Assert onBlur() funciton in functional component jest - reactjs

Question

I wrote a test case to call onBlur method, but I'm getting an error when I try to assert it. Here is the above test case.
it("call the handlingBlurEmail method", () => {
const wrapper = mount(
<App childRef={() => {}} />
);
const comp = wrapper.find({ id: "email" }).first();
comp.prop("onBlur")({
target: { id: "email", value: "test#gmail.com" }
});
expect(
wrapper
.find("AccountForm")
.state()
.onBlur()
).toHaveBeenCalled();
});
and the function for which I'm writing test case is
mailReference = React.createRef();
handlingEmailBlur = events => {
this.mailReference.current.validate(events.target.value);
};
render = () {
......
return (
<div className="Form1">
onBlur={this.handlingEmailBlur}
</div>
)
.....
}
Please let me know how to add assert statement in order to call the onBlur() method in the above test case

Answer 1

Here is the unit testing solution:
index.tsx:
import React, { Component } from 'react';
class App extends Component {
mailReference = React.createRef();
handlingEmailBlur = (events) => {
this.mailReference.current.validate(events.target.value);
};
render() {
return (
<div className="Form1" onBlur={this.handlingEmailBlur}>
some component
</div>
);
}
}
export default App;
index.spec.tsx:
import App from './index';
import { mount } from 'enzyme';
import React from 'react';
describe('59455504', () => {
afterEach(() => {
jest.restoreAllMocks();
});
it('call the handlingBlurEmail method', () => {
const mailReference = { current: { validate: jest.fn() } };
jest.spyOn(React, 'createRef').mockReturnValue(mailReference);
const wrapper = mount(<App childRef={() => {}} />);
const mEvent = {
target: { id: 'email', value: 'test#gmail.com' },
};
wrapper.find('.Form1').prop('onBlur')(mEvent);
expect(mailReference.current.validate).toBeCalledWith(mEvent.target.value);
});
});
Unit test result with 100% coverage:
PASS src/stackoverflow/59455504/index.spec.jsx (8.328s)
59455504
✓ call the handlingBlurEmail method (40ms)
-----------|----------|----------|----------|----------|-------------------|
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s |
-----------|----------|----------|----------|----------|-------------------|
All files | 100 | 100 | 100 | 100 | |
index.jsx | 100 | 100 | 100 | 100 | |
-----------|----------|----------|----------|----------|-------------------|
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 9.769s
Source code: https://github.com/mrdulin/jest-codelab/tree/master/src/stackoverflow/59455504