fix(di): add better type information to injector.get()

BREAKING CHANGE:

- `injector.get()` is now parameterize and returns a type based on args.
  - `injector.get(Foo)` returns an instance of `Foo`
  - `injector.get(new OpaqueToken<Foo>(‘Foo’))` returns an instance of
    `Foo`.
- OpaqueToken is now parameterized.

Migration
- If you declare your own `OpaqueToken`, it must now be parameterized.
- In the past it was possible that the injector token could return a
  type other than itself. For example
  `var cars: Car[] = injector.get(Car)` because the provider for `Car`
  was declared `multi: true`. This is now no longer possible and it is
  considered a bad form. Proper way to do this is through
  `var CARS = new OpaqueToken<Car[]>;` and then
  `var cars = injector.get(CARS)`.
- `var foo: any = injector.get(‘something’)` is still supported and
  results in `any` type, but it’s use is strongly discouraged.

modules/@angular/common/src/location/location_strategy.ts

@@ -61,4 +61,4 @@ export abstract class LocationStrategy {
  *
  * @stable
  */
-export const APP_BASE_HREF: OpaqueToken = new OpaqueToken('appBaseHref');
+export const APP_BASE_HREF = new OpaqueToken<string>('appBaseHref');

modules/@angular/compiler/src/url_resolver.ts

@@ -6,12 +6,13 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Inject, PACKAGE_ROOT_URL} from '@angular/core';
+import {Inject, OpaqueToken, PACKAGE_ROOT_URL} from '@angular/core';
 
 import {isBlank, isPresent} from './facade/lang';
 import {CompilerInjectable} from './injectable';
 
 
+
 /**
  * Create a {@link UrlResolver} with no package prefix.
  */

modules/@angular/core/src/application_ref.ts

@@ -83,7 +83,7 @@ export function createPlatform(injector: Injector): PlatformRef {
         'There can be only one platform. Destroy the previous one to create a new one.');
   }
   _platform = injector.get(PlatformRef);
-  const inits: Function[] = <Function[]>injector.get(PLATFORM_INITIALIZER, null);
+  const inits = injector.get(PLATFORM_INITIALIZER, null);
   if (inits) inits.forEach(init => init());
   return _platform;
 }
@@ -413,7 +413,7 @@ export class ApplicationRef_ extends ApplicationRef {
   /** @internal */
   static _tickScope: WtfScopeFn = wtfCreateScope('ApplicationRef#tick()');
 
-  private _bootstrapListeners: Function[] = [];
+  private _bootstrapListeners: ((compRef: ComponentRef<any>) => void)[] = [];
   private _rootComponents: ComponentRef<any>[] = [];
   private _rootComponentTypes: Type<any>[] = [];
   private _views: AppView<any>[] = [];
@@ -480,8 +480,7 @@ export class ApplicationRef_ extends ApplicationRef {
     this._rootComponents.push(componentRef);
     // Get the listeners lazily to prevent DI cycles.
     const listeners =
-        <((compRef: ComponentRef<any>) => void)[]>this._injector.get(APP_BOOTSTRAP_LISTENER, [])
-            .concat(this._bootstrapListeners);
+        this._injector.get(APP_BOOTSTRAP_LISTENER, []).concat(this._bootstrapListeners);
     listeners.forEach((listener) => listener(componentRef));
   }
 

modules/@angular/core/src/application_tokens.ts

@@ -7,6 +7,7 @@
  */
 
 import {OpaqueToken} from './di';
+import {ComponentRef} from './linker/component_factory';
 
 
 /**
@@ -43,7 +44,7 @@ function _randomChar(): string {
  * A function that will be executed when a platform is initialized.
  * @experimental
  */
-export const PLATFORM_INITIALIZER: any = new OpaqueToken('Platform Initializer');
+export const PLATFORM_INITIALIZER = new OpaqueToken<(() => void)[]>('Platform Initializer');
 
 /**
  * All callbacks provided via this token will be called for every component that is bootstrapped.
@@ -53,10 +54,11 @@ export const PLATFORM_INITIALIZER: any = new OpaqueToken('Platform Initializer')
  *
  * @experimental
  */
-export const APP_BOOTSTRAP_LISTENER = new OpaqueToken('appBootstrapListener');
+export const APP_BOOTSTRAP_LISTENER =
+    new OpaqueToken<((compRef: ComponentRef<any>) => void)[]>('appBootstrapListener');
 
 /**
  * A token which indicates the root directory of the application
  * @experimental
  */
-export const PACKAGE_ROOT_URL: any = new OpaqueToken('Application Packages Root URL');
+export const PACKAGE_ROOT_URL = new OpaqueToken<string>('Application Packages Root URL');

modules/@angular/core/src/di/injector.ts

@@ -8,6 +8,9 @@
 
 import {unimplemented} from '../facade/errors';
 import {stringify} from '../facade/lang';
+import {Type} from '../type';
+
+import {OpaqueToken} from './opaque_token';
 
 const _THROW_IF_NOT_FOUND = new Object();
 export const THROW_IF_NOT_FOUND = _THROW_IF_NOT_FOUND;
@@ -52,5 +55,7 @@ export abstract class Injector {
    * Injector.THROW_IF_NOT_FOUND is given
    * - Returns the `notFoundValue` otherwise
    */
+  get<T>(token: Type<T>|OpaqueToken<T>, notFoundValue?: T): T;
+  get(token: any, notFoundValue?: any): any;
   get(token: any, notFoundValue?: any): any { return unimplemented(); }
 }

modules/@angular/core/src/di/opaque_token.ts

@@ -28,7 +28,7 @@
  * error messages.
  * @stable
  */
-export class OpaqueToken {
+export class OpaqueToken<T> {
   constructor(private _desc: string) {}
 
   toString(): string { return `Token ${this._desc}`; }

modules/@angular/core/test/linker/ng_module_integration_spec.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {ANALYZE_FOR_ENTRY_COMPONENTS, CUSTOM_ELEMENTS_SCHEMA, Compiler, Component, ComponentFactoryResolver, Directive, HostBinding, Inject, Injectable, Injector, Input, NgModule, NgModuleRef, Optional, Pipe, Provider, Self, Type, forwardRef, getModuleFactory} from '@angular/core';
+import {ANALYZE_FOR_ENTRY_COMPONENTS, CUSTOM_ELEMENTS_SCHEMA, Compiler, Component, ComponentFactoryResolver, Directive, HostBinding, Inject, Injectable, Injector, Input, NgModule, NgModuleRef, OpaqueToken, Optional, Pipe, Provider, Self, Type, forwardRef, getModuleFactory} from '@angular/core';
 import {Console} from '@angular/core/src/console';
 import {ComponentFixture, TestBed, inject} from '@angular/core/testing';
 import {expect} from '@angular/platform-browser/testing/matchers';
@@ -30,6 +30,7 @@ class Dashboard {
 
 class TurboEngine extends Engine {}
 
+const CARS = new OpaqueToken<Car[]>('Cars');
 @Injectable()
 class Car {
   engine: Engine;
@@ -692,21 +693,21 @@ function declareTests({useJit}: {useJit: boolean}) {
 
       it('should support multiProviders', () => {
         const injector = createInjector([
-          Engine, {provide: Car, useClass: SportsCar, multi: true},
-          {provide: Car, useClass: CarWithOptionalEngine, multi: true}
+          Engine, {provide: CARS, useClass: SportsCar, multi: true},
+          {provide: CARS, useClass: CarWithOptionalEngine, multi: true}
         ]);
 
-        const cars = injector.get(Car);
+        const cars = injector.get(CARS);
         expect(cars.length).toEqual(2);
         expect(cars[0]).toBeAnInstanceOf(SportsCar);
         expect(cars[1]).toBeAnInstanceOf(CarWithOptionalEngine);
       });
 
       it('should support multiProviders that are created using useExisting', () => {
         const injector = createInjector(
-            [Engine, SportsCar, {provide: Car, useExisting: SportsCar, multi: true}]);
+            [Engine, SportsCar, {provide: CARS, useExisting: SportsCar, multi: true}]);
 
-        const cars = injector.get(Car);
+        const cars = injector.get(CARS);
         expect(cars.length).toEqual(1);
         expect(cars[0]).toBe(injector.get(SportsCar));
       });

modules/@angular/forms/src/directives/control_value_accessor.ts

@@ -49,4 +49,4 @@ export interface ControlValueAccessor {
  * See {@link DefaultValueAccessor} for how to implement one.
  * @stable
  */
-export const NG_VALUE_ACCESSOR: OpaqueToken = new OpaqueToken('NgValueAccessor');
+export const NG_VALUE_ACCESSOR = new OpaqueToken<ControlValueAccessor>('NgValueAccessor');

modules/@angular/forms/src/directives/shared.ts

@@ -116,12 +116,11 @@ function _throwError(dir: AbstractControlDirective, message: string): void {
   throw new Error(`${message} ${messageEnd}`);
 }
 
-export function composeValidators(validators: /* Array<Validator|Function> */ any[]): ValidatorFn {
+export function composeValidators(validators: Array<Validator|Function>): ValidatorFn {
   return isPresent(validators) ? Validators.compose(validators.map(normalizeValidator)) : null;
 }
 
-export function composeAsyncValidators(validators: /* Array<Validator|Function> */ any[]):
-    AsyncValidatorFn {
+export function composeAsyncValidators(validators: Array<Validator|Function>): AsyncValidatorFn {
   return isPresent(validators) ? Validators.composeAsync(validators.map(normalizeAsyncValidator)) :
                                  null;
 }

modules/@angular/forms/src/validators.ts

@@ -8,7 +8,7 @@
 
 import {OpaqueToken} from '@angular/core';
 import {toPromise} from 'rxjs/operator/toPromise';
-import {AsyncValidatorFn, ValidatorFn} from './directives/validators';
+import {AsyncValidatorFn, ValidatorFn, Validator} from './directives/validators';
 import {StringMapWrapper} from './facade/collection';
 import {isPresent} from './facade/lang';
 import {AbstractControl} from './model';
@@ -28,7 +28,7 @@ function isEmptyInputValue(value: any) {
  * {@example core/forms/ts/ng_validators/ng_validators.ts region='ng_validators'}
  * @stable
  */
-export const NG_VALIDATORS: OpaqueToken = new OpaqueToken('NgValidators');
+export const NG_VALIDATORS = new OpaqueToken<Array<Validator|Function>>('NgValidators');
 
 /**
  * Providers for asynchronous validators to be used for {@link FormControl}s
@@ -40,7 +40,7 @@ export const NG_VALIDATORS: OpaqueToken = new OpaqueToken('NgValidators');
  *
  * @stable
  */
-export const NG_ASYNC_VALIDATORS: OpaqueToken = new OpaqueToken('NgAsyncValidators');
+export const NG_ASYNC_VALIDATORS = new OpaqueToken<Array<Validator|Function>>('NgAsyncValidators');
 
 /**
  * Provides a set of validators used by form controls.

modules/@angular/http/test/http_spec.ts

@@ -42,8 +42,8 @@ export function main() {
 
          http = injector.get(Http);
          jsonp = injector.get(Jsonp);
-         jsonpBackend = injector.get(JSONPBackend);
-         xhrBackend = injector.get(XHRBackend);
+         jsonpBackend = injector.get(JSONPBackend) as MockBackend;
+         xhrBackend = injector.get(XHRBackend) as any as MockBackend;
 
          let xhrCreatedConnections = 0;
          let jsonpCreatedConnections = 0;

modules/@angular/platform-browser/src/dom/dom_tokens.ts

@@ -16,4 +16,4 @@ import {OpaqueToken} from '@angular/core';
  *
  * @stable
  */
-export const DOCUMENT: OpaqueToken = new OpaqueToken('DocumentToken');
+export const DOCUMENT = new OpaqueToken<Document>('DocumentToken');

modules/@angular/platform-browser/src/dom/events/event_manager.ts

@@ -12,7 +12,7 @@ import {getDOM} from '../dom_adapter';
 /**
  * @stable
  */
-export const EVENT_MANAGER_PLUGINS: OpaqueToken = new OpaqueToken('EventManagerPlugins');
+export const EVENT_MANAGER_PLUGINS = new OpaqueToken<EventManagerPlugin[]>('EventManagerPlugins');
 
 /**
  * @stable

modules/@angular/platform-browser/src/dom/events/hammer_gestures.ts

@@ -53,7 +53,7 @@ const EVENT_NAMES = {
  *
  * @experimental
  */
-export const HAMMER_GESTURE_CONFIG: OpaqueToken = new OpaqueToken('HammerGestureConfig');
+export const HAMMER_GESTURE_CONFIG = new OpaqueToken<HammerGestureConfig>('HammerGestureConfig');
 
 export interface HammerInstance {
   on(eventName: string, callback: Function): void;

modules/@angular/platform-webworker/src/worker_render.ts

@@ -42,7 +42,7 @@ export class WebWorkerInstance {
 /**
  * @experimental WebWorker support is currently experimental.
  */
-export const WORKER_SCRIPT: OpaqueToken = new OpaqueToken('WebWorkerScript');
+export const WORKER_SCRIPT = new OpaqueToken<string>('WebWorkerScript');
 
 /**
  * A multi-provider used to automatically call the `start()` method after the service is
@@ -52,7 +52,7 @@ export const WORKER_SCRIPT: OpaqueToken = new OpaqueToken('WebWorkerScript');
  * @experimental WebWorker support is currently experimental.
  */
 export const WORKER_UI_STARTABLE_MESSAGING_SERVICE =
-    new OpaqueToken('WorkerRenderStartableMsgService');
+    new OpaqueToken<MessageBasedRenderer[]>('WorkerRenderStartableMsgService');
 
 export const _WORKER_UI_PLATFORM_PROVIDERS: Provider[] = [
   {provide: NgZone, useFactory: createNgZone, deps: []},

modules/@angular/router/src/router_config_loader.ts

@@ -19,7 +19,7 @@ import {flatten, wrapIntoObservable} from './utils/collection';
 /**
  * @experimental
  */
-export const ROUTES = new OpaqueToken('ROUTES');
+export const ROUTES = new OpaqueToken<Route[][]>('ROUTES');
 
 export class LoadedRouterConfig {
   constructor(

modules/@angular/router/upgrade.ts

@@ -57,7 +57,7 @@ export function initialRouterNavigation(
     const router = ngUpgrade.injector.get(Router);
     const ref = ngUpgrade.injector.get(ApplicationRef);
 
-    router.resetRootComponentType(ref.componentTypes[0]);
+    (router as any).resetRootComponentType(ref.componentTypes[0]);
     preloader.setUpPreloading();
     if (opts.initialNavigation === false) {
       router.setUpLocationChangeListener();
@@ -86,4 +86,4 @@ export function setUpLocationSync(ngUpgrade: UpgradeModule): void {
         url.href = next;
         router.navigateByUrl(url.pathname);
       });
-}
+}