diff --git a/packages/core/test/render3/compiler_canonical/back_patch_types_specs.ts b/packages/core/test/render3/compiler_canonical/back_patch_types_specs.ts
new file mode 100644
index 0000000000..7c3e597dfe
--- /dev/null
+++ b/packages/core/test/render3/compiler_canonical/back_patch_types_specs.ts
@@ -0,0 +1,138 @@
+/**
+ * @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, ContentChild, Directive, Injectable, Injector, Input, NgModule, NgModuleFactory, NgModuleRef, OnDestroy, Optional, Pipe, PipeTransform, QueryList, SimpleChanges, TemplateRef, Type, ViewChild, ViewContainerRef} from '../../../src/core';
+import * as r3 from '../../../src/render3/index';
+
+import {pending_pull_22005} from './small_app_spec';
+
+const details_elided = {
+  type: Object,
+} as any;
+export type $ComponentDef$ = any;
+
+///////////
+// Lib A - Compiled pre-Ivy
+//    "enableIvy": false
+//////////
+
+// BEGIN FILE: node_modules/libA/module.ts (Compiled without Ivy)
+@Component({})
+export class LibAComponent {
+}
+
+@NgModule({declarations: [LibAComponent], imports: []})
+export class LibAModule {
+}
+// END FILE: node_modules/libA/module.ts
+// BEGIN FILE: node_modules/libA/module.metadata.json
+// Abridged version of metadata
+const node_modules_libA_module_metadata = {
+  'LibAModule': {
+    refs: ['LibAComponent'],
+    constructorDes: [],
+  },
+  'LibAComponent': {
+    constructorDes: [],
+  }
+};
+// END FILE: node_modules/libA/module.metadata.json
+
+
+///////////
+// Lib B - Compiled with Ivy
+//    "enableIvy": true
+//////////
+
+
+// BEGIN FILE: node_modules/libB/module.ts (Compiled with Ivy)
+@Component({})
+export class LibBComponent {
+  // COMPILER GENERATED
+  static ngComponentDef: $ComponentDef$ = r3.defineComponent(details_elided);
+}
+
+@NgModule({declarations: [LibAComponent], imports: []})
+export class LibBModule {
+  // COMPILER GENERATED
+  static ngInjectorDef = pending_pull_22005.defineInjector(details_elided);
+}
+// END FILE: node_modules/libB/module.ts
+// BEGIN FILE: node_modules/libB/module.metadata.json
+// Abridged version of metadata
+// Must still generate metadata in case it should be consumed with non-ivy application
+// Must mark the metadata with `hasNgDef: true` so that Ivy knows to ignore it.
+const node_modules_libB_module_metadata = {
+  'LibBModule': {refs: ['LibBComponent'], constructorDes: [], hasNgDef: true},
+  'LibBComponent': {constructorDes: [], hasNgDef: true}
+};
+// END FILE: node_modules/libA/module.metadata.json
+
+
+
+///////////
+// Lib B - Compiled with Ivy
+//    "enableIvy": true
+//    "enableIvyBackPatch": true
+//////////
+
+
+// BEGIN FILE: src/app.ts (Compiled with Ivy)
+@Component({})
+export class AppComponent {
+  // COMPILER GENERATED
+  static ngComponentDef: $ComponentDef$ = r3.defineComponent(details_elided);
+}
+
+@NgModule({declarations: [LibAComponent], imports: []})
+export class AppModule {
+  // COMPILER GENERATED
+  static ngInjectorDef = pending_pull_22005.defineInjector(details_elided);
+}
+// END FILE: src/app.ts
+
+// BEGIN FILE: src/main.ts
+// platformBrowserDynamic().bootstrapModule(AppModule);
+// CLI rewrites it later to:
+// platformBrowser().bootstrapModuleFactory(AppModuleFactory);
+// END FILE: src/main.ts
+
+// BEGIN FILE: src/app.ngfactory.ts
+function ngBackPatch_node_modules_libB_module() {
+  ngBackPatch_node_modules_libB_module_LibAComponent();
+  ngBackPatch_node_modules_libB_module_LibAModule();
+}
+
+function ngBackPatch_node_modules_libB_module_LibAComponent() {
+  (LibAComponent as any).ngComponentDef = r3.defineComponent(details_elided);
+}
+
+function ngBackPatch_node_modules_libB_module_LibAModule() {
+  (LibAModule as any).ngInjectorDef = pending_pull_22005.defineInjector(details_elided);
+}
+
+export const AppModuleFactory: NgModuleFactory<AppModule>&{patchedDeps: boolean} = {
+  moduleType: AppModule,
+  patchedDeps: false,
+  create(parentInjector: Injector | null): NgModuleRef<AppModule>{
+      this.patchedDeps && ngBackPatch_node_modules_libB_module() && (this.patchedDeps = true);
+      return details_elided;}
+};
+// BEGIN FILE: src/app.ngfactory.ts
+
+
+// ISSUE: I don't think this works. The issue is that multiple modules get flattened into single
+// module and hence we can't patch transitively.
+// ISSUE: can non-ivy @NgModule import Ivy @NgModule? I assume no, since the flattening of modules
+// happens during compilation.
+
+// BEGIN FILE: src/main.ts
+// platformBrowserDynamic().bootstrapModule(AppModule);
+// CLI rewrites it to:
+// platformBrowser().bootstrapModuleFactory(AppModuleFactory);
+// END FILE: src/main.ts
diff --git a/packages/core/test/render3/compiler_canonical/patch_types_spec.ts b/packages/core/test/render3/compiler_canonical/patch_types_spec.ts
new file mode 100644
index 0000000000..ca4e37374c
--- /dev/null
+++ b/packages/core/test/render3/compiler_canonical/patch_types_spec.ts
@@ -0,0 +1,78 @@
+/**
+ * @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, ContentChild, Directive, Injectable, Input, NgModule, OnDestroy, Optional, Pipe, PipeTransform, QueryList, SimpleChanges, TemplateRef, Type, ViewChild, ViewContainerRef} from '../../../src/core';
+import * as r3 from '../../../src/render3/index';
+import {pending_pull_22005} from './small_app_spec';
+
+/**
+ * GOALS:
+ * - Patch types in tree shakable way
+ * - Generate these types for files which have `metadata.json` (since those are the files which
+ * have not been compiled with Ivy)
+ * - Have build optimizer hoist the patch functions into corresponding types to allow tree-shaking.
+ */
+
+// File: node_modules/some_library/path/public.ts
+// Implies metadata: node_modules/some_library/path/public.metadata.json
+// Assume: node_modules/some_library/index.js re-exports ./path/public.ts#ThirdPartyClass
+@Injectable()
+class ThirdPartyClass {
+}
+
+
+@Injectable()
+class CompiledWithIvy {
+  // NORMATIVE
+  static ngInjectableDef = pending_pull_22005.defineInjectable(
+      {factory: function CompileWithIvy_Factory() { return new CompiledWithIvy(); }});
+  // /NORMATIVE
+}
+
+// import { CompiledWithIvy } from 'some_library';
+@NgModule({providers: [ThirdPartyClass, CompiledWithIvy]})
+class CompiledWithIvyModule {
+  // NORMATIVE
+  static ngInjectorDef = pending_pull_22005.defineInjector({
+    providers: [ThirdPartyClass, CompiledWithIvy],
+    factory: function CompiledWithIvyModule_Factory() { return new CompiledWithIvyModule(); }
+  });
+  // /NORMATIVE
+}
+
+/**
+ * Below is a function which should be generated right next to the `@NgModule` which
+ * imports types which have `.metadata.json` files.
+ *
+ * # JIT Mode
+ * - Because the `ngPatch_CompiledWithIvyModule` is invoked all parts get patched.
+ *
+ * # AOT Mode
+ * - Build Optimizer detects `@__BUILD_OPTIMIZER_COLOCATE__` annotation and moves the
+ * code from the current location to the destination.
+ * - The resulting `ngPatch_CompiledWithIvyModule` becomes empty and eligible for tree-shaking.
+ * - Uglify removes the `ngPatch_CompiledWithIvyModule` since it is empty.
+ *
+ * # AOT Closure Mode
+ * - Option A: not supported. (Preferred option)
+ *   - Externally very few people use closure they will just have to wait until all of their
+ *     libraries are Ivy.
+ *   - Internally (g3) we build from source hence everyone switches to Ivy at the same time.
+ * - Option B: Write a closure pass similar to Build Optimizer which would move the code.
+ */
+// NORMATIVE
+ngPatch_depsOf_CompiledWithIvyModule();
+function ngPatch_depsOf_CompiledWithIvyModule() {
+  ngPatch_node_modules_some_library_path_public_CompileWithIvy();
+}
+function ngPatch_node_modules_some_library_path_public_CompileWithIvy() {
+  /** @__BUILD_OPTIMIZER_COLOCATE__ */
+  (ThirdPartyClass as any).ngInjectableDef = pending_pull_22005.defineInjectable(
+      {factory: function CompileWithIvy_Factory() { return new ThirdPartyClass(); }});
+}
+// /NORMATIVE