test-support.js

import thunk from "redux-thunk";
// redux-thunk middleware is what I use in development stage to handle my asynchronous actions.

import configureStore from "redux-mock-store";
// redux-mock-store is a mock(fake copy) store for testing Redux async action creators and middleware. 
//The mock store will create an array of dispatched actions which serve as an action log for tests.

import axios from "axios";
//axios is a promised based module for creating HTTP requests I am using.

import MockAdapter from "axios-mock-adapter";
//axios-mock-adapter is a module for creating a mock HTTP request

const middlewares = [thunk];
//The middlewares variable is an array of all the redux middlewares used in development stage, in my case I am only using thunk thus why it is the only one listed. 

const mockStore = configureStore(middlewares);
//The variable mockStore creates a fake store for testing purposes, basically doing the same thing as  when you call the createStore() method in redux.

const mockAxios = new MockAdapter(axios);
//sets the mock adapter to the axios instance.

export { mockStore, mockAxios };
// I am exporting both variables so I can use it when testing my action creator.