- first code with simple leaflet map

src/app/app.module.ts

@@ -0,0 +1,21 @@
+import { NgModule } from "@angular/core";
+import { BrowserModule } from "@angular/platform-browser";
+
+import { AppComponent } from './app.component';
+import { MapComponent } from './map/map.component';
+
+@NgModule({
+    // declarations: The components, directives, and pipes that belong to this NgModule.
+    declarations: [AppComponent, MapComponent],
+    // imports: Other modules whose exported classes are needed by component templates declared in this NgModule.
+    imports: [BrowserModule],
+    providers: [],
+    // bootstrap: The main application view, called the root component, which hosts all other application views. 
+    // Only the root NgModule should set the bootstrap property.
+    bootstrap: [AppComponent],
+  })
+  export class AppModule {
+    constructor() {}
+  }
+  
+  // https://medium.com/@hubert.zub/using-babel-7-and-preset-typescript-to-compile-angular-6-app-448eb1880f2c