i need to cover my code with some unit tests and in one of then i have the following situation.
app.tsx
async someMethod(
.
.
.
window.location.replace(sessionStorage.getItem(REDIRECT_VALUE));
.
.
.
)
and in my test file
window.location.replace = jest.fn();
.
.
somevariable.SomeMethod = jest.fn();
expect(window.location.replace).toHaveBeenCalledWith("some url to redirect on");
i'm getting the followein error : Cannot assign to read only property 'replace' of object '[object Location]'
i've tried other aproachs like
backupState = window.location
delete window.location;
window.location = Object.assign(new URL("https://example.org"), {
ancestorOrigins: "",
replace: jest.fn()
});
});
but i get different erros for each one of them, is there another way of doing it?
Previously i was using :
history.location.push(sessionStorage.getItem(REDIRECT_VALUE));
and
expect(auth.history.push).toHaveBeenCalled();
and in that case the test went OK.
One way to test it is:
Create a mock function to location.replace:
const replaceMock = jest.fn();
And spyOn window, replacing location object and setting the replaceMock to replace.
Complete test example:
const replaceMock = jest.fn();
describe('replace Location test ', () => {
it('should call location with specific arg', () => {
jest.spyOn(global as any, 'window', 'get').mockImplementationOnce(() => ({
location: {
replace: replaceMock,
},
}));
someMethod();
expect(replaceMock).toBeCalledWith('XX Value you want to test XX');
});
});