fetchMock function makes actual API calls instead of mocking the requests - reactjs

Question

I am trying to test my signupAction shown below.
import axios from 'axios';
import actionTypes from '../action_types';
import { apiRequest } from '../common_dispatch';
export const signupAction = (user) => async (dispatch) => {
dispatch(apiRequest(true));
await axios
.post(`${process.env.REACT_APP_API_URL}/users`, { ...user }, {
headers: { 'Content-Type': 'application/json' },
})
.then((response) => {
dispatch(
{
type: actionTypes.REGISTER_SUCCESS,
payload: response.data.user,
},
);
dispatch(apiRequest(false));
})
.catch((error) => {
let errors = 'ERROR';
if (error.message === 'Network Error') {
errors = error.message;
} else {
errors = error.response.data.errors;
console.log(error);
}
dispatch(
{
type: actionTypes.REGISTER_FAIL,
payload: errors,
},
);
dispatch(apiRequest(false));
});
};
I figured I could mock the API call above using the fetchMock library. The problem is fetchMock makes actual calls hence the test passes in the first intance but fails when I run it the second time because the user I am trying to sign up already exists. my test is as shown below.
mport configureMockStore from 'redux-mock-store';
import * as actions from './signup.action';
import mocks from './mocks';
import thunk from 'redux-thunk';
import fetchMock from 'fetch-mock';
const middlewares = [thunk]
const mockStore = configureMockStore(middlewares)
describe('signUp actions', () => {
afterEach(() => {
fetchMock.resetMocks();
console.log('yess bro am called')
})
it('dispatches create REGISTER_FAIL when signup has been done', async () => {
fetchMock.postOnce('/users', { ...mocks.user }, {
headers: { 'Content-Type': 'application/json' },
});
const expectedActions = [
{ type: 'API_REQUEST', payload: true },
{ type: 'REGISTER_FAIL', payload: { email: "Email karanilarrygmail.com is not a valid email" } },
{ type: 'API_REQUEST', payload: false },
]
const store = mockStore(mocks.user);
return store.dispatch(actions.signupAction(mocks.user)).then(() => {
expect(store.getActions()).toEqual(expectedActions)
})
});
mocks.user is an object containing the user signup data.
What am I doing wrong