Cookie intercepting for authentication on NativeScript angular

auth-interceptor.service.ts

import { Injectable } from "@angular/core";
import { Observable } from "rxjs";
import { tap } from "rxjs/operators";

import {
    HttpInterceptor,
    HttpHandler,
    HttpRequest,
    HttpEvent
} from "@angular/common/http";


import { StorageService } from "./storage.service";

@Injectable()
export class AuthInterceptorService implements HttpInterceptor {

    constructor(private store: StorageService) {
    }

    intercept(
        req: HttpRequest<any>,
        next: HttpHandler
    ): Observable<HttpEvent<any>> {
        enum Key {
            Login,
            Logout,
            Credentialed,
            Other
        }

        let requestType = Key.Other;

        const loginAPI = "/api/user/login";
        const logoutAPI = "/api/user/logout";

        if (req["url"]) {
            if (req["url"].endsWith(logoutAPI)) {
                requestType = Key.Logout;
            } else if (req["url"].endsWith(loginAPI)) {
                requestType = Key.Login;
            } else if (req["withCredentials"]) {
                requestType = Key.Credentialed;
            }
        }

        if (requestType === Key.Credentialed) {
            const cache = this.store.get(this.constructor.name);
            if (cache) {
                let token: string = "";

                for (const key in cache) {
                    token = `${token}${key}=${cache[key]}; `;
                }

                const newReq = req.clone({
                    headers: req.headers.append("Cookie", token.trim())
                });
                return next.handle(newReq);
            } else {
                requestType = Key.Other;
            }
        }

        if (requestType === Key.Logout) {
            this.store.remove(this.constructor.name);

            return next.handle(req);
        }

        if (requestType === Key.Login) {
            return next.handle(req).pipe(
                tap(
                    response => {
                        if (requestType === Key.Login && response["headers"]) {
                            const cookies = response["headers"].get(
                                "Set-Cookie"
                            );

                            let target = this.store.get(this.constructor.name);
                            if (!target) {
                                target = {};
                            }
                            let idx;

                            let reg = RegExp("(\\S*?)=(\\S*?);", "g");
                            while ((idx = reg.exec(cookies)) !== null) {
                                let key = idx[1];
                                let value = idx[2];
                                if (value === "deleteMe") {
                                    if (key in target) {
                                        delete target[key];
                                        continue;
                                    }
                                } else {
                                    target[key] = value;
                                }
                            }

                            this.store.set(this.constructor.name, target);
                        }
                    },
                    error => {
                        console.log(
                            `Error in Response`
                        );
                    }
                )
            );
        }

        return next.handle(req);
    }
}