Jest Asynchronous API Mocking

Question

I have searched this issue on stack-overflow, but couldn't find anything similar to me use case.

I have container component like this.

import React, { Component } from 'react';
import PropTypes from 'prop-types';

// API
import BookingAPI from '../../../../api/BookingAPI';

class CustomerProfilePage extends Component {
  state = {
    list: [],
    totalRecords: 0,
    pageNo: 1,
  };

  componentDidMount() {
    const { pageNo } = this.state;
    this.onGetBookingList({ pageNo });
  }

  onGetBookingList = async ({ pageNo = 0 }) => {
    const { match } = this.props;
    try {
      const result = await BookingAPI.onGetBookingList({
        passengerId: match.params.customerId,
        sortProperties: ['id'],
        limitCount: 10,
        pageNo,
      });
      this.setState({
        list: result.items,
        totalRecords: result.totalRecords,
     });
    } catch (error) {
      // console.log('error is', error);
    }
  };

  render() {
    return <div></div>;
  }
}

export default CustomerProfilePage;

I want to test BookingAPI.onGetBookingList in my this.onGetBookingList method.

So far this is what I have tried, am I missing something here..

This is my CustomerProfilePage.test.js file below

import React from 'react';
import { shallow } from 'enzyme';

// Components
import CustomerProfilePage from './CustomerProfilePage';

function setup() {
  const props = {
     match: {
       params: {
         customerId: 1,
       },
     },
  };
  return shallow(<CustomerProfilePage {...props} />);
}

describe('CustomerProfilePage', () => {
  it('Should update state on onGetBookingList call', async () => {
    jest.mock('../../../../api/BookingAPI', () => ({
      onGetBookingList: () => {
        const data = { items: [{ value: 1 }, { value: 2 }], totalRecords: 1 };
        return jest.fn().mockReturnValue(data);
      },
    }));
    const wrapper = setup();
    await wrapper.instance().onGetBookingList({ pageNo: 1 });
    wrapper.update();
    expect(wrapper.state().totalRecords).toBe(1); // should be 1, but is 0
 });
});

For the purpose of simplicity I have not written the code in my render because I wanted to focus on the code part where I am mocking an API call.

Answer 1

Since onGetBookingList has to be an async function

you can define async method like this:

jest.mock('../../../../api/BookingAPI', () => ({
    async onGetBookingList() {
        return data;
    }
}));

or you can use jest.fn() which retuns a Promise

jest.mock('../../../../api/BookingAPI', () => ({
    onGetBookingList: jest.fn(() => Promise.resolve(data))
}));

or use jest.fn().mockResolvedValue()

jest.mock('../../../../api/BookingAPI', () => ({
    onGetBookingList: jest.fn().mockResolvedValue(data)
}));

and then

import { onGetBookingList } from '../../../../api/BookingAPI';

it('should be working with all of the above mocks', async () => {
    const { totalRecords } = await onGetBookingList();
    expect(totalRecords).toBe(1);
}

working exmaple