CODEWITHSUNDEEP
reactjsunit-testingjestjsenzyme
Harrish Kumar
Harrish Kumar

Reputation: 126

How to mock variable in Jest?

Foo.jsx

import React from 'react';

export default (props) => {
  let {val} = props;

  if (val) {
    return 'ReactComponentFail';
  } else {
    return 'ReactComponent';
  }
};

Foo.test.js

import React from 'react';
import Enzyme, { shallow } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
import Foo from './Foo';

Enzyme.configure({ adapter: new Adapter() });

let wrapper;

describe('foo test', () => {
  let props = { val: 0 }
  wrapper = shallow(<Foo {...props} />);

  test('component test', () => {
    expect(wrapper.text()).toEqual('ReactComponent');
  });
});

How can i mock props? so, that i can get 100% code coverage any help would be highly appreciated. I can't find anything on google regarding how to mock props.

Upvotes: 1

Views: 9668

Answers (1)

Lin Du
Lin Du

Reputation: 102237

Create mocked props and pass it to your SFC.

E.g.

foo.jsx:

import React from 'react';

export default (props) => {
  let { val } = props;

  if (val) {
    return 'ReactComponentFail';
  } else {
    return 'ReactComponent';
  }
};

foo.test.jsx:

import React from 'react';
import { shallow } from 'enzyme';
import Foo from './foo';

describe('foo test', () => {
  test('should return ReactComponent', () => {
    let props = { val: 0 };
    let wrapper = shallow(<Foo {...props} />);
    expect(wrapper.text()).toEqual('ReactComponent');
  });
  test('should return ReactComponentFail', () => {
    let props = { val: 1 };
    let wrapper = shallow(<Foo {...props} />);
    expect(wrapper.text()).toEqual('ReactComponentFail');
  });
});

unit test result with 100% coverage:

 PASS  stackoverflow/62694921/foo.test.jsx (10.41s)
  foo test
    ✓ should return ReactComponent (6ms)
    ✓ should return ReactComponentFail

----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |     100 |      100 |     100 |     100 |                   
 foo.jsx  |     100 |      100 |     100 |     100 |                   
----------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        11.845s, estimated 12s

Upvotes: 3

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