fix(compiler): work well with `forwardRef` with `useValue` / `useFactory`

The new expression lowering lowers everything after `useValue` / `useFactory`
into a separate exported variable. If the value was a `forwardRef`, this
was passed to the runtime and resulted in errors.

This change unwraps `forwardRef`s during runtime again.

Note: we can’t unwrap the `forwardRef` into an exported variable
during compile time, as this would defeat the purpose of the
`forwardRef` in referring to something that can’t be referred to
at this position.

packages/compiler-cli/integrationtest/src/features.ts

@@ -7,7 +7,7 @@
  */
 
 import * as common from '@angular/common';
-import {CUSTOM_ELEMENTS_SCHEMA, Component, Directive, EventEmitter, Inject, InjectionToken, NgModule, Output} from '@angular/core';
+import {CUSTOM_ELEMENTS_SCHEMA, Component, Directive, EventEmitter, Inject, InjectionToken, NgModule, Output, forwardRef} from '@angular/core';
 import {Observable} from 'rxjs/Observable';
 
 import {wrapInArray} from './funcs';
@@ -18,7 +18,7 @@ export const SOME_INJECTON_TOKEN = new InjectionToken('injectionToken');
   selector: 'comp-providers',
   template: '',
   providers: [
-    {provide: 'strToken', useValue: 'strValue'},
+    {provide: 'strToken', useValue: forwardRef(() => 'strValue')},
     {provide: SOME_INJECTON_TOKEN, useValue: 10},
     {provide: 'reference', useValue: common.NgIf},
     {provide: 'complexToken', useValue: {a: 1, b: ['test', SOME_INJECTON_TOKEN]}},

packages/compiler-cli/integrationtest/src/module.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {ApplicationRef, NgModule} from '@angular/core';
+import {ApplicationRef, NgModule, forwardRef} from '@angular/core';
 import {FormsModule} from '@angular/forms';
 import {MATERIAL_SANITY_CHECKS, MdButtonModule} from '@angular/material';
 import {ServerModule} from '@angular/platform-server';
@@ -68,7 +68,7 @@ export {SomeModule as JitSummariesSomeModule} from './jit_summaries';
   ],
   providers: [
     SomeService,
-    {provide: CUSTOM, useValue: {name: 'some name'}},
+    {provide: CUSTOM, useValue: forwardRef(() => ({name: 'some name'}))},
     // disable sanity check for material because it throws an error when used server-side
     // see https://github.com/angular/material2/issues/6292
     {provide: MATERIAL_SANITY_CHECKS, useValue: false},

packages/compiler-cli/integrationtest/test/forward_ref_spec.ts

@@ -0,0 +1,29 @@
+/**
+ * @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 './init';
+
+import * as fs from 'fs';
+import * as path from 'path';
+
+import {CUSTOM} from '../src/custom_token';
+import {CompWithProviders} from '../src/features';
+import {MainModule} from '../src/module';
+
+import {createComponent, createModule} from './util';
+
+describe('template codegen output', () => {
+  it('should support forwardRef with useValue in components', () => {
+    const compFixture = createComponent(CompWithProviders);
+    expect(compFixture.componentInstance.ctxProp).toBe('strValue');
+  });
+
+  it('should support forwardRef with useValue in modules', () => {
+    const modRef = createModule();
+    expect(modRef.injector.get(CUSTOM).name).toBe('some name');
+  });
+});

packages/core/src/view/ng_module.ts

@@ -6,6 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import {resolveForwardRef} from '../di/forward_ref';
 import {Injector, THROW_IF_NOT_FOUND} from '../di/injector';
 import {NgModuleRef} from '../linker/ng_module_factory';
 
@@ -20,6 +21,10 @@ const NgModuleRefTokenKey = tokenKey(NgModuleRef);
 export function moduleProvideDef(
     flags: NodeFlags, token: any, value: any,
     deps: ([DepFlags, any] | any)[]): NgModuleProviderDef {
+  // Need to resolve forwardRefs as e.g. for `useValue` we
+  // lowered the expression and then stopped evaluating it,
+  // i.e. also didn't unwrap it.
+  value = resolveForwardRef(value);
   const depDefs = splitDepsDsl(deps);
   return {
     // will bet set by the module definition

packages/core/src/view/provider.ts

@@ -7,7 +7,7 @@
  */
 
 import {ChangeDetectorRef, SimpleChange, SimpleChanges, WrappedValue} from '../change_detection/change_detection';
-import {Injector} from '../di';
+import {Injector, resolveForwardRef} from '../di';
 import {ElementRef} from '../linker/element_ref';
 import {TemplateRef} from '../linker/template_ref';
 import {ViewContainerRef} from '../linker/view_container_ref';
@@ -77,6 +77,10 @@ export function _def(
   if (!bindings) {
     bindings = [];
   }
+  // Need to resolve forwardRefs as e.g. for `useValue` we
+  // lowered the expression and then stopped evaluating it,
+  // i.e. also didn't unwrap it.
+  value = resolveForwardRef(value);
 
   const depDefs = splitDepsDsl(deps);