Test Action of Redux-thunk use JEST - unit-testing

Question

I want to write a test for Axios use Jest Framework. I'm using Redux.
Here is my function get-request of Axios
export const getRequest = a => dispatch => {
return axios
.get(a)
.then(function(response) {
dispatch({
type: FETCH_DATA,
payload: response.data
});
})
.catch(function(error) {
dispatch({ type: ERROR_DATA, payload: { status: error.response.status, statusText: error.response.statusText } });
});
};
thanks in advance :)

Answer 1

Here is the solution:
index.ts:
import axios from 'axios';
export const FETCH_DATA = 'FETCH_DATA';
export const ERROR_DATA = 'ERROR_DATA';
export const getRequest = a => dispatch => {
return axios
.get(a)
.then(response => {
dispatch({
type: FETCH_DATA,
payload: response.data
});
})
.catch(error => {
dispatch({ type: ERROR_DATA, payload: { status: error.response.status, statusText: error.response.statusText } });
});
};
index.spec.ts:
import axios from 'axios';
import { getRequest, FETCH_DATA, ERROR_DATA } from './';
describe('getRequest', () => {
const dispatch = jest.fn();
it('should get data and dispatch action correctly', async () => {
const axiosGetSpyOn = jest.spyOn(axios, 'get').mockResolvedValueOnce({ data: 'mocked data' });
await getRequest('jest')(dispatch);
expect(axiosGetSpyOn).toBeCalledWith('jest');
expect(dispatch).toBeCalledWith({ type: FETCH_DATA, payload: 'mocked data' });
axiosGetSpyOn.mockRestore();
});
it('should dispatch error', async () => {
const error = {
response: {
status: 400,
statusText: 'client error'
}
};
const axiosGetSpyOn = jest.spyOn(axios, 'get').mockRejectedValueOnce(error);
await getRequest('ts')(dispatch);
expect(axiosGetSpyOn).toBeCalledWith('ts');
expect(dispatch).toBeCalledWith({ type: ERROR_DATA, payload: error.response });
axiosGetSpyOn.mockRestore();
});
});
Unit test result and coverage:
PASS 45062447/index.spec.ts
getRequest
✓ should get data and dispatch action correctly (9ms)
✓ should dispatch error (2ms)
----------|----------|----------|----------|----------|-------------------|
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files | 100 | 100 | 100 | 100 | |
index.ts | 100 | 100 | 100 | 100 | |
----------|----------|----------|----------|----------|-------------------|
Test Suites: 1 passed, 1 total
Tests: 2 passed, 2 total
Snapshots: 0 total
Time: 1.551s, estimated 3s
Here is the code: https://github.com/mrdulin/jest-codelab/tree/master/src/stackoverflow/45062447