If the component had unmounted by the time the request completed, the 'infamous' "Can't perform a React state update on an unmounted component" warning would have been printed to console. However, when I try to write a failing test for this case, enzyme doesn't issue a warning and considers the test to have passed.
This is my test's code:
import React from 'react';
import { mount } from 'enzyme';
import { act } from 'react-dom/test-utils';
// auxiliary class
class MockPromise {
const thenCallbacks = [];
then(callback) {
this.thenCallbacks.push(callback);
return this;
}
resolve(val) {
this.thenCallbacks.forEach((callback) => callback(val));
}
}
describe('TestComponent', () => {
test('should not set state on unmounted component', () => {
const promise = new MockPromise();
const fetchSomethingFromAPI = () => promise;
const wrapper = mount(<TestComponent fetchSomethingFromAPI={fetchSomethingFromAPI} />);
wrapper.unmount();
act(() => {
promise.resolve(null);
});
wrapper.update();
});
});
This problem seems to only be affecting functional components, for class components the test would fail with the "setState() can only be called on class components" error message; while the message is not the same as it would be in dev environment, at least it allows me to test my class components for this particular case.
Current behavior
Setting state on an unmounted functional component doesn't issue a warning and allows the test to pass
Expected behavior
Setting state on an unmounted functional component should issue a warning and fail the test
Consider this simple component, which sends an API request on mount and sets component's state to the response:
If the component had unmounted by the time the request completed, the 'infamous' "Can't perform a React state update on an unmounted component" warning would have been printed to console. However, when I try to write a failing test for this case, enzyme doesn't issue a warning and considers the test to have passed. This is my test's code:
This problem seems to only be affecting functional components, for class components the test would fail with the "setState() can only be called on class components" error message; while the message is not the same as it would be in dev environment, at least it allows me to test my class components for this particular case.
Current behavior
Setting state on an unmounted functional component doesn't issue a warning and allows the test to pass
Expected behavior
Setting state on an unmounted functional component should issue a warning and fail the test
Your environment
API
Version
Adapter