epicLoadingExample.js

import { from, of, concat } from 'rxjs';
import { catchError, mergeMap, switchMap } from 'rxjs/operators';

const exampleEpic = action$ =>
    action$.pipe(
      ofType(types.ACTION_REQUEST),
      switchMap(({ payload }) =>
        concat(
          of(loadingList()), // Here we define the loading action for our list
          from(api.get(payload.data)).pipe(
            mergeMap(response =>
              of(
                addDataAction(response), // action 1
                pushInfoSnackbar('created successfully') // action 2
              )
            ),
            catchError(() =>
              of(pushWarningSnackbar('Failed to create shareable folder')); // failed action
            )
          )
        )
      )
    );