React Jest Test coverage showing untested line (default props) - reactjs

Question

I am running a test on the simple button component. All works fine, however, in the test coverage I am getting an untested line (21: onClick: () => { return true }). This line points to the default props function. How can I make sure that I have covered the unit test for this line?
My component:
import React from 'react';
import { Link } from 'react-router-dom';
import PropTypes from 'prop-types';
export const Button = (props) => {
return (
<Link
to={props.link}
className={props.classes}
onClick={props.onClick}
>
{props.title}
</Link>
);
};
Button.defaultProps = {
link: '/',
title: 'Home',
classes: 'btn btn--primary',
onClick: () => { return true }
}
Button.propTypes = {
link: PropTypes.string,
title: PropTypes.string,
classes: PropTypes.string,
onClick: PropTypes.func
};
export default Button;
My test:
import React from 'react';
import { shallow } from 'enzyme';
import { Button } from '../../../components/partials/Button';
test('should render button', () => {
const wrapper = shallow(<Button link='/test' title='Home' classes='btn btn--primary' onClick={ () => { return true }} />);
expect(wrapper).toMatchSnapshot();
const props = wrapper.props();
expect(props.to).toBe('/test');
expect(props.className).toBe('btn btn--primary');
expect(props.onClick).toBe(props.onClick);
expect(props.children).toBe('Home');
});
test('should have default onClick', () => {
expect(Button.defaultProps.onClick).toBeDefined();
});

Answer 1

You need to run the onClick function in order for it to count for coverage. So, make a test that simulates a click event on the button, which will trigger its onClick function:
it('does something when clicked', () => {
const wrapper = shallow(<Button link='/test' title='Home' classes='btn btn--primary' onClick={ () => { return true }} />);
wrapper.simulate('click');
expect(...);
});