So I have this function inside my Vue Component:
function openLink(event: Event, url: string, type: string) {
switch (type) {
case 'onetype':
case 'twotype':
event.preventDefault()
openURLInBrowser(url, '_blank');
break
}
}
I am writing my unit test with Vitest. I can easily test, if openLink have been called:
const wrapper = shallowMount(MyLinks, {
propsData: {
myLinks: linkDataStructure
}
})
const a = wrapper.find('a');
const openLink= vi.spyOn(wrapper.vm, 'openLink')
await a.trigger('click');
expect(openLink).toHaveBeenCalled()
This works great. Now I need to test the case, if type is onetype, the method openURLInBrowser is called. So basically the switchcase inside the openLink function.
If I use following, I get: openURLInBrowser does not exist.
const openLink= vi.spyOn(wrapper.vm, 'openURLInBrowser')
How can I access this method inside the function to test it?
Note: The function openURLInBrowser is imported from a openURLInBrowser.ts-File.
Related
I am triggering a function when the route is changed in watch property
I used wrapper.vm.$options.watch.$route.call(wrapper.vm,'test1','test2)
It shows error wrapper.vm.$options.watch.$route.call is not a function
can someone please tell me what i'm missing
This is my code:
js file:
watch: {
$route() {
this.eventSearchQueryHandler()
console.log("hebdhdb")
},
jest file:
test('watch: $route', () => {
const wrapper = getWrapper()
const spy = jest.spyOn(wrapper.vm, 'eventSearchQueryHandler')
wrapper.vm.$options.watch.$route.call(wrapper.vm, '/tivo/deals')
expect(spy).toBeCalled()
})
I want to mock the watcher and check the function to be called.
Is there any other approach that i can trigger this watch and test the function to be called
I have created a custom hook that returns the translated value using the useTranslation hook.
import { useTranslation } from "next-i18next";
export const useCustomHook = (data) => {
const {t, i18n: { language: locale }} = useTranslation();
const value = {
field: t("some.key.from.json.file", { arg: data.arg }),
field2: data.name,
field3: t("another.key", {
arg: data.arg2, count: 3
})
}
return value;
};
I want to create a unit test for this custom hook, but I can't get the useTranslation hook to work as it does when running the app itself. Further info my current setup is as follows:
1- I'm using Nextjs with next-i18next library.
2- No i18n provider to wrap the app, only using HOC from next-i18next to wrap _app.
3- I have 2 json files for locales.
Is there a way to allow the useTranslation hook to work and get the parsed value from the translation file? here's what I tried so far too:
1- mocking the useTranslation hook, but this returns the ("another.key") as is without the parsed value.
2- I tried to create a wrapper with i18n-next provider, but that didn't work too.
Here's my test file.
describe("useCustomHook()", () => {
it("Should return correctly mapped props", () => {
const { result } = renderHook(() =>
useCustomHook(mockData)
);
const data = result.current[0];
expect(data.field).toBe(mockData.field); // this returns ("some.key.from.json.file") it doesn't use the t function,
// ... //
});
I would to try call a function already mocked. I use vueJS for the frond and Jest as unit test. Below a example of my code. My purpose is to test the call of « anotherFunction". The first test is succeed , not the second.Thanks for help or suggestion
code vueJS:
mounted() {
this.myfunction();
}
methods: {
myfunction() {
this.anotherFunction();
}
}
Jest code:
describe('Home.vue', () => {
let wrapper = null;
const options = {
mocks: {
$t: () => 'some specific text',
},
methods: {
myFunction: jest.fn(),
},
};
it('Should renders Home Component', () => {
// Given
wrapper = shallowMount(Home, options);
// Then
expect(wrapper).toBeTruthy();
});
it('Should call anotherFunction', async (done) => {
// Given
wrapper.vm.anotherFunction = jest.fn().mockResolvedValue([]);
// When
await wrapper.vm.myFunction();
// THIS THE PROBLEM, myFunction is mocked and I can't call the function 'anotherFunction' inside...
// Then
// expect(wrapper.vm.anotherFunction).toHaveBeenCalled();
});
});
I was finding a good way to help you if this test case. So, I thought in something like the chuck code below:
import { mount } from '#vue/test-utils';
describe('Home', () => {
it('method calls test case', () => {
const anotherMethodMock = jest.fn();
wrapper = mount(Home, {
methods: {
anotherMethod: anotherMethodMock
}
});
expect(anotherMethodMock).toHaveBeenCalled();
});
});
But, the Jest threw the following exception:
[vue-test-utils]: overwriting methods via the methods property is deprecated and will be removed in the next major version. There is no clear migration path for themethods property - Vue does not support arbitrarily replacement of methods, nor should VTU. To stub a complex m ethod extract it from the component and test it in isolation. Otherwise, the suggestion is to rethink those tests.
I had the following insight, maybe, in this case, should be better to test the side effect of this anotherMethod calling. What does it change? Is something being shown to the user?
I believe that here we have started from the wrong concept.
I hope that this tip could be useful :)
As suggested by #Vinícius Alonso, We should avoid using methods and setMethods in our test cases because of it's deprecation. But you can still test the mounted lifecycle by mocking the functions that are being called during mount. So you can do something similar to below snippet.
describe('Mounted Lifecycle', () => {
const mockMethodOne = jest.spyOn(MyComponent.methods, 'methodOne');
const mockMethodTwo = jest.spyOn(MyComponent.methods, 'methodTwo');
it('Validate data and function call during mount', () => {
const wrapper = shallowMount(MyComponent);
expect(mockMethodOne).toHaveBeenCalled();
expect(mockMethodTwo).toHaveBeenCalled();
})
})
Do mount/shallowMount inside it only rather putting it outside of it as it was not working in my case. You can checkout more details on it if you want.
Can somebody please explain to me why a mocked function passed in a methods object to shallowMount can not be accessed in the test through the wrapper object and instead must be accessed by first creating a variable as a reference to the mocked function?
I have tried mount and shallowMount, created/mounted hooks and also by calling the function directly as opposed to inside the created/mounted hook.
// TestComponent.spec.js
import TestComponent from '#/components/TestComponent'
import { shallowMount, createLocalVue } from '#vue/test-utils'
const localVue = createLocalVue()
const setLoadingMock = jest.fn() // mock function that is accessible in the test
function createWrapper () {
const defaultMountingOptions = {
localVue,
methods: {
setLoading: setLoadingMock
}
}
return shallowMount(TestComponent, defaultMountingOptions)
}
describe('TestComponent.vue', () => {
let wrapper
beforeEach(() => {
wrapper = createWrapper()
});
it('will call setLoading', () => {
expect(wrapper.vm.setLoading).toHaveBeenCalled()
// FAILS. Console message:
// Matcher error: received value must be a mock or spy function
// Received has type: function
// Received has value: [Function bound mockConstructor]
})
it('will call setLoading', () => {
expect(setLoadingMock).toHaveBeenCalled() // PASSES
})
})
TestComponent.vue
export default {
name: 'TestComponent',
mounted () {
this.setLoading()
},
methods: {
setLoading () {
console.log('Original method'); // Never logs
}
}
}
mount or shallowMount are not important in this case. mount means test will mount component and its child components, while shallowMount will mount only component and stub its child components.
You are mocking the setLoading method, which means that you are replacing the original method with a mock. Meaning, when setLoading method is called, it won't run the code from your component, but code from the test mock - in this case jest.fn().
Purpose of mocking is to check if the mocked method was called correctly.
Also, wrapper.vm.setLoading calls the setLoading method.
Instead of referencing the wrapper instance, you should spy the method, e.g.:
const setLoading = jest.spyOn(wrapper.vm, 'setLoading');
expect(setLoading).toHaveBeenCalled() ;
EDIT
Current example,
it('CALLED THE canOpenURL FUNCTION', () => {
const wrapper = mount(<ResourceCardComponent {...mockProps} />);
const canOpenURLSpy = jest.spyOn(Linking, 'canOpenURL');
wrapper.find('TouchableOpacity').simulate('click');
expect(canOpenURLSpy).toHaveBeenCalled();
canOpenURLSpy.mockReset();
canOpenURLSpy.mockRestore();
});
Error
expect(jest.fn()).toHaveBeenCalled() Expected mock function to have
been called.
Problem
I am using Jest & Enzyme to test a class made with React Native. This class has a function inside of it that when fired off uses the Linking library to call canOpenUrl and openUrl. I can simulate the click event on the mounted component but I am having trouble knowing how much of this I can actually test.
My goal is to check if Linking.canOpenUrl ever fires off.
Exmaple
The function inside the component looks like this,
onPressLink() {
console.log('HEY THIS FUNCTION FIRED WOOT WOOT');
Linking.canOpenURL(this.props.url).then((supported) => {
if (supported) {
Linking.openURL(this.props.url);
}
});
}
I can simulate this firing off like this,
describe('onPressLink has been called!', () => {
it('It clicks the mock function onPressLink!', (done) => {
const wrapper = mount(<MyComponent {...mockProps} />);
const onPressLink = jest.fn();
const a = new onPressLink();
wrapper.find('TouchableOpacity').first().simulate('click');
expect(onPressLink).toHaveBeenCalled();
done();
});
});
Now that does work, but my goal is to use something like this,
expect(Linking.canOpenUrl).toHaveBeenCalled();
But I keep getting this error,
TypeError: Cannot read property '_isMockFunction' of undefined
Current code that is trying to check if this function is ever fired off. Which is inside the parent function that is clicked with the simulate method,
it('calls canOpenURL', () => {
const wrapper = mount(<MyComponent {...mockProps} />);
const canOpenURL = jest.spyOn(wrapper.instance, 'onPressLink');
wrapper.find('TouchableOpacity').simulate('click');
expect('Linking.canOpenUrl').toHaveBeenCalled();
});
Question
What is the proper way to check to see if Linking.canOpenURL is fired when its parent function is executed?
(Since Jest 19.0.0+)
You can spy on the Linking module methods using jest.spyOn().
(1) Tell jest to spy on the module method:
const spy = jest.spyOn(Linking, 'canOpenURL');
(2) After doing everything you need to test it, check the spy:
expect(spy).toHaveBeenCalled();
(3) Clean up and stop spying on the module method
spy.mockReset();
spy.mockRestore();
If you don't want the tests to use the actual implementation of the methods, you can fake them like this:
jest.spyOn(Linking, 'canOpenURL').mockImplementation(() => Promise.resolve());
Where the function passed to mockImplementation will be whatever you want the method to do when called.
Ref https://facebook.github.io/jest/docs/en/jest-object.html#jestspyonobject-methodname
When using the actual implementation of your module method, which is asynchronous, the promise might not have been resolved by the time you tested it. You need to make sure any promise is resolved in your method implementation before making any assertions on it.
One way to deal with this is using async/await, like so:
it('...', async () => {
// Wait for promise to resolve before moving on
await wrapper.instance().onPressLink();
// make your assertions
expect(...);
});
Another option is using expect().resolves, available since Jest 20.0.0, where you wait for some promise in the argument to expect() to resolve with a value before making an assertion on that value.
expect(somePromiseThatEventuallyResolvesWithValue).resolves.toBe(Value);
I've done in simplest way:
Steps to spy:
Make spy object for original function using jest
Call original function with / without argument(s)
Assert the function which should be called with valid argument(s)
Reset mock
Restore mock
Here is the sample example
DefaultBrowser.ts which is actual class.
import { Linking } from 'react-native';
export const openDefaultBrowser = async url => {
if (await Linking.canOpenURL(url)) {
Linking.openURL(url);
}
};
DefaultBrowser.test.ts which is test case class.
import { openDefaultBrowser } from '../DefaultBrowser';
import { Linking } from 'react-native';
describe('openDefaultBrowser with validate and open url', () => {
it('validate url', async () => {
const spy = jest.spyOn(Linking, 'canOpenURL');
openDefaultBrowser('https://www.google.com');
expect(spy).toBeCalledWith('https://www.google.com');
spy.mockReset();
spy.mockRestore();
});
it('open url', async () => {
const spy = jest.spyOn(Linking, 'openURL');
openDefaultBrowser('https://www.google.com');
expect(spy).toBeCalledWith('https://www.google.com');
spy.mockReset();
spy.mockRestore();
});
});
Hope this helps you.
it('open url', async () => {
jest.spyOn(Linking, 'canOpenURL')
const spy = jest.spyOn(Linking, 'openURL')
openURL(sitePath)
await waitFor(() => {
expect(spy).toHaveBeenCalledWith(sitePath)
})
spy.mockReset()
spy.mockRestore()
})