feat(router): allow guards and resolvers to be plain functions (#46684)

The current Router APIs require guards/resolvers to be present in the DI tree. This is because we want to treat all guards/resolvers equally and some may require dependencies. This requirement results in quite a lot of boilerplate for guards. Here are two examples:

```
const MY_GUARD = new InjectionToken<any>('my_guard');
…
providers: {provide: MY_GUARD, useValue: () => window.someGlobalState}
…
const route = {path: 'somePath', canActivate: [MY_GUARD]}
```

```
@Injectable({providedIn: 'root'})
export class MyGuardWithDependency {
  constructor(private myDep: MyDependency) {}

  canActivate() {
    return myDep.canActivate();
  }
}
…
const route = {path: 'somePath', canActivate: [MyGuardWithDependency]}
```

Notice that even when we want to write a simple guard that has no dependencies as in the first example, we still have to write either an InjectionToken or an Injectable class.

With this commit router guards and resolvers can be plain old functions.
 For example:

```
const route = {path: 'somePath', component: EditCmp, canDeactivate: [(component: EditCmp) => !component.hasUnsavedChanges]}
```

Additionally, these functions can still use Angular DI with `inject` from `@angular/core`.

```
const route = {path: 'somePath', canActivate: [() => inject(MyDependency).canActivate()]}
```

PR Close #46684

goldens/public-api/router/index.md

@@ -125,18 +125,30 @@ export interface CanActivateChild {
     canActivateChild(childRoute: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree;
 }
 
+// @public
+export type CanActivateChildFn = (childRoute: ActivatedRouteSnapshot, state: RouterStateSnapshot) => Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree;
+
+// @public
+export type CanActivateFn = (route: ActivatedRouteSnapshot, state: RouterStateSnapshot) => Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree;
+
 // @public
 export interface CanDeactivate<T> {
     // (undocumented)
     canDeactivate(component: T, currentRoute: ActivatedRouteSnapshot, currentState: RouterStateSnapshot, nextState?: RouterStateSnapshot): Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree;
 }
 
+// @public
+export type CanDeactivateFn<T> = (component: T, currentRoute: ActivatedRouteSnapshot, currentState: RouterStateSnapshot, nextState?: RouterStateSnapshot) => Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree;
+
 // @public
 export interface CanLoad {
     // (undocumented)
     canLoad(route: Route, segments: UrlSegment[]): Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree;
 }
 
+// @public
+export type CanLoadFn = (route: Route, segments: UrlSegment[]) => Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree;
+
 // @public
 export interface CanMatch {
     // (undocumented)
@@ -505,7 +517,7 @@ export interface Resolve<T> {
 
 // @public
 export type ResolveData = {
-    [key: string | symbol]: any;
+    [key: string | symbol]: any | ResolveFn<unknown>;
 };
 
 // @public
@@ -525,6 +537,9 @@ export class ResolveEnd extends RouterEvent {
     urlAfterRedirects: string;
 }
 
+// @public
+export type ResolveFn<T> = (route: ActivatedRouteSnapshot, state: RouterStateSnapshot) => Observable<T> | Promise<T> | T;
+
 // @public
 export class ResolveStart extends RouterEvent {
     constructor(
@@ -544,11 +559,11 @@ export class ResolveStart extends RouterEvent {
 
 // @public
 export interface Route {
-    canActivate?: any[];
-    canActivateChild?: any[];
-    canDeactivate?: any[];
-    canLoad?: any[];
-    canMatch?: Array<Type<CanMatch> | InjectionToken<CanMatchFn>>;
+    canActivate?: Array<CanActivateFn | any>;
+    canActivateChild?: Array<CanActivateChildFn | any>;
+    canDeactivate?: Array<CanDeactivateFn<any> | any>;
+    canLoad?: Array<CanLoadFn | any>;
+    canMatch?: Array<Type<CanMatch> | InjectionToken<CanMatchFn> | CanMatchFn>;
     children?: Routes;
     component?: Type<any>;
     data?: Data;
@@ -562,7 +577,7 @@ export interface Route {
     redirectTo?: string;
     resolve?: ResolveData;
     runGuardsAndResolvers?: RunGuardsAndResolvers;
-    title?: string | Type<Resolve<string>>;
+    title?: string | Type<Resolve<string>> | ResolveFn<string>;
 }
 
 // @public

goldens/size-tracking/integration-payloads.json

@@ -33,7 +33,7 @@
   "cli-hello-world-lazy": {
     "uncompressed": {
       "runtime": 2835,
-      "main": 238214,
+      "main": 238737,
       "polyfills": 33842,
       "src_app_lazy_lazy_module_ts": 780
     }

packages/core/src/application_ref.ts

@@ -34,10 +34,10 @@ import {InternalViewRef, ViewRef} from './linker/view_ref';
 import {isComponentResourceResolutionQueueEmpty, resolveComponentResources} from './metadata/resource_loading';
 import {assertNgModuleType} from './render3/assert';
 import {ComponentFactory as R3ComponentFactory} from './render3/component_ref';
+import {isStandalone} from './render3/definition';
 import {assertStandaloneComponentType} from './render3/errors';
 import {setLocaleId} from './render3/i18n/i18n_locale_id';
 import {setJitOptions} from './render3/jit/jit_options';
-import {isStandalone} from './render3/jit/module';
 import {createEnvironmentInjector, NgModuleFactory as R3NgModuleFactory} from './render3/ng_module_ref';
 import {publishDefaultGlobalUtils as _publishDefaultGlobalUtils} from './render3/util/global_utils';
 import {TESTABILITY} from './testability/testability';

packages/core/src/core_render3_private_export.ts

@@ -24,6 +24,7 @@ export {
 export {
   NG_INJ_DEF as ɵNG_INJ_DEF,
   NG_PROV_DEF as ɵNG_PROV_DEF,
+  isInjectable as ɵisInjectable,
 } from './di/interface/defs';
 export {createInjector as ɵcreateInjector} from './di/create_injector';
 export {
@@ -252,9 +253,7 @@ export {
 export {
   compilePipe as ɵcompilePipe,
 } from './render3/jit/pipe';
-export {
-  isStandalone as ɵisStandalone,
-} from './render3/jit/module';
+export { isStandalone as ɵisStandalone} from './render3/definition';
 export { Profiler as ɵProfiler, ProfilerEvent as ɵProfilerEvent } from './render3/profiler';
 export {
   publishDefaultGlobalUtils as ɵpublishDefaultGlobalUtils

packages/core/src/di/interface/defs.ts

@@ -190,6 +190,10 @@ export function getInjectableDef<T>(type: any): ɵɵInjectableDeclaration<T>|nul
   return getOwnDefinition(type, NG_PROV_DEF) || getOwnDefinition(type, NG_INJECTABLE_DEF);
 }
 
+export function isInjectable(type: any): boolean {
+  return getInjectableDef(type) !== null;
+}
+
 /**
  * Return definition only if it is defined directly on `type` and is not inherited from a base
  * class of `type`.

packages/core/src/render3/definition.ts

@@ -7,6 +7,7 @@
  */
 
 import {ChangeDetectionStrategy} from '../change_detection/constants';
+import {NG_PROV_DEF} from '../di/interface/defs';
 import {Mutable, Type} from '../interface/type';
 import {NgModuleDef, NgModuleType} from '../metadata/ng_module_def';
 import {SchemaMetadata} from '../metadata/schema';
@@ -743,6 +744,11 @@ export function getPipeDef<T>(type: any): PipeDef<T>|null {
   return type[NG_PIPE_DEF] || null;
 }
 
+export function isStandalone<T>(type: Type<T>): boolean {
+  const def = getComponentDef(type) || getDirectiveDef(type) || getPipeDef(type);
+  return def !== null ? def.standalone : false;
+}
+
 export function getNgModuleDef<T>(type: any, throwNotFound: true): NgModuleDef<T>;
 export function getNgModuleDef<T>(type: any): NgModuleDef<T>|null;
 export function getNgModuleDef<T>(type: any, throwNotFound?: boolean): NgModuleDef<T>|null {

packages/core/src/render3/jit/module.ts

@@ -19,7 +19,7 @@ import {NgModuleDef, NgModuleTransitiveScopes, NgModuleType} from '../../metadat
 import {deepForEach, flatten} from '../../util/array_utils';
 import {assertDefined} from '../../util/assert';
 import {EMPTY_ARRAY} from '../../util/empty';
-import {getComponentDef, getDirectiveDef, getNgModuleDef, getPipeDef} from '../definition';
+import {getComponentDef, getDirectiveDef, getNgModuleDef, getPipeDef, isStandalone} from '../definition';
 import {NG_COMP_DEF, NG_DIR_DEF, NG_FACTORY_DEF, NG_MOD_DEF, NG_PIPE_DEF} from '../fields';
 import {ComponentDef} from '../interfaces/definition';
 import {maybeUnwrapFn} from '../util/misc_utils';
@@ -197,11 +197,6 @@ export function compileNgModuleDefs(
   });
 }
 
-export function isStandalone<T>(type: Type<T>) {
-  const def = getComponentDef(type) || getDirectiveDef(type) || getPipeDef(type);
-  return def !== null ? def.standalone : false;
-}
-
 export function generateStandaloneInDeclarationsError(type: Type<any>, location: string) {
   const prefix = `Unexpected "${stringifyForError(type)}" found in the "declarations" array of the`;
   const suffix = `"${stringifyForError(type)}" is marked as standalone and can't be declared ` +

packages/core/test/bundling/router/bundle.golden_symbols.json

@@ -1314,7 +1314,7 @@
     "name": "getTView"
   },
   {
-    "name": "getToken"
+    "name": "getTokenOrFunctionIdentity"
   },
   {
     "name": "getViewRefs"

packages/router/src/index.ts

@@ -12,7 +12,7 @@ export {RouterLink, RouterLinkWithHref} from './directives/router_link';
 export {RouterLinkActive} from './directives/router_link_active';
 export {RouterOutlet, RouterOutletContract} from './directives/router_outlet';
 export {ActivationEnd, ActivationStart, ChildActivationEnd, ChildActivationStart, Event, EventType, GuardsCheckEnd, GuardsCheckStart, NavigationCancel, NavigationCancellationCode as NavigationCancellationCode, NavigationEnd, NavigationError, NavigationStart, ResolveEnd, ResolveStart, RouteConfigLoadEnd, RouteConfigLoadStart, RouterEvent, RoutesRecognized, Scroll} from './events';
-export {CanActivate, CanActivateChild, CanDeactivate, CanLoad, CanMatch, CanMatchFn, Data, LoadChildren, LoadChildrenCallback, NavigationBehaviorOptions, QueryParamsHandling, Resolve, ResolveData, Route, Routes, RunGuardsAndResolvers, UrlMatcher, UrlMatchResult} from './models';
+export {CanActivate, CanActivateChild, CanActivateChildFn, CanActivateFn, CanDeactivate, CanDeactivateFn, CanLoad, CanLoadFn, CanMatch, CanMatchFn, Data, LoadChildren, LoadChildrenCallback, NavigationBehaviorOptions, QueryParamsHandling, Resolve, ResolveData, ResolveFn, Route, Routes, RunGuardsAndResolvers, UrlMatcher, UrlMatchResult} from './models';
 export {DefaultTitleStrategy, TitleStrategy} from './page_title_strategy';
 export {BaseRouteReuseStrategy, DetachedRouteHandle, RouteReuseStrategy} from './route_reuse_strategy';
 export {Navigation, NavigationExtras, Router, UrlCreationOptions} from './router';