NativeScript-Angular HMR

livesync-navigation.ts

import { NgZone } from "@angular/core";
import { Router } from "@angular/router";
import { onBeforeLivesync, onAfterLivesync } from "nativescript-angular/platform-common";
import { RouterExtensions } from "nativescript-angular/router";

let cachedUrl: string;
onBeforeLivesync.subscribe(moduleRef => {
    console.log("#### onBeforeLivesync");
    if (moduleRef) {
        const router = <Router>moduleRef.injector.get(Router);
        cachedUrl = router.url;
        console.log("-------> Caching URL: " + cachedUrl);
    }
});

onAfterLivesync.subscribe(({ moduleRef, error }) => {
    console.log(`#### onAfterLivesync moduleRef: ${moduleRef} error: ${error}`);
    if (moduleRef) {
        const router = <RouterExtensions>moduleRef.injector.get(RouterExtensions);
        const ngZone = <NgZone>moduleRef.injector.get(NgZone);
        if (router && cachedUrl) {
          ngZone.run(() => { // <--  should be wrapped in ngZone
            router.navigateByUrl(cachedUrl, { animated: false });
          });
        }
    }
});

main.ts

import { platformNativeScriptDynamic } from "nativescript-angular/platform";
import { AppOptions } from "nativescript-angular/platform-common";

import { AppModule } from "./app/app.module";

// Optional - attach to livesync hooks and perfrom navigation
import "./livesync-navigation";

let options: AppOptions = {};

if (module["hot"]) {
    options.hmrOptions = {
        moduleTypeFactory: () => AppModule,
        livesyncCallback: (platformReboot) => {
            setTimeout(platformReboot, 0);
        },
    };

    // Path to your app module.
    // You might have to change it if your module is in a different place.
    module["hot"].accept(["./app/app.module"], () => {
        global["hmrRefresh"]();
    });
}

// Don't forget to pass the options when creating the platform
platformNativeScriptDynamic(options).bootstrapModule(AppModule);

Import on line 4 should be import { AppModule } from "./app/app.module";

Thank you, @edwinquaihoi! I updated the import. :)