feat(angular): integrate back-button with ng router

angular/src/providers/nav-controller.ts

@@ -1,6 +1,7 @@
 import { Injectable, Optional } from '@angular/core';
 import { Location } from '@angular/common';
 import { NavigationExtras, Router, UrlTree } from '@angular/router';
+import { BackButtonEvent } from '@ionic/core';
 
 export const enum NavIntent {
   Auto,
@@ -19,7 +20,11 @@ export class NavController {
   constructor(
     private location: Location,
     @Optional() private router?: Router
-  ) {}
+  ) {
+    window && window.addEventListener('ionBackButton', (ev) => {
+      (ev as BackButtonEvent).detail.register(0, () => this.goBack());
+    });
+  }
 
   navigateForward(url: string | UrlTree | any[], animated?: boolean, extras?: NavigationExtras) {
     this.setIntent(NavIntent.Forward, animated);

core/package.json

@@ -32,6 +32,7 @@
     "@stencil/sass": "0.1.0",
     "@stencil/utils": "latest",
     "@types/jest": "^23.3.1",
+    "agadoo": "^1.0.0",
     "autoprefixer": "^9.0.2",
     "chromedriver": "^2.38.3",
     "clean-css-cli": "^4.1.11",
@@ -77,8 +78,9 @@
     "theme-builder:dev": "sd concurrent \"npm run theme-app-build -- --watch\" \"stencil build --dev --watch\" \"stencil-dev-server\" \"npm run theme-server\" ",
     "theme-server": "node scripts/theme-builder/server.js",
     "tsc": "./node_modules/.bin/tsc -p .",
-    "validate": "npm run lint && npm run test && npm run build",
-    "validate.ci": "npm run lint && npm run test && npm run build --max-workers 1 --debug"
+    "test.treeshake": "agadoo dist/collection/index.js",
+    "validate": "npm run test.treeshake && npm run lint && npm run test && npm run build",
+    "validate.ci": "npm run test.treeshake && npm run lint && npm run test && npm run build --max-workers 1 --debug"
   },
   "author": "Ionic Team",
   "license": "MIT",