wraps axios request in cancellable observable

observable-from-axios.js

import { Observable, from } from 'rxjs';
import { CancelToken, AxiosResponse } from "axios";

/**
 * @callback AxiosFn
 * @param {CancelToken} cancelToken
 * @returns {Promise<AxiosResponse>}
 */

/**
 * wraps axios request in cancellable observable
 * @param {AxiosFn} axiosFn
 * @returns {Observable<AxiosResponse>}
 */
export function observableFromAxios(axiosFn) {
    return new Observable(subscriber => {
        const cancelToken = CancelToken.source();
        const promise = axiosFn(cancelToken);
        from(promise).subscribe(subscriber);
        return () => {
            cancelToken.cancel("canceled by observable stream");
        };
    });
}