fix(compiler-cli): add support for more than 2 levels of nested lazy routes

This change adds Compiler CLI support for any level of nesting for lazy routes.

For example `{app-root}/lazy-loaded-module-1/lazy-loaded-module-2/lazy-loaded-module-3`

Where `lazy-loaded-module-3` is lazy loaded from `lazy-loaded-module-2`,
and `lazy-loaded-module-2` is lazy loaded from module `lazy-loaded-module-1`,
and `lazy-loaded-module-1` is lazy loaded from `AppModule`

Fixes angular/angular-cli#3663

modules/@angular/compiler-cli/integrationtest/ngtools_src/feature/lazy-feature-nested.module.ts

@@ -0,0 +1,23 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Component, NgModule} from '@angular/core';
+import {RouterModule} from '@angular/router';
+
+@Component({selector: 'lazy-feature-comp', template: 'lazy feature, nested!'})
+export class LazyFeatureNestedComponent {
+}
+
+@NgModule({
+  imports: [RouterModule.forChild([
+    {path: '', component: LazyFeatureNestedComponent, pathMatch: 'full'},
+  ])],
+  declarations: [LazyFeatureNestedComponent]
+})
+export class LazyFeatureNestedModule {
+}

modules/@angular/compiler-cli/integrationtest/ngtools_src/feature/lazy-feature.module.ts

@@ -16,7 +16,10 @@ export class LazyFeatureComponent {
 @NgModule({
   imports: [RouterModule.forChild([
     {path: '', component: LazyFeatureComponent, pathMatch: 'full'},
-    {path: 'feature', loadChildren: './feature.module#FeatureModule'}
+    {path: 'feature', loadChildren: './feature.module#FeatureModule'}, {
+      path: 'nested-feature',
+      loadChildren: './lazy-feature-nested.module#LazyFeatureNestedModule'
+    }
   ])],
   declarations: [LazyFeatureComponent]
 })

modules/@angular/compiler-cli/integrationtest/test/test_ngtools_api.ts

@@ -191,6 +191,8 @@ function lazyRoutesTest() {
     './lazy.module#LazyModule': 'lazy.module.ts',
     './feature/feature.module#FeatureModule': 'feature/feature.module.ts',
     './feature/lazy-feature.module#LazyFeatureModule': 'feature/lazy-feature.module.ts',
+    './feature.module#FeatureModule': 'feature/feature.module.ts',
+    './lazy-feature-nested.module#LazyFeatureNestedModule': 'feature/lazy-feature-nested.module.ts',
     'feature2/feature2.module#Feature2Module': 'feature2/feature2.module.ts',
     './default.module': 'feature2/default.module.ts',
     'feature/feature.module#FeatureModule': 'feature/feature.module.ts'

modules/@angular/compiler-cli/src/ngtools_impl.ts

@@ -15,8 +15,6 @@
 import {AotCompilerHost, StaticReflector, StaticSymbol} from '@angular/compiler';
 import {NgModule} from '@angular/core';
 
-
-
 // We cannot depend directly to @angular/router.
 type Route = any;
 const ROUTER_MODULE_PATH = '@angular/router/src/router_config_loader';
@@ -63,29 +61,37 @@ export function listLazyRoutesOfModule(
   const className = entryRouteDef.className;
 
   // List loadChildren of this single module.
-  const staticSymbol = reflector.findDeclaration(modulePath, className, containingFile);
+  const appStaticSymbol = reflector.findDeclaration(modulePath, className, containingFile);
   const ROUTES = reflector.findDeclaration(ROUTER_MODULE_PATH, ROUTER_ROUTES_SYMBOL_NAME);
   const lazyRoutes: LazyRoute[] =
-      _extractLazyRoutesFromStaticModule(staticSymbol, reflector, host, ROUTES);
-  const routes: LazyRouteMap = {};
+      _extractLazyRoutesFromStaticModule(appStaticSymbol, reflector, host, ROUTES);
 
-  lazyRoutes.forEach((lazyRoute: LazyRoute) => {
+  const allLazyRoutes = lazyRoutes.reduce(
+      function includeLazyRouteAndSubRoutes(allRoutes: LazyRouteMap, lazyRoute: LazyRoute):
+          LazyRouteMap {
             const route: string = lazyRoute.routeDef.toString();
-    _assertRoute(routes, lazyRoute);
-    routes[route] = lazyRoute;
+            _assertRoute(allRoutes, lazyRoute);
+            allRoutes[route] = lazyRoute;
+
+            // StaticReflector does not support discovering annotations like `NgModule` on default
+            // exports
+            // Which means: if a default export NgModule was lazy-loaded, we can discover it, but,
+            //  we cannot parse its routes to see if they have loadChildren or not.
+            if (!lazyRoute.routeDef.className) {
+              return allRoutes;
+            }
 
             const lazyModuleSymbol = reflector.findDeclaration(
                 lazyRoute.absoluteFilePath, lazyRoute.routeDef.className || 'default');
-    const subRoutes = _extractLazyRoutesFromStaticModule(lazyModuleSymbol, reflector, host, ROUTES);
 
-    // Populate the map using the routes we just found.
-    subRoutes.forEach(subRoute => {
-      _assertRoute(routes, subRoute);
-      routes[subRoute.routeDef.toString()] = subRoute;
-    });
-  });
+            const subRoutes =
+                _extractLazyRoutesFromStaticModule(lazyModuleSymbol, reflector, host, ROUTES);
 
-  return routes;
+            return subRoutes.reduce(includeLazyRouteAndSubRoutes, allRoutes);
+          },
+      {});
+
+  return allLazyRoutes;
 }