fix(router): fix change in behaviour on load error occur

Clear the stored loader promise so that subsequent load will try the fetch again. The restores the same behaviour as before we cached the loader to fix angular#26557
pgammans · Apr 23, 2020 · f626b19 · f626b19
1 parent 39afc02
commit f626b19
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diff --git a/packages/router/src/router_config_loader.ts b/packages/router/src/router_config_loader.ts
@@ -8,7 +8,7 @@
 
 import {Compiler, InjectionToken, Injector, NgModuleFactory, NgModuleFactoryLoader} from '@angular/core';
 import {from, Observable, of} from 'rxjs';
-import {map, mergeMap, share, tap} from 'rxjs/operators';
+import {catchError, map, mergeMap, share} from 'rxjs/operators';
 
 import {LoadChildren, LoadedRouterConfig, Route, standardizeConfig} from './config';
 import {flatten, wrapIntoObservable} from './utils/collection';
@@ -35,6 +35,10 @@ export class RouterConfigLoader {
       const moduleFactory$ = this.loadModuleFactory(route.loadChildren!);
 
       route._loader$ = moduleFactory$.pipe(
+          catchError((err) => {
+            route._loader$ = undefined;
+            throw err;
+          }),
           map((factory: NgModuleFactory<any>) => {
             if (this.onLoadEndListener) {
               this.onLoadEndListener(route);

diff --git a/packages/router/test/router_preloader.spec.ts b/packages/router/test/router_preloader.spec.ts
@@ -7,6 +7,7 @@
  */
 
 import {Compiler, Component, NgModule, NgModuleFactoryLoader, NgModuleRef} from '@angular/core';
+import {resolveComponentResources} from '@angular/core/src/metadata/resource_loading';
 import {fakeAsync, inject, TestBed, tick} from '@angular/core/testing';
 import {PreloadAllModules, PreloadingStrategy, RouterPreloader} from '@angular/router';
 import {BehaviorSubject, Observable, of} from 'rxjs';
@@ -316,6 +317,58 @@ describe('RouterPreloader', () => {
              ]);
            })));
 
+    it('and cope with the loader throwing exceptions',
+       fakeAsync(inject(
+           [NgModuleFactoryLoader, RouterPreloader, Router, NgModuleRef, Compiler],
+           (loader: SpyNgModuleFactoryLoader, preloader: RouterPreloader, router: Router,
+            testModule: NgModuleRef<any>, compiler: Compiler) => {
+             router.events.subscribe(e => {
+               if (e instanceof RouteConfigLoadEnd || e instanceof RouteConfigLoadStart) {
+                 events.push(e);
+               }
+             });
+
+             loader.stubbedModules = {
+               'expectedreload#error:1:Fake module load error (expectedreload)': LoadedModule1,
+               submodule: LoadedModule2
+             };
+
+             let loadedConfig: LoadedRouterConfig;
+             const c = router.config;
+             expect(c[0].loadChildren).toEqual('expectedreload');
+             loadedConfig = (c[0] as any)._loadedConfig;
+             expect(loadedConfig).toBeUndefined();
+
+             preloader.preload().subscribe((x) => {});
+
+             tick();
+             loadedConfig = (c[0] as any)._loadedConfig;
+             expect(loadedConfig).toBeUndefined();
+             expect(logMessages).toEqual([
+               'Add route loader for expectedreload',
+               'list changed: ',
+             ]);
+
+             router.navigateByUrl('/lazy/LoadedModule1').catch((reason) => {
+               expect(reason).toEqual(Error('Fake module load error (expectedreload)'));
+             });
+             tick();
+             loadedConfig = (c[0] as any)._loadedConfig;
+             expect(loadedConfig).toBeUndefined();
+             expect((c[0] as any)._loader$).toBeUndefined();
+
+             router.navigateByUrl('/lazy/LoadedModule1').catch(() => {
+               expect('Not to get here').toBeUndefined('Not to throw');
+             });
+             tick();
+
+             expect(events.map(e => e.toString())).toEqual([
+               'RouteConfigLoadStart(path: lazy)', 'RouteConfigLoadStart(path: lazy)',
+               'RouteConfigLoadEnd(path: lazy)'
+             ]);
+           })));
+
+
     it('without autoloading loading submodules',
        fakeAsync(inject(
            [NgModuleFactoryLoader, RouterPreloader, Router, NgModuleRef, Compiler],