From 74ff1ed8ea97ef554ac8c9bf8dd53ec9e7c5da2e Mon Sep 17 00:00:00 2001
From: Silke <s.grueber@intershop.de>
Date: Fri, 9 Jun 2023 12:47:31 +0200
Subject: [PATCH 1/8] feat: save language selection as cookie

---
 docs/guides/cookie-consent.md                     | 13 +++++++------
 .../language-switch.component.html                |  2 +-
 .../language-switch.component.spec.ts             |  7 ++++++-
 .../language-switch/language-switch.component.ts  | 15 ++++++++++++++-
 src/environments/environment.model.ts             |  2 +-
 5 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/docs/guides/cookie-consent.md b/docs/guides/cookie-consent.md
index 1405129e81..d5e237fb85 100644
--- a/docs/guides/cookie-consent.md
+++ b/docs/guides/cookie-consent.md
@@ -33,7 +33,7 @@ cookieConsentOptions: {
       description: 'cookie.consent.option.tracking.description',
     },
   },
-  allowedCookies: ['cookieConsent', 'apiToken'],
+  allowedCookies: ['apiToken', 'cookieConsent', 'preferredLocale'],
 },
 ```
 
@@ -42,7 +42,7 @@ The `options` array configures the presented options in the _Cookie Preferences_
 - The option `id` is the value that will be stored in the user's `cookieConsent` settings.
 - The `name` makes up the checkbox label name, usually given as localization key.
 - The `description` contains the additional option description, usually given as localization key.
-- With the `required` flag, an option can be marked as not deselectable.
+- With the `required` flag, an option can be marked as not non-selectable.
   In this way, the user can be informed that necessary cookies are always set without explicit consent of the user.
 
 The following screenshot is the rendered representation of the default cookie consent options configuration:
@@ -100,10 +100,11 @@ This route can be linked to from anywhere within the application.
 
 ## PWA Required Cookies
 
-| Name          | Expiration | Provider      | Description                                                       | Category    |
-| ------------- | ---------- | ------------- | ----------------------------------------------------------------- | ----------- |
-| apiToken      | 1 year     | Intershop PWA | The API token used by the Intershop Commerce Management REST API. | First Party |
-| cookieConsent | 1 year     | Intershop PWA | Saves the user's cookie consent settings.                         | First Party |
+| Name            | Expiration | Provider      | Description                                                       | Category    |
+| --------------- | ---------- | ------------- | ----------------------------------------------------------------- | ----------- |
+| apiToken        | 1 year     | Intershop PWA | The API token used by the Intershop Commerce Management REST API. | First Party |
+| cookieConsent   | 1 year     | Intershop PWA | Saves the user's cookie consent settings.                         | First Party |
+| preferredLocale | 1 year     | Intershop PWA | Saves the user's language selection.                              | First Party |
 
 ## Disabling the Integrated Cookie Consent Handling
 
diff --git a/src/app/shell/header/language-switch/language-switch.component.html b/src/app/shell/header/language-switch/language-switch.component.html
index d2c99eea73..eadcaafe65 100644
--- a/src/app/shell/header/language-switch/language-switch.component.html
+++ b/src/app/shell/header/language-switch/language-switch.component.html
@@ -25,7 +25,7 @@
         <ul *ngIf="availableLocales.length">
           <ng-container *ngFor="let l of availableLocales">
             <li *ngIf="l !== locale">
-              <a [href]="location | makeHref : { lang: l } | async" role="menuitem">
+              <a [href]="location | makeHref : { lang: l } | async" (click)="setLocaleCookie(l)" role="menuitem">
                 {{ 'locale.' + l + '.long' | translate }}
               </a>
             </li>
diff --git a/src/app/shell/header/language-switch/language-switch.component.spec.ts b/src/app/shell/header/language-switch/language-switch.component.spec.ts
index ccc7ae3cab..8b29a2de6b 100644
--- a/src/app/shell/header/language-switch/language-switch.component.spec.ts
+++ b/src/app/shell/header/language-switch/language-switch.component.spec.ts
@@ -9,6 +9,7 @@ import { instance, mock, when } from 'ts-mockito';
 
 import { AppFacade } from 'ish-core/facades/app.facade';
 import { MakeHrefPipe } from 'ish-core/pipes/make-href.pipe';
+import { CookiesService } from 'ish-core/utils/cookies/cookies.service';
 
 import { LanguageSwitchComponent } from './language-switch.component';
 
@@ -18,6 +19,7 @@ describe('Language Switch Component', () => {
   let element: HTMLElement;
   let appFacade: AppFacade;
   const locales = ['en_US', 'de_DE', 'fr_FR'];
+  const cookiesServiceMock = mock(CookiesService);
 
   beforeEach(async () => {
     appFacade = mock(AppFacade);
@@ -29,7 +31,10 @@ describe('Language Switch Component', () => {
         MockPipe(MakeHrefPipe, (_, urlParams) => of(urlParams.lang)),
       ],
       imports: [NgbDropdownModule, TranslateModule.forRoot()],
-      providers: [{ provide: AppFacade, useFactory: () => instance(appFacade) }],
+      providers: [
+        { provide: AppFacade, useFactory: () => instance(appFacade) },
+        { provide: CookiesService, useValue: instance(cookiesServiceMock) },
+      ],
     }).compileComponents();
   });
 
diff --git a/src/app/shell/header/language-switch/language-switch.component.ts b/src/app/shell/header/language-switch/language-switch.component.ts
index 654782f655..12f4362335 100644
--- a/src/app/shell/header/language-switch/language-switch.component.ts
+++ b/src/app/shell/header/language-switch/language-switch.component.ts
@@ -3,6 +3,7 @@ import { ChangeDetectionStrategy, Component, Input, OnInit } from '@angular/core
 import { Observable } from 'rxjs';
 
 import { AppFacade } from 'ish-core/facades/app.facade';
+import { CookiesService } from 'ish-core/utils/cookies/cookies.service';
 
 @Component({
   selector: 'ish-language-switch',
@@ -19,10 +20,22 @@ export class LanguageSwitchComponent implements OnInit {
   locale$: Observable<string>;
   availableLocales$: Observable<string[]>;
 
-  constructor(private appFacade: AppFacade, public location: LocationStrategy) {}
+  constructor(
+    private appFacade: AppFacade,
+    private cookiesService: CookiesService,
+    public location: LocationStrategy
+  ) {}
 
   ngOnInit() {
     this.locale$ = this.appFacade.currentLocale$;
     this.availableLocales$ = this.appFacade.availableLocales$;
   }
+
+  setLocaleCookie(locale: string) {
+    this.cookiesService.put('preferredLocale', locale, {
+      expires: new Date(new Date().setFullYear(new Date().getFullYear() + 1)),
+      path: '/',
+    });
+    return true;
+  }
 }
diff --git a/src/environments/environment.model.ts b/src/environments/environment.model.ts
index 559c67bec3..c087fe2699 100644
--- a/src/environments/environment.model.ts
+++ b/src/environments/environment.model.ts
@@ -186,7 +186,7 @@ export const ENVIRONMENT_DEFAULTS: Omit<Environment, 'icmChannel'> = {
         description: 'cookie.consent.option.tracking.description',
       },
     },
-    allowedCookies: ['cookieConsent', 'apiToken'],
+    allowedCookies: ['apiToken', 'cookieConsent', 'preferredLocale'],
   },
   cookieConsentVersion: 1,
 

From 461b038aa26d763bd42d843d6ed00315d19e855a Mon Sep 17 00:00:00 2001
From: Silke <s.grueber@intershop.de>
Date: Mon, 12 Jun 2023 15:03:17 +0200
Subject: [PATCH 2/8] feat: use 'preferredLocale' cookie to set language after
 application start

---
 ...ge-language-authentication.b2c.e2e-spec.ts |  6 +-
 .../core/configurations/configuration.meta.ts |  6 +-
 src/app/core/pipes/make-href.pipe.spec.ts     | 16 ++--
 src/app/core/pipes/make-href.pipe.ts          | 18 +----
 src/app/core/store/core/core-store.module.ts  |  5 +-
 .../server-config.effects.spec.ts             | 78 ++++++++++++++++---
 .../server-config/server-config.effects.ts    | 38 ++++++++-
 .../multi-site/multi-site.service.spec.ts     | 27 ++++++-
 .../utils/multi-site/multi-site.service.ts    | 21 +++--
 9 files changed, 164 insertions(+), 51 deletions(-)

diff --git a/e2e/cypress/e2e/specs/system/change-language-authentication.b2c.e2e-spec.ts b/e2e/cypress/e2e/specs/system/change-language-authentication.b2c.e2e-spec.ts
index 06f949df04..6d3393a0c1 100644
--- a/e2e/cypress/e2e/specs/system/change-language-authentication.b2c.e2e-spec.ts
+++ b/e2e/cypress/e2e/specs/system/change-language-authentication.b2c.e2e-spec.ts
@@ -19,7 +19,10 @@ const _ = {
 
 describe('Language Changing User', () => {
   describe('when logged in', () => {
-    before(() => LoginPage.navigateTo());
+    before(() => {
+      cy.clearCookie('preferredLocale');
+      LoginPage.navigateTo();
+    });
 
     it('should log in', () => {
       createUserViaREST(_.user);
@@ -47,6 +50,7 @@ describe('Language Changing User', () => {
   describe('when accessing protected content without cookie', () => {
     before(() => {
       cy.clearCookie('apiToken');
+      cy.clearCookie('preferredLocale');
       MyAccountPage.navigateTo();
     });
 
diff --git a/src/app/core/configurations/configuration.meta.ts b/src/app/core/configurations/configuration.meta.ts
index 3c6ab84544..02534841fc 100644
--- a/src/app/core/configurations/configuration.meta.ts
+++ b/src/app/core/configurations/configuration.meta.ts
@@ -20,7 +20,9 @@ class SimpleParamMap {
 
 // eslint-disable-next-line complexity
 function extractConfigurationParameters(state: ConfigurationState, paramMap: SimpleParamMap) {
-  const keys: (keyof ConfigurationState)[] = ['channel', 'application', 'lang', 'currency', 'identityProvider'];
+  const keys: (keyof ConfigurationState)[] = PRODUCTION_MODE
+    ? ['lang']
+    : ['channel', 'application', 'lang', 'currency', 'identityProvider'];
   const properties: Partial<ConfigurationState> = keys
     .filter(key => paramMap.has(key) && paramMap.get(key) !== 'default')
     .map(key => ({ [key]: paramMap.get(key) }))
@@ -51,12 +53,14 @@ function extractConfigurationParameters(state: ConfigurationState, paramMap: Sim
   if (Object.keys(properties).length) {
     return configurationReducer(state, applyConfiguration(properties));
   }
+
   return state;
 }
 
 /**
  * meta reducer for overriding client side state if supplied by server
  */
+
 export function configurationMeta(reducer: ActionReducer<CoreState>): ActionReducer<CoreState> {
   let first = false;
 
diff --git a/src/app/core/pipes/make-href.pipe.spec.ts b/src/app/core/pipes/make-href.pipe.spec.ts
index c2f98e55ec..f9bceebcbd 100644
--- a/src/app/core/pipes/make-href.pipe.spec.ts
+++ b/src/app/core/pipes/make-href.pipe.spec.ts
@@ -17,8 +17,11 @@ describe('Make Href Pipe', () => {
       providers: [{ provide: MultiSiteService, useFactory: () => instance(multiSiteService) }, MakeHrefPipe],
     });
     makeHrefPipe = TestBed.inject(MakeHrefPipe);
-    when(multiSiteService.getLangUpdatedUrl(anything(), anything(), anything())).thenCall(
-      (url: string, _: LocationStrategy) => of(url)
+    when(multiSiteService.getLangUpdatedUrl(anything(), anything())).thenCall((url: string, _: LocationStrategy) =>
+      of(url)
+    );
+    when(multiSiteService.appendUrlParams(anything(), anything(), anything())).thenCall(
+      (url: string, _, __: string) => url
     );
   });
 
@@ -30,13 +33,6 @@ describe('Make Href Pipe', () => {
   it.each<any | jest.DoneCallback>([
     [undefined, undefined, 'undefined'],
     ['/test', undefined, '/test'],
-    ['/test', {}, '/test'],
-    ['/test', { foo: 'bar' }, '/test;foo=bar'],
-    ['/test', { foo: 'bar', marco: 'polo' }, '/test;foo=bar;marco=polo'],
-    ['/test?query=q', undefined, '/test?query=q'],
-    ['/test?query=q', {}, '/test?query=q'],
-    ['/test?query=q', { foo: 'bar' }, '/test;foo=bar?query=q'],
-    ['/test?query=q', { foo: 'bar', marco: 'polo' }, '/test;foo=bar;marco=polo?query=q'],
   ])(`should transform "%s" with %j to "%s"`, (url, params, expected, done: jest.DoneCallback) => {
     makeHrefPipe.transform({ path: () => url, getBaseHref: () => '/' } as LocationStrategy, params).subscribe(res => {
       expect(res).toEqual(expected);
@@ -48,7 +44,7 @@ describe('Make Href Pipe', () => {
     makeHrefPipe
       .transform({ path: () => '/de/test', getBaseHref: () => '/de' } as LocationStrategy, { lang: 'en_US' })
       .subscribe(() => {
-        verify(multiSiteService.getLangUpdatedUrl(anything(), anything(), anything())).once();
+        verify(multiSiteService.getLangUpdatedUrl(anything(), anything())).once();
         done();
       });
   });
diff --git a/src/app/core/pipes/make-href.pipe.ts b/src/app/core/pipes/make-href.pipe.ts
index 689892d36e..cc6d967583 100644
--- a/src/app/core/pipes/make-href.pipe.ts
+++ b/src/app/core/pipes/make-href.pipe.ts
@@ -21,29 +21,19 @@ export class MakeHrefPipe implements PipeTransform {
 
         if (urlParams) {
           if (urlParams.lang) {
-            return this.multiSiteService.getLangUpdatedUrl(urlParams.lang, newUrl, location.getBaseHref()).pipe(
+            return this.multiSiteService.getLangUpdatedUrl(urlParams.lang, newUrl).pipe(
               map(modifiedUrl => {
                 const modifiedUrlParams = modifiedUrl === newUrl ? urlParams : omit(urlParams, 'lang');
-                return appendUrlParams(modifiedUrl, modifiedUrlParams, split?.[1]);
+                return this.multiSiteService.appendUrlParams(modifiedUrl, modifiedUrlParams, split?.[1]);
               })
             );
           } else {
-            return of(newUrl).pipe(map(url => appendUrlParams(url, urlParams, split?.[1])));
+            return of(newUrl).pipe(map(url => this.multiSiteService.appendUrlParams(url, urlParams, split?.[1])));
           }
         } else {
-          return of(appendUrlParams(newUrl, undefined, split?.[1]));
+          return of(this.multiSiteService.appendUrlParams(newUrl, undefined, split?.[1]));
         }
       })
     );
   }
 }
-
-function appendUrlParams(url: string, urlParams: Record<string, string>, queryParams: string | undefined): string {
-  return `${url}${
-    urlParams
-      ? Object.keys(urlParams)
-          .map(k => `;${k}=${urlParams[k]}`)
-          .join('')
-      : ''
-  }${queryParams ? `?${queryParams}` : ''}`;
-}
diff --git a/src/app/core/store/core/core-store.module.ts b/src/app/core/store/core/core-store.module.ts
index 830f4786d5..12bc7e7f43 100644
--- a/src/app/core/store/core/core-store.module.ts
+++ b/src/app/core/store/core/core-store.module.ts
@@ -29,10 +29,7 @@ const coreReducers: ActionReducerMap<CoreState> = {
 
 const coreEffects = [ErrorEffects, ViewconfEffects, ConfigurationEffects, MessagesEffects, ServerConfigEffects];
 
-const coreMetaReducers: MetaReducer<CoreState>[] = [
-  ngrxStateTransferMeta,
-  ...(PRODUCTION_MODE ? [] : [configurationMeta]),
-];
+const coreMetaReducers: MetaReducer<CoreState>[] = [ngrxStateTransferMeta, configurationMeta];
 
 @NgModule({
   imports: [
diff --git a/src/app/core/store/core/server-config/server-config.effects.spec.ts b/src/app/core/store/core/server-config/server-config.effects.spec.ts
index ff2dd4ba99..4cb132a2ee 100644
--- a/src/app/core/store/core/server-config/server-config.effects.spec.ts
+++ b/src/app/core/store/core/server-config/server-config.effects.spec.ts
@@ -1,18 +1,21 @@
-import { TestBed } from '@angular/core/testing';
+import { TestBed, fakeAsync, tick } from '@angular/core/testing';
 import { provideMockActions } from '@ngrx/effects/testing';
 import { Action } from '@ngrx/store';
 import { MockStore, provideMockStore } from '@ngrx/store/testing';
 import { cold, hot } from 'jasmine-marbles';
-import { Observable, of, throwError } from 'rxjs';
-import { instance, mock, when } from 'ts-mockito';
+import { Observable, noop, of, throwError } from 'rxjs';
+import { anything, instance, mock, when } from 'ts-mockito';
 
-import { FeatureToggleModule } from 'ish-core/feature-toggle.module';
+import { ServerConfig } from 'ish-core/models/server-config/server-config.model';
 import { ConfigurationService } from 'ish-core/services/configuration/configuration.service';
+import { getCurrentLocale } from 'ish-core/store/core/configuration/configuration.selectors';
 import { CoreStoreModule } from 'ish-core/store/core/core-store.module';
 import { serverConfigError } from 'ish-core/store/core/error';
+import { CookiesService } from 'ish-core/utils/cookies/cookies.service';
 import { makeHttpError } from 'ish-core/utils/dev/api-service-utils';
 import { StoreWithSnapshots, provideStoreSnapshots } from 'ish-core/utils/dev/ngrx-testing';
 import { routerTestNavigationAction } from 'ish-core/utils/dev/routing';
+import { MultiSiteService } from 'ish-core/utils/multi-site/multi-site.service';
 
 import { loadServerConfig, loadServerConfigFail, loadServerConfigSuccess } from './server-config.actions';
 import { ServerConfigEffects } from './server-config.effects';
@@ -23,15 +26,20 @@ describe('Server Config Effects', () => {
 
   beforeEach(() => {
     const configurationServiceMock = mock(ConfigurationService);
+    const cookiesServiceMock = mock(CookiesService);
+    const multiSiteServiceMock = mock(MultiSiteService);
+
     when(configurationServiceMock.getServerConfiguration()).thenReturn(of({}));
+    when(cookiesServiceMock.get(anything())).thenReturn('de_DE');
+    when(multiSiteServiceMock.getLangUpdatedUrl(anything(), anything())).thenReturn(of('/home;lang=de_DE'));
+    when(multiSiteServiceMock.appendUrlParams(anything(), anything(), anything())).thenReturn('/home;lang=de_DE');
 
     TestBed.configureTestingModule({
-      imports: [
-        CoreStoreModule.forTesting(['serverConfig'], [ServerConfigEffects]),
-        FeatureToggleModule.forTesting('extraConfiguration'),
-      ],
+      imports: [CoreStoreModule.forTesting(['serverConfig', 'configuration'], [ServerConfigEffects])],
       providers: [
         { provide: ConfigurationService, useFactory: () => instance(configurationServiceMock) },
+        { provide: CookiesService, useFactory: () => instance(cookiesServiceMock) },
+        { provide: MultiSiteService, useFactory: () => instance(multiSiteServiceMock) },
         provideStoreSnapshots(),
       ],
     });
@@ -44,6 +52,10 @@ describe('Server Config Effects', () => {
   });
 
   it('should trigger the loading of config data on the first page', () => {
+    Object.defineProperty(window, 'location', {
+      value: { assign: jest.fn() },
+      writable: true,
+    });
     store$.dispatch(routerTestNavigationAction({ routerState: { url: '/any' } }));
 
     expect(store$.actionsArray()).toMatchInlineSnapshot(`
@@ -60,13 +72,19 @@ describe('Server Config Effects', () => {
   let effects: ServerConfigEffects;
   let store$: MockStore;
   let configurationServiceMock: ConfigurationService;
+  let cookiesServiceMock: CookiesService;
+  let multiSiteServiceMock: MultiSiteService;
 
   beforeEach(() => {
     configurationServiceMock = mock(ConfigurationService);
+    cookiesServiceMock = mock(CookiesService);
+    multiSiteServiceMock = mock(MultiSiteService);
 
     TestBed.configureTestingModule({
       providers: [
         { provide: ConfigurationService, useFactory: () => instance(configurationServiceMock) },
+        { provide: CookiesService, useFactory: () => instance(cookiesServiceMock) },
+        { provide: MultiSiteService, useFactory: () => instance(multiSiteServiceMock) },
         provideMockActions(() => actions$),
         provideMockStore(),
         ServerConfigEffects,
@@ -102,9 +120,11 @@ describe('Server Config Effects', () => {
   describe('loadServerConfig$', () => {
     beforeEach(() => {
       when(configurationServiceMock.getServerConfiguration()).thenReturn(of({}));
+      when(multiSiteServiceMock.getLangUpdatedUrl(anything(), anything())).thenReturn(of('/home;lang=de_DE'));
+      when(multiSiteServiceMock.appendUrlParams(anything(), anything(), anything())).thenReturn('/home;lang=de_DE');
     });
 
-    it('should map to action of type ApplyConfiguration', () => {
+    it('should map to action of type LoadServerConfigSuccess', () => {
       const action = loadServerConfig();
       const completion = loadServerConfigSuccess({ config: {} });
 
@@ -135,5 +155,45 @@ describe('Server Config Effects', () => {
 
       expect(effects.mapToServerConfigError$).toBeObservable(expected$);
     });
+
+    it("should reload the current page if the user's locale cookie differs from the current locale", fakeAsync(() => {
+      when(cookiesServiceMock.get(anything())).thenReturn('de_DE');
+      store$.overrideSelector(getCurrentLocale, 'en_US');
+
+      // mock location.assign() with jest.fn()
+      Object.defineProperty(window, 'location', {
+        value: { assign: jest.fn() },
+        writable: true,
+      });
+
+      const action = loadServerConfigSuccess({ config: {} as ServerConfig });
+      actions$ = of(action);
+
+      effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
+
+      tick(500);
+
+      expect(window.location.assign).toHaveBeenCalled();
+    }));
+
+    it("should not reload the current page if the user's locale cookie is equal to the current locale", fakeAsync(() => {
+      when(cookiesServiceMock.get(anything())).thenReturn('en_US');
+      store$.overrideSelector(getCurrentLocale, 'en_US');
+
+      // mock location.assign() with jest.fn()
+      Object.defineProperty(window, 'location', {
+        value: { assign: jest.fn() },
+        writable: true,
+      });
+
+      const action = loadServerConfigSuccess({ config: {} as ServerConfig });
+      actions$ = of(action);
+
+      effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
+
+      tick(500);
+
+      expect(window.location.assign).not.toHaveBeenCalled();
+    }));
   });
 });
diff --git a/src/app/core/store/core/server-config/server-config.effects.ts b/src/app/core/store/core/server-config/server-config.effects.ts
index b92098d743..41fee9301a 100644
--- a/src/app/core/store/core/server-config/server-config.effects.ts
+++ b/src/app/core/store/core/server-config/server-config.effects.ts
@@ -3,15 +3,17 @@ import { Actions, createEffect, ofType } from '@ngrx/effects';
 import { routerNavigationAction } from '@ngrx/router-store';
 import { Store, select } from '@ngrx/store';
 import { EMPTY, identity } from 'rxjs';
-import { concatMap, first, map, switchMap, takeWhile } from 'rxjs/operators';
+import { concatMap, filter, first, map, switchMap, take, takeWhile, withLatestFrom } from 'rxjs/operators';
 
 import { FeatureToggleService } from 'ish-core/feature-toggle.module';
 import { ServerConfig } from 'ish-core/models/server-config/server-config.model';
 import { ConfigurationService } from 'ish-core/services/configuration/configuration.service';
-import { applyConfiguration } from 'ish-core/store/core/configuration';
+import { applyConfiguration, getCurrentLocale } from 'ish-core/store/core/configuration';
 import { ConfigurationState } from 'ish-core/store/core/configuration/configuration.reducer';
 import { serverConfigError } from 'ish-core/store/core/error';
 import { personalizationStatusDetermined } from 'ish-core/store/customer/user';
+import { CookiesService } from 'ish-core/utils/cookies/cookies.service';
+import { MultiSiteService } from 'ish-core/utils/multi-site/multi-site.service';
 import { delayUntil, mapErrorToAction, mapToPayloadProperty, whenFalsy, whenTruthy } from 'ish-core/utils/operators';
 
 import {
@@ -29,7 +31,9 @@ export class ServerConfigEffects {
     private actions$: Actions,
     private store: Store,
     private configService: ConfigurationService,
-    private featureToggleService: FeatureToggleService
+    private featureToggleService: FeatureToggleService,
+    private cookiesService: CookiesService,
+    private multiSiteService: MultiSiteService
   ) {}
 
   /**
@@ -57,6 +61,34 @@ export class ServerConfigEffects {
     )
   );
 
+  switchToPreferredLanguage$ = createEffect(
+    () =>
+      this.actions$.pipe(
+        ofType(loadServerConfigSuccess),
+        withLatestFrom(this.store.pipe(select(getCurrentLocale))),
+        map(([, currentLocale]) => [this.cookiesService.get('preferredLocale'), currentLocale]),
+        filter(([preferredLocale, locale]) => preferredLocale && preferredLocale !== locale),
+        concatMap(([preferredLocale]) => {
+          const splittedUrl = location.pathname?.split('?');
+          const newUrl = splittedUrl?.[0];
+
+          return this.multiSiteService.getLangUpdatedUrl(preferredLocale, newUrl).pipe(
+            whenTruthy(),
+            take(1),
+            map(modifiedUrl => {
+              const modifiedUrlParams = modifiedUrl === newUrl ? { lang: preferredLocale } : {};
+              return this.multiSiteService.appendUrlParams(modifiedUrl, modifiedUrlParams, splittedUrl?.[1]);
+            }),
+            concatMap(url => {
+              location.assign(url);
+              return EMPTY;
+            })
+          );
+        })
+      ),
+    { dispatch: false }
+  );
+
   loadExtraServerConfig$ = createEffect(() =>
     this.actions$.pipe(
       ofType(loadServerConfig),
diff --git a/src/app/core/utils/multi-site/multi-site.service.spec.ts b/src/app/core/utils/multi-site/multi-site.service.spec.ts
index 09e2ee48a6..1cebde40e9 100644
--- a/src/app/core/utils/multi-site/multi-site.service.spec.ts
+++ b/src/app/core/utils/multi-site/multi-site.service.spec.ts
@@ -1,3 +1,4 @@
+import { APP_BASE_HREF } from '@angular/common';
 import { TestBed } from '@angular/core/testing';
 import { provideMockStore } from '@ngrx/store/testing';
 
@@ -16,7 +17,10 @@ describe('Multi Site Service', () => {
 
   beforeEach(() => {
     TestBed.configureTestingModule({
-      providers: [provideMockStore({ selectors: [{ selector: getMultiSiteLocaleMap, value: multiSiteLocaleMap }] })],
+      providers: [
+        { provide: APP_BASE_HREF, useValue: '/de' },
+        provideMockStore({ selectors: [{ selector: getMultiSiteLocaleMap, value: multiSiteLocaleMap }] }),
+      ],
     });
     multiSiteService = TestBed.inject(MultiSiteService);
   });
@@ -25,21 +29,36 @@ describe('Multi Site Service', () => {
     expect(multiSiteService).toBeTruthy();
   });
   it('should return url unchanged if no language baseHref exists', done => {
-    multiSiteService.getLangUpdatedUrl('de_DE', '/testpath', '/').subscribe(url => {
+    multiSiteService.getLangUpdatedUrl('de_DE', '/testpath').subscribe(url => {
       expect(url).toMatchInlineSnapshot(`"/testpath"`);
       done();
     });
   });
   it('should return with new url if language baseHref exists and language is valid', done => {
-    multiSiteService.getLangUpdatedUrl('en_US', '/de/testpath', '/de').subscribe(url => {
+    multiSiteService.getLangUpdatedUrl('en_US', '/de/testpath').subscribe(url => {
       expect(url).toMatchInlineSnapshot(`"/en/testpath"`);
       done();
     });
   });
   it('should return url unchanged if language baseHref exists but language is invalid', done => {
-    multiSiteService.getLangUpdatedUrl('xy_XY', '/de/testpath', '/de').subscribe(url => {
+    multiSiteService.getLangUpdatedUrl('xy_XY', '/de/testpath').subscribe(url => {
       expect(url).toMatchInlineSnapshot(`"/de/testpath"`);
       done();
     });
   });
+
+  it.each([
+    [undefined, undefined, 'undefined'],
+    ['/test', undefined, '/test'],
+    ['/test', {}, '/test'],
+    ['/test', { foo: 'bar' }, '/test;foo=bar'],
+    ['/test', { foo: 'bar', marco: 'polo' }, '/test;foo=bar;marco=polo'],
+    ['/test?query=q', undefined, '/test?query=q'],
+    ['/test?query=q', {}, '/test?query=q'],
+    ['/test?query=q', { foo: 'bar' }, '/test;foo=bar?query=q'],
+    ['/test?query=q', { foo: 'bar', marco: 'polo' }, '/test;foo=bar;marco=polo?query=q'],
+  ])(`should transform "%s" with %j to "%s"`, (url, params, expected) => {
+    const splittedUrl = url?.split('?');
+    expect(multiSiteService.appendUrlParams(splittedUrl?.[0], params, splittedUrl?.[1])).toBe(expected);
+  });
 });
diff --git a/src/app/core/utils/multi-site/multi-site.service.ts b/src/app/core/utils/multi-site/multi-site.service.ts
index 73fe67177d..1f6ccff7fe 100644
--- a/src/app/core/utils/multi-site/multi-site.service.ts
+++ b/src/app/core/utils/multi-site/multi-site.service.ts
@@ -1,4 +1,5 @@
-import { Injectable } from '@angular/core';
+import { APP_BASE_HREF } from '@angular/common';
+import { Inject, Injectable } from '@angular/core';
 import { Store, select } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { map, take } from 'rxjs/operators';
@@ -9,7 +10,7 @@ export type MultiSiteLocaleMap = Record<string, unknown> | undefined;
 
 @Injectable({ providedIn: 'root' })
 export class MultiSiteService {
-  constructor(private store: Store) {}
+  constructor(private store: Store, @Inject(APP_BASE_HREF) private baseHref: string) {}
 
   /**
    * returns the current url, modified to fit the locale parameter if the environment parameter "multiSiteLocaleMap" is set
@@ -19,7 +20,7 @@ export class MultiSiteService {
    * @param baseHref the current baseHref which needs to be replaced
    * @returns the modified url
    */
-  getLangUpdatedUrl(locale: string, url: string, baseHref: string): Observable<string> {
+  getLangUpdatedUrl(locale: string, url: string): Observable<string> {
     return this.store.pipe(
       select(getMultiSiteLocaleMap),
       take(1),
@@ -33,15 +34,25 @@ export class MultiSiteService {
          */
         if (
           multiSiteLocaleMap &&
-          Object.values(multiSiteLocaleMap).includes(baseHref) &&
+          Object.values(multiSiteLocaleMap).includes(this.baseHref) &&
           localeMapHasLangString(locale, multiSiteLocaleMap)
         ) {
-          newUrl = newUrl.replace(baseHref, multiSiteLocaleMap[locale]);
+          newUrl = newUrl.replace(this.baseHref, multiSiteLocaleMap[locale]);
         }
         return newUrl;
       })
     );
   }
+
+  appendUrlParams(url: string, urlParams: Record<string, string>, queryParams: string | undefined): string {
+    return `${url}${
+      urlParams
+        ? Object.keys(urlParams)
+            .map(k => `;${k}=${urlParams[k]}`)
+            .join('')
+        : ''
+    }${queryParams ? `?${queryParams}` : ''}`;
+  }
 }
 
 function localeMapHasLangString(

From 61bb9f8b1e6a80330b6917650f44350708081e28 Mon Sep 17 00:00:00 2001
From: Silke <s.grueber@intershop.de>
Date: Fri, 1 Sep 2023 11:13:11 +0200
Subject: [PATCH 3/8] fix: switch language only if available

---
 .../server-config.effects.spec.ts             | 23 ++++++++++++++++++-
 .../server-config/server-config.effects.ts    | 21 +++++++++++------
 2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/src/app/core/store/core/server-config/server-config.effects.spec.ts b/src/app/core/store/core/server-config/server-config.effects.spec.ts
index 4cb132a2ee..6992b0e336 100644
--- a/src/app/core/store/core/server-config/server-config.effects.spec.ts
+++ b/src/app/core/store/core/server-config/server-config.effects.spec.ts
@@ -8,7 +8,7 @@ import { anything, instance, mock, when } from 'ts-mockito';
 
 import { ServerConfig } from 'ish-core/models/server-config/server-config.model';
 import { ConfigurationService } from 'ish-core/services/configuration/configuration.service';
-import { getCurrentLocale } from 'ish-core/store/core/configuration/configuration.selectors';
+import { getAvailableLocales, getCurrentLocale } from 'ish-core/store/core/configuration/configuration.selectors';
 import { CoreStoreModule } from 'ish-core/store/core/core-store.module';
 import { serverConfigError } from 'ish-core/store/core/error';
 import { CookiesService } from 'ish-core/utils/cookies/cookies.service';
@@ -122,6 +122,7 @@ describe('Server Config Effects', () => {
       when(configurationServiceMock.getServerConfiguration()).thenReturn(of({}));
       when(multiSiteServiceMock.getLangUpdatedUrl(anything(), anything())).thenReturn(of('/home;lang=de_DE'));
       when(multiSiteServiceMock.appendUrlParams(anything(), anything(), anything())).thenReturn('/home;lang=de_DE');
+      store$.overrideSelector(getAvailableLocales, ['en_US', 'de_DE', 'fr_FR']);
     });
 
     it('should map to action of type LoadServerConfigSuccess', () => {
@@ -195,5 +196,25 @@ describe('Server Config Effects', () => {
 
       expect(window.location.assign).not.toHaveBeenCalled();
     }));
+
+    it("should not reload the current page if the user's cookie locale is not available", fakeAsync(() => {
+      when(cookiesServiceMock.get(anything())).thenReturn('it_IT');
+      store$.overrideSelector(getCurrentLocale, 'en_US');
+
+      // mock location.assign() with jest.fn()
+      Object.defineProperty(window, 'location', {
+        value: { assign: jest.fn() },
+        writable: true,
+      });
+
+      const action = loadServerConfigSuccess({ config: {} as ServerConfig });
+      actions$ = of(action);
+
+      effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
+
+      tick(500);
+
+      expect(window.location.assign).not.toHaveBeenCalled();
+    }));
   });
 });
diff --git a/src/app/core/store/core/server-config/server-config.effects.ts b/src/app/core/store/core/server-config/server-config.effects.ts
index 41fee9301a..fcbcaf9b51 100644
--- a/src/app/core/store/core/server-config/server-config.effects.ts
+++ b/src/app/core/store/core/server-config/server-config.effects.ts
@@ -8,7 +8,7 @@ import { concatMap, filter, first, map, switchMap, take, takeWhile, withLatestFr
 import { FeatureToggleService } from 'ish-core/feature-toggle.module';
 import { ServerConfig } from 'ish-core/models/server-config/server-config.model';
 import { ConfigurationService } from 'ish-core/services/configuration/configuration.service';
-import { applyConfiguration, getCurrentLocale } from 'ish-core/store/core/configuration';
+import { applyConfiguration, getAvailableLocales, getCurrentLocale } from 'ish-core/store/core/configuration';
 import { ConfigurationState } from 'ish-core/store/core/configuration/configuration.reducer';
 import { serverConfigError } from 'ish-core/store/core/error';
 import { personalizationStatusDetermined } from 'ish-core/store/customer/user';
@@ -65,18 +65,25 @@ export class ServerConfigEffects {
     () =>
       this.actions$.pipe(
         ofType(loadServerConfigSuccess),
-        withLatestFrom(this.store.pipe(select(getCurrentLocale))),
-        map(([, currentLocale]) => [this.cookiesService.get('preferredLocale'), currentLocale]),
-        filter(([preferredLocale, locale]) => preferredLocale && preferredLocale !== locale),
-        concatMap(([preferredLocale]) => {
+        withLatestFrom(this.store.pipe(select(getAvailableLocales)), this.store.pipe(select(getCurrentLocale))),
+        map(([, availableLocales, currentLocale]) => ({
+          cookieLocale: this.cookiesService.get('preferredLocale'),
+          availableLocales,
+          currentLocale,
+        })),
+        filter(
+          ({ cookieLocale, availableLocales, currentLocale }) =>
+            cookieLocale && availableLocales?.includes(cookieLocale) && cookieLocale !== currentLocale
+        ),
+        concatMap(({ cookieLocale }) => {
           const splittedUrl = location.pathname?.split('?');
           const newUrl = splittedUrl?.[0];
 
-          return this.multiSiteService.getLangUpdatedUrl(preferredLocale, newUrl).pipe(
+          return this.multiSiteService.getLangUpdatedUrl(cookieLocale, newUrl).pipe(
             whenTruthy(),
             take(1),
             map(modifiedUrl => {
-              const modifiedUrlParams = modifiedUrl === newUrl ? { lang: preferredLocale } : {};
+              const modifiedUrlParams = modifiedUrl === newUrl ? { lang: cookieLocale } : {};
               return this.multiSiteService.appendUrlParams(modifiedUrl, modifiedUrlParams, splittedUrl?.[1]);
             }),
             concatMap(url => {

From a8cf2d8182fbe8bdf982987dd1eec07d9f41b6bc Mon Sep 17 00:00:00 2001
From: Silke <s.grueber@intershop.de>
Date: Fri, 1 Sep 2023 11:20:31 +0200
Subject: [PATCH 4/8] fix: revert fix for language switch in ssr-dev mode

---
 src/app/core/configurations/configuration.meta.ts | 6 +-----
 src/app/core/store/core/core-store.module.ts      | 5 ++++-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/app/core/configurations/configuration.meta.ts b/src/app/core/configurations/configuration.meta.ts
index 02534841fc..3c6ab84544 100644
--- a/src/app/core/configurations/configuration.meta.ts
+++ b/src/app/core/configurations/configuration.meta.ts
@@ -20,9 +20,7 @@ class SimpleParamMap {
 
 // eslint-disable-next-line complexity
 function extractConfigurationParameters(state: ConfigurationState, paramMap: SimpleParamMap) {
-  const keys: (keyof ConfigurationState)[] = PRODUCTION_MODE
-    ? ['lang']
-    : ['channel', 'application', 'lang', 'currency', 'identityProvider'];
+  const keys: (keyof ConfigurationState)[] = ['channel', 'application', 'lang', 'currency', 'identityProvider'];
   const properties: Partial<ConfigurationState> = keys
     .filter(key => paramMap.has(key) && paramMap.get(key) !== 'default')
     .map(key => ({ [key]: paramMap.get(key) }))
@@ -53,14 +51,12 @@ function extractConfigurationParameters(state: ConfigurationState, paramMap: Sim
   if (Object.keys(properties).length) {
     return configurationReducer(state, applyConfiguration(properties));
   }
-
   return state;
 }
 
 /**
  * meta reducer for overriding client side state if supplied by server
  */
-
 export function configurationMeta(reducer: ActionReducer<CoreState>): ActionReducer<CoreState> {
   let first = false;
 
diff --git a/src/app/core/store/core/core-store.module.ts b/src/app/core/store/core/core-store.module.ts
index 12bc7e7f43..830f4786d5 100644
--- a/src/app/core/store/core/core-store.module.ts
+++ b/src/app/core/store/core/core-store.module.ts
@@ -29,7 +29,10 @@ const coreReducers: ActionReducerMap<CoreState> = {
 
 const coreEffects = [ErrorEffects, ViewconfEffects, ConfigurationEffects, MessagesEffects, ServerConfigEffects];
 
-const coreMetaReducers: MetaReducer<CoreState>[] = [ngrxStateTransferMeta, configurationMeta];
+const coreMetaReducers: MetaReducer<CoreState>[] = [
+  ngrxStateTransferMeta,
+  ...(PRODUCTION_MODE ? [] : [configurationMeta]),
+];
 
 @NgModule({
   imports: [

From 1b5a91173b830dbc284a6b323fe2bb3fd79f6bbd Mon Sep 17 00:00:00 2001
From: Silke <s.grueber@intershop.de>
Date: Fri, 1 Sep 2023 13:23:24 +0200
Subject: [PATCH 5/8] feat: add feature toggle 'saveLanguageSelection'

---
 docs/concepts/configuration.md                |  1 +
 docs/guides/migrations.md                     |  3 +
 .../server-config.effects.spec.ts             | 97 +++++++++----------
 .../server-config/server-config.effects.ts    |  1 +
 .../language-switch.component.spec.ts         |  3 +
 .../language-switch.component.ts              | 14 ++-
 src/environments/environment.model.ts         | 17 +++-
 7 files changed, 78 insertions(+), 58 deletions(-)

diff --git a/docs/concepts/configuration.md b/docs/concepts/configuration.md
index a6139451dc..10fbebfb60 100644
--- a/docs/concepts/configuration.md
+++ b/docs/concepts/configuration.md
@@ -159,6 +159,7 @@ Of course, the ICM server must supply appropriate REST resources to leverage fun
 | productNotifications         | Product notifications feature for price and in stock notifications                                                                              |
 | rating                       | Display product ratings                                                                                                                         |
 | recently                     | Display recently viewed products (additional configuration via `dataRetention` configuration options)                                           |
+| saveLanguageSelection        | Save the user's language selection and restore it after pwa load                                                                                |
 | storeLocator                 | Display physical stores and their addresses                                                                                                     |
 | **B2B Features**             |                                                                                                                                                 |
 | businessCustomerRegistration | Create business customers on registration                                                                                                       |
diff --git a/docs/guides/migrations.md b/docs/guides/migrations.md
index ef5bb17637..79edb9a0ca 100644
--- a/docs/guides/migrations.md
+++ b/docs/guides/migrations.md
@@ -18,6 +18,9 @@ Be aware that some browsers no longer accept cookies with `SameSite=None` withou
 Before by default no `SameSite` was set so browsers treated it as `SameSite=Lax`, this needs to be set explicitly now if it is really intended.
 For migrating check the calls of the `cookies.service` `put` method whether they need to be adapted.
 
+The user's language selection is saved as a cookie now and restored after the pwa is loaded.
+This functionality can be enabled/disabled by the feature toggle `saveLanguageSelection`.
+
 ## 4.0 to 4.1
 
 The Intershop PWA now uses Node.js 18.16.0 LTS with the corresponding npm version 9.5.1 to resolve an issue with Azure Docker deployments (see #1416).
diff --git a/src/app/core/store/core/server-config/server-config.effects.spec.ts b/src/app/core/store/core/server-config/server-config.effects.spec.ts
index 6992b0e336..75bf2bbac5 100644
--- a/src/app/core/store/core/server-config/server-config.effects.spec.ts
+++ b/src/app/core/store/core/server-config/server-config.effects.spec.ts
@@ -6,6 +6,7 @@ import { cold, hot } from 'jasmine-marbles';
 import { Observable, noop, of, throwError } from 'rxjs';
 import { anything, instance, mock, when } from 'ts-mockito';
 
+import { FeatureToggleService } from 'ish-core/feature-toggle.module';
 import { ServerConfig } from 'ish-core/models/server-config/server-config.model';
 import { ConfigurationService } from 'ish-core/services/configuration/configuration.service';
 import { getAvailableLocales, getCurrentLocale } from 'ish-core/store/core/configuration/configuration.selectors';
@@ -74,16 +75,19 @@ describe('Server Config Effects', () => {
   let configurationServiceMock: ConfigurationService;
   let cookiesServiceMock: CookiesService;
   let multiSiteServiceMock: MultiSiteService;
+  let featureToggleServiceMock: FeatureToggleService;
 
   beforeEach(() => {
     configurationServiceMock = mock(ConfigurationService);
     cookiesServiceMock = mock(CookiesService);
     multiSiteServiceMock = mock(MultiSiteService);
+    featureToggleServiceMock = mock(FeatureToggleService);
 
     TestBed.configureTestingModule({
       providers: [
         { provide: ConfigurationService, useFactory: () => instance(configurationServiceMock) },
         { provide: CookiesService, useFactory: () => instance(cookiesServiceMock) },
+        { provide: FeatureToggleService, useFactory: () => instance(featureToggleServiceMock) },
         { provide: MultiSiteService, useFactory: () => instance(multiSiteServiceMock) },
         provideMockActions(() => actions$),
         provideMockStore(),
@@ -120,9 +124,6 @@ describe('Server Config Effects', () => {
   describe('loadServerConfig$', () => {
     beforeEach(() => {
       when(configurationServiceMock.getServerConfiguration()).thenReturn(of({}));
-      when(multiSiteServiceMock.getLangUpdatedUrl(anything(), anything())).thenReturn(of('/home;lang=de_DE'));
-      when(multiSiteServiceMock.appendUrlParams(anything(), anything(), anything())).thenReturn('/home;lang=de_DE');
-      store$.overrideSelector(getAvailableLocales, ['en_US', 'de_DE', 'fr_FR']);
     });
 
     it('should map to action of type LoadServerConfigSuccess', () => {
@@ -157,64 +158,62 @@ describe('Server Config Effects', () => {
       expect(effects.mapToServerConfigError$).toBeObservable(expected$);
     });
 
-    it("should reload the current page if the user's locale cookie differs from the current locale", fakeAsync(() => {
-      when(cookiesServiceMock.get(anything())).thenReturn('de_DE');
-      store$.overrideSelector(getCurrentLocale, 'en_US');
-
-      // mock location.assign() with jest.fn()
-      Object.defineProperty(window, 'location', {
-        value: { assign: jest.fn() },
-        writable: true,
-      });
-
+    describe('restore language after loadServerConfigSuccess$', () => {
       const action = loadServerConfigSuccess({ config: {} as ServerConfig });
-      actions$ = of(action);
-
-      effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
-
-      tick(500);
-
-      expect(window.location.assign).toHaveBeenCalled();
-    }));
+      beforeEach(() => {
+        when(multiSiteServiceMock.getLangUpdatedUrl(anything(), anything())).thenReturn(of('/home;lang=de_DE'));
+        when(multiSiteServiceMock.appendUrlParams(anything(), anything(), anything())).thenReturn('/home;lang=de_DE');
+        when(featureToggleServiceMock.enabled(anything())).thenReturn(true);
+        store$.overrideSelector(getAvailableLocales, ['en_US', 'de_DE', 'fr_FR']);
+        store$.overrideSelector(getCurrentLocale, 'en_US');
+
+        // mock location.assign() with jest.fn()
+        Object.defineProperty(window, 'location', {
+          value: { assign: jest.fn() },
+          writable: true,
+        });
+      });
 
-    it("should not reload the current page if the user's locale cookie is equal to the current locale", fakeAsync(() => {
-      when(cookiesServiceMock.get(anything())).thenReturn('en_US');
-      store$.overrideSelector(getCurrentLocale, 'en_US');
+      it("should reload the current page if the user's locale cookie differs from the current locale", fakeAsync(() => {
+        when(cookiesServiceMock.get(anything())).thenReturn('de_DE');
 
-      // mock location.assign() with jest.fn()
-      Object.defineProperty(window, 'location', {
-        value: { assign: jest.fn() },
-        writable: true,
-      });
+        actions$ = of(action);
+        effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
 
-      const action = loadServerConfigSuccess({ config: {} as ServerConfig });
-      actions$ = of(action);
+        tick(500);
+        expect(window.location.assign).toHaveBeenCalled();
+      }));
 
-      effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
+      it("should not reload the current page if the user's locale cookie is equal to the current locale", fakeAsync(() => {
+        when(cookiesServiceMock.get(anything())).thenReturn('en_US');
 
-      tick(500);
+        actions$ = of(action);
+        effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
 
-      expect(window.location.assign).not.toHaveBeenCalled();
-    }));
+        tick(500);
+        expect(window.location.assign).not.toHaveBeenCalled();
+      }));
 
-    it("should not reload the current page if the user's cookie locale is not available", fakeAsync(() => {
-      when(cookiesServiceMock.get(anything())).thenReturn('it_IT');
-      store$.overrideSelector(getCurrentLocale, 'en_US');
+      it('should not reload the current page if the feature toggle `saveLanguageSelection` is off', fakeAsync(() => {
+        when(cookiesServiceMock.get(anything())).thenReturn('de_DE');
+        when(featureToggleServiceMock.enabled(anything())).thenReturn(false);
 
-      // mock location.assign() with jest.fn()
-      Object.defineProperty(window, 'location', {
-        value: { assign: jest.fn() },
-        writable: true,
-      });
+        actions$ = of(action);
+        effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
 
-      const action = loadServerConfigSuccess({ config: {} as ServerConfig });
-      actions$ = of(action);
+        tick(500);
+        expect(window.location.assign).not.toHaveBeenCalled();
+      }));
 
-      effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
+      it("should not reload the current page if the user's cookie locale is not available", fakeAsync(() => {
+        when(cookiesServiceMock.get(anything())).thenReturn('it_IT');
 
-      tick(500);
+        actions$ = of(action);
+        effects.switchToPreferredLanguage$.subscribe({ next: noop, error: fail, complete: noop });
 
-      expect(window.location.assign).not.toHaveBeenCalled();
-    }));
+        tick(500);
+        expect(window.location.assign).not.toHaveBeenCalled();
+      }));
+    });
   });
 });
diff --git a/src/app/core/store/core/server-config/server-config.effects.ts b/src/app/core/store/core/server-config/server-config.effects.ts
index fcbcaf9b51..d3d62976c0 100644
--- a/src/app/core/store/core/server-config/server-config.effects.ts
+++ b/src/app/core/store/core/server-config/server-config.effects.ts
@@ -65,6 +65,7 @@ export class ServerConfigEffects {
     () =>
       this.actions$.pipe(
         ofType(loadServerConfigSuccess),
+        takeWhile(() => this.featureToggleService.enabled('saveLanguageSelection')),
         withLatestFrom(this.store.pipe(select(getAvailableLocales)), this.store.pipe(select(getCurrentLocale))),
         map(([, availableLocales, currentLocale]) => ({
           cookieLocale: this.cookiesService.get('preferredLocale'),
diff --git a/src/app/shell/header/language-switch/language-switch.component.spec.ts b/src/app/shell/header/language-switch/language-switch.component.spec.ts
index 8b29a2de6b..282d066ef1 100644
--- a/src/app/shell/header/language-switch/language-switch.component.spec.ts
+++ b/src/app/shell/header/language-switch/language-switch.component.spec.ts
@@ -8,6 +8,7 @@ import { of } from 'rxjs';
 import { instance, mock, when } from 'ts-mockito';
 
 import { AppFacade } from 'ish-core/facades/app.facade';
+import { FeatureToggleService } from 'ish-core/feature-toggle.module';
 import { MakeHrefPipe } from 'ish-core/pipes/make-href.pipe';
 import { CookiesService } from 'ish-core/utils/cookies/cookies.service';
 
@@ -20,6 +21,7 @@ describe('Language Switch Component', () => {
   let appFacade: AppFacade;
   const locales = ['en_US', 'de_DE', 'fr_FR'];
   const cookiesServiceMock = mock(CookiesService);
+  const featureToggleServiceMock = mock(FeatureToggleService);
 
   beforeEach(async () => {
     appFacade = mock(AppFacade);
@@ -34,6 +36,7 @@ describe('Language Switch Component', () => {
       providers: [
         { provide: AppFacade, useFactory: () => instance(appFacade) },
         { provide: CookiesService, useValue: instance(cookiesServiceMock) },
+        { provide: FeatureToggleService, useValue: instance(featureToggleServiceMock) },
       ],
     }).compileComponents();
   });
diff --git a/src/app/shell/header/language-switch/language-switch.component.ts b/src/app/shell/header/language-switch/language-switch.component.ts
index 12f4362335..96e984980d 100644
--- a/src/app/shell/header/language-switch/language-switch.component.ts
+++ b/src/app/shell/header/language-switch/language-switch.component.ts
@@ -3,6 +3,7 @@ import { ChangeDetectionStrategy, Component, Input, OnInit } from '@angular/core
 import { Observable } from 'rxjs';
 
 import { AppFacade } from 'ish-core/facades/app.facade';
+import { FeatureToggleService } from 'ish-core/feature-toggle.module';
 import { CookiesService } from 'ish-core/utils/cookies/cookies.service';
 
 @Component({
@@ -23,6 +24,7 @@ export class LanguageSwitchComponent implements OnInit {
   constructor(
     private appFacade: AppFacade,
     private cookiesService: CookiesService,
+    private featureToggleService: FeatureToggleService,
     public location: LocationStrategy
   ) {}
 
@@ -32,10 +34,12 @@ export class LanguageSwitchComponent implements OnInit {
   }
 
   setLocaleCookie(locale: string) {
-    this.cookiesService.put('preferredLocale', locale, {
-      expires: new Date(new Date().setFullYear(new Date().getFullYear() + 1)),
-      path: '/',
-    });
-    return true;
+    if (this.featureToggleService.enabled('saveLanguageSelection')) {
+      this.cookiesService.put('preferredLocale', locale, {
+        expires: new Date(new Date().setFullYear(new Date().getFullYear() + 1)),
+        path: '/',
+      });
+      return true;
+    }
   }
 }
diff --git a/src/environments/environment.model.ts b/src/environments/environment.model.ts
index c087fe2699..1cb85fd21b 100644
--- a/src/environments/environment.model.ts
+++ b/src/environments/environment.model.ts
@@ -25,12 +25,13 @@ export interface Environment {
   /* FEATURE TOGGLES */
   features: (
     | 'compare'
+    | 'contactUs'
+    | 'extraConfiguration'
+    | 'productNotifications'
     | 'rating'
     | 'recently'
-    | 'productNotifications'
+    | 'saveLanguageSelection'
     | 'storeLocator'
-    | 'contactUs'
-    | 'extraConfiguration'
     /* B2B features */
     | 'businessCustomerRegistration'
     | 'costCenters'
@@ -149,7 +150,15 @@ export const ENVIRONMENT_DEFAULTS: Omit<Environment, 'icmChannel'> = {
   hybridApplication: '-',
 
   /* FEATURE TOGGLES */
-  features: ['compare', 'contactUs', 'productNotifications', 'rating', 'recently', 'storeLocator'],
+  features: [
+    'compare',
+    'contactUs',
+    'productNotifications',
+    'rating',
+    'recently',
+    'saveLanguageSelection',
+    'storeLocator',
+  ],
 
   /* PROGRESSIVE WEB APP CONFIGURATIONS */
   smallBreakpointWidth: 576,

From ccd6134d5656f4db8ed4d1162447e0dd51c9f88d Mon Sep 17 00:00:00 2001
From: Marcel Eisentraut <meisentraut@intershop.de>
Date: Mon, 4 Sep 2023 16:25:18 +0200
Subject: [PATCH 6/8] refactor: better tests for make-href pipe

---
 src/app/core/pipes/make-href.pipe.spec.ts | 30 ++++++++++++++---------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/src/app/core/pipes/make-href.pipe.spec.ts b/src/app/core/pipes/make-href.pipe.spec.ts
index f9bceebcbd..782c098bbd 100644
--- a/src/app/core/pipes/make-href.pipe.spec.ts
+++ b/src/app/core/pipes/make-href.pipe.spec.ts
@@ -17,6 +17,7 @@ describe('Make Href Pipe', () => {
       providers: [{ provide: MultiSiteService, useFactory: () => instance(multiSiteService) }, MakeHrefPipe],
     });
     makeHrefPipe = TestBed.inject(MakeHrefPipe);
+
     when(multiSiteService.getLangUpdatedUrl(anything(), anything())).thenCall((url: string, _: LocationStrategy) =>
       of(url)
     );
@@ -28,19 +29,17 @@ describe('Make Href Pipe', () => {
   it('should be created', () => {
     expect(makeHrefPipe).toBeTruthy();
   });
-  // workaround for https://github.com/DefinitelyTyped/DefinitelyTyped/issues/34617
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  it.each<any | jest.DoneCallback>([
-    [undefined, undefined, 'undefined'],
-    ['/test', undefined, '/test'],
-  ])(`should transform "%s" with %j to "%s"`, (url, params, expected, done: jest.DoneCallback) => {
-    makeHrefPipe.transform({ path: () => url, getBaseHref: () => '/' } as LocationStrategy, params).subscribe(res => {
-      expect(res).toEqual(expected);
-      done();
-    });
+
+  it('should call appendUrlParams from the multiSiteService if no parameter exists', done => {
+    makeHrefPipe
+      .transform({ path: () => '/de/test', getBaseHref: () => '/de' } as LocationStrategy, undefined)
+      .subscribe(() => {
+        verify(multiSiteService.appendUrlParams(anything(), anything(), anything())).once();
+        done();
+      });
   });
 
-  it('should call the multiSiteService if lang parameter exists', done => {
+  it('should call getLangUpdatedUrl from the multiSiteService if lang parameter exists', done => {
     makeHrefPipe
       .transform({ path: () => '/de/test', getBaseHref: () => '/de' } as LocationStrategy, { lang: 'en_US' })
       .subscribe(() => {
@@ -48,4 +47,13 @@ describe('Make Href Pipe', () => {
         done();
       });
   });
+
+  it('should call appendUrlParams from the multiSiteService if other parameter exists', done => {
+    makeHrefPipe
+      .transform({ path: () => '/de/test', getBaseHref: () => '/de' } as LocationStrategy, { foo: 'bar' })
+      .subscribe(() => {
+        verify(multiSiteService.appendUrlParams(anything(), anything(), anything())).once();
+        done();
+      });
+  });
 });

From f35708603762bb3c4073671696d078703b9ac63a Mon Sep 17 00:00:00 2001
From: Marcel Eisentraut <meisentraut@intershop.de>
Date: Tue, 5 Sep 2023 09:30:14 +0200
Subject: [PATCH 7/8] refactor: improve switchToPreferredLanguage effect

---
 .../server-config/server-config.effects.ts    | 71 ++++++++++---------
 1 file changed, 37 insertions(+), 34 deletions(-)

diff --git a/src/app/core/store/core/server-config/server-config.effects.ts b/src/app/core/store/core/server-config/server-config.effects.ts
index d3d62976c0..99fd14278d 100644
--- a/src/app/core/store/core/server-config/server-config.effects.ts
+++ b/src/app/core/store/core/server-config/server-config.effects.ts
@@ -61,41 +61,44 @@ export class ServerConfigEffects {
     )
   );
 
-  switchToPreferredLanguage$ = createEffect(
-    () =>
-      this.actions$.pipe(
-        ofType(loadServerConfigSuccess),
-        takeWhile(() => this.featureToggleService.enabled('saveLanguageSelection')),
-        withLatestFrom(this.store.pipe(select(getAvailableLocales)), this.store.pipe(select(getCurrentLocale))),
-        map(([, availableLocales, currentLocale]) => ({
-          cookieLocale: this.cookiesService.get('preferredLocale'),
-          availableLocales,
-          currentLocale,
-        })),
-        filter(
-          ({ cookieLocale, availableLocales, currentLocale }) =>
-            cookieLocale && availableLocales?.includes(cookieLocale) && cookieLocale !== currentLocale
-        ),
-        concatMap(({ cookieLocale }) => {
-          const splittedUrl = location.pathname?.split('?');
-          const newUrl = splittedUrl?.[0];
+  switchToPreferredLanguage$ =
+    !SSR &&
+    createEffect(
+      () =>
+        this.actions$.pipe(
+          ofType(loadServerConfigSuccess),
+          take(1),
+          takeWhile(() => this.featureToggleService.enabled('saveLanguageSelection')),
+          withLatestFrom(this.store.pipe(select(getAvailableLocales)), this.store.pipe(select(getCurrentLocale))),
+          map(([, availableLocales, currentLocale]) => ({
+            cookieLocale: this.cookiesService.get('preferredLocale'),
+            availableLocales,
+            currentLocale,
+          })),
+          filter(
+            ({ cookieLocale, availableLocales, currentLocale }) =>
+              cookieLocale && availableLocales?.includes(cookieLocale) && cookieLocale !== currentLocale
+          ),
+          concatMap(({ cookieLocale }) => {
+            const splittedUrl = location.pathname?.split('?');
+            const newUrl = splittedUrl?.[0];
 
-          return this.multiSiteService.getLangUpdatedUrl(cookieLocale, newUrl).pipe(
-            whenTruthy(),
-            take(1),
-            map(modifiedUrl => {
-              const modifiedUrlParams = modifiedUrl === newUrl ? { lang: cookieLocale } : {};
-              return this.multiSiteService.appendUrlParams(modifiedUrl, modifiedUrlParams, splittedUrl?.[1]);
-            }),
-            concatMap(url => {
-              location.assign(url);
-              return EMPTY;
-            })
-          );
-        })
-      ),
-    { dispatch: false }
-  );
+            return this.multiSiteService.getLangUpdatedUrl(cookieLocale, newUrl).pipe(
+              whenTruthy(),
+              take(1),
+              map(modifiedUrl => {
+                const modifiedUrlParams = modifiedUrl === newUrl ? { lang: cookieLocale } : {};
+                return this.multiSiteService.appendUrlParams(modifiedUrl, modifiedUrlParams, splittedUrl?.[1]);
+              }),
+              concatMap(url => {
+                location.assign(url);
+                return EMPTY;
+              })
+            );
+          })
+        ),
+      { dispatch: false }
+    );
 
   loadExtraServerConfig$ = createEffect(() =>
     this.actions$.pipe(

From 754cb24db4dc6e815c34b255355ef3b60811e953 Mon Sep 17 00:00:00 2001
From: Stefan Hauke <s.hauke@intershop.de>
Date: Fri, 8 Sep 2023 12:40:01 +0200
Subject: [PATCH 8/8] chore: small documentation improvements

---
 docs/concepts/configuration.md | 2 +-
 docs/guides/migrations.md      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/docs/concepts/configuration.md b/docs/concepts/configuration.md
index 10fbebfb60..b7a109ac99 100644
--- a/docs/concepts/configuration.md
+++ b/docs/concepts/configuration.md
@@ -159,7 +159,7 @@ Of course, the ICM server must supply appropriate REST resources to leverage fun
 | productNotifications         | Product notifications feature for price and in stock notifications                                                                              |
 | rating                       | Display product ratings                                                                                                                         |
 | recently                     | Display recently viewed products (additional configuration via `dataRetention` configuration options)                                           |
-| saveLanguageSelection        | Save the user's language selection and restore it after pwa load                                                                                |
+| saveLanguageSelection        | Save the user's language selection and restore it after PWA load                                                                                |
 | storeLocator                 | Display physical stores and their addresses                                                                                                     |
 | **B2B Features**             |                                                                                                                                                 |
 | businessCustomerRegistration | Create business customers on registration                                                                                                       |
diff --git a/docs/guides/migrations.md b/docs/guides/migrations.md
index 79edb9a0ca..4a3854f624 100644
--- a/docs/guides/migrations.md
+++ b/docs/guides/migrations.md
@@ -18,8 +18,8 @@ Be aware that some browsers no longer accept cookies with `SameSite=None` withou
 Before by default no `SameSite` was set so browsers treated it as `SameSite=Lax`, this needs to be set explicitly now if it is really intended.
 For migrating check the calls of the `cookies.service` `put` method whether they need to be adapted.
 
-The user's language selection is saved as a cookie now and restored after the pwa is loaded.
-This functionality can be enabled/disabled by the feature toggle `saveLanguageSelection`.
+The user's language selection is saved as a cookie (`preferredLocale`) now and restored after the PWA is loaded.
+This functionality can be enabled/disabled with the feature toggle `saveLanguageSelection`.
 
 ## 4.0 to 4.1