Testing onChange function in Jest

Question

I\'m relatively new to Jest and testing in general. I have a component with an input element:

import * as React from \"react\";

export interface inputProps{
            


        

Answer 1

How about this one? I simulate the change event using enzyme and perform a snapshot test. Component

import React, { FunctionComponent, useState } from 'react';

const Index: FunctionComponent = () => {

  const [val, setVal] = useState('');

  const onInputChange = e => {
    e.preventDefault();
    setVal(e.target.value);
  };

  return (
    
  );
};

export default Index;

Unit Test

describe('Index with enzyme', () => {
  it('Should set value to state when input is changed', () => {
    const container = shallow();
    const input = container.find('input');
    input.simulate('change', { preventDefault: jest.fn, target: { value: "foo" } });
    expect(container).toMatchSnapshot();
  });
});

Snapshot

exports[`Index with enzyme Should set value to state when input is changed 1`] = `
  
`;