toBeInTheDocument();
debug();
});
All of these solutions work because they wait for the next event loop before executing the test code. Wait() is basically a wrapper around flushPromises() with the added benefit of including act(), which will help to silence test warnings.
try something like this
forgotPassword: jest.fn( async email => {
return await new Promise( ( resolve, reject ) => {
if ( email ) {
resolve( email );
} else {
reject( "Error" );
}
} );
} );
If it doesn't work let me know.
Code
import { createUser } from '../services';
...
...
handleFormSubmit = () => {
this.setState({ loading: true });
createUser()
.then(() => {
this.setState({
loading: false,
});
})
.catch(e => {
this.setState({
error: e,
});
});
};
Test
it('rejects...', () => {
const Container = createUserContainer(CreateUser);
const wrapper = shallow(<Container />);
return wrapper.instance().handleFormSubmit()
.catch(e => {
console.log("State: ", wrapper.state());
expect(e).toEqual('error');
});
});
Mock
export const createUser = function() {
return new Promise((resolve, reject) => {
reject('error');
});
};
The test does force the code to go into the catch in the method. So the state does get set to 'error'.
But in my test, it doesn't do what I expect and wait for the Promise to reject before it tests for the state change.
I'm not sure what to try here, should I be using async/await?
So it's the createUser method I want to wait for but I'm not sure my implementation allows for this.
You should do something like this:
it('rejects...', () => {
const Container = createUserContainer(CreateUser);
const wrapper = shallow(<Container />);
return expect(wrapper.instance().handleFormSubmit()).rejects.toEqual('error');
});
I think it is cleaner this way. You can see this approach in the official docs.
It's important to note that .rejects (and .resolves) returns a promise, which is returned in the example above so that jest knows to wait on it. If you don't return it, you MUST await it:
it('rejects...', async () => {
const Container = createUserContainer(CreateUser);
const wrapper = shallow(<Container />);
await expect(wrapper.instance().handleFormSubmit()).rejects.toEqual('error');
});
The test fails because it's not aware that the subject is asynchronous. It can be fixed by using a done param or making the test function async.
Note it's also necessary to set the number of expected assertions so that the test will fail even if the catch branch is not taken.
async/await style:
it('rejects...', async () => {
expect.assertions(1);
const Container = createUserContainer(CreateUser);
const wrapper = shallow(<Container />);
await wrapper.instance().handleFormSubmit()
.catch(e => {
console.log("State: ", wrapper.state());
expect(e).toEqual('error');
});
});
Older style done param:
it('rejects...', done => {
expect.assertions(1);
const Container = createUserContainer(CreateUser);
const wrapper = shallow(<Container />);
wrapper.instance().handleFormSubmit()
.catch(e => {
console.log("State: ", wrapper.state());
expect(e).toEqual('error');
done();
});
});
Asynchronous Testing Reference
expect.assertions reference
Your code looks correct. Why do you say that it doesn't wait for the Promise to reject? The only difference I would make would be to make use of Jest's mocking capability, so change
Mock
export const createUser = function() {
return new Promise((resolve, reject) => {
reject('error');
});
};
to
Test
jest.mock('../services');
const services = require('../services');
const createUser = jest.spyOn(services, "createUser");
createUser.mockRejectedValue("error");
...
it('rejects...', () => {
There's no need to have a separate Mock file
In your code handleFormSubmit function should return Promise on which you can wait in your test. Also you need to return truthful data from success and error callback to resolve and reject the promise respectively.
handleFormSubmit = () => {
this.setState({ loading: true });
return createUser()
.then(() => {
this.setState({
loading: false,
});
return true;
})
.catch(e => {
this.setState({
error: e,
});
throw e;
});
};
Here in your actual code you have caught the error in catch handler and trying to catch it further in out test case code. Hence catch can not be chained further, while you can chain then multiple times.
For reference go through Promise documentations:
https://www.peterbe.com/plog/chainable-catches-in-a-promise
In my component I have ...
onSubmit = (e) => {
e.preventDefault();
const { history, versionStore } = this.props;
versionStore.add(this.state.formData)
.then(() => history.push('/'));
}
On my test...
it('after successfully submit should redirect to / page', () => {
const spy = jest.spyOn(minProps.history, 'push')
.mockImplementation((path) => {
console.log('called with ', path); // IS CALLED!
});
const wrapper = shallow(<Add.wrappedComponent {...minProps} />);
fetchMock.postOnce('/api/version', { name: 'v1' });
wrapper.setState({ formData: { name: 'v1' } });
wrapper.find('form').simulate('submit', { preventDefault: jest.fn() });
expect(spy).toHaveBeenCalledWith('/');
spy.mockReset();
spy.mockRestore();
});
The test fail with
called with /
expect(jest.fn()).toHaveBeenCalledWith(expected)
Expected mock function to have been called with: ["/"]
But it was not called.
your redirect is inside of asynchronous code and you are testing it in a synchronous manner, meaning when the test executes the promise is not resolved yet. I would tackle this in one of 2 ways
1 - test your submit function w/o the event, then you can return the promise and test the redirection after the promise chain is successful
2 - mock versionStore.add to be synchronous and immidattly execute it's then function.