show url copied message in snackbar instead of alert

src/app/app.component.html

@@ -50,3 +50,7 @@
 </header>
 
 <amaze-maze [maze]="maze" (move)="handleMove($event)" />
+
+<div class="snack-bar" [class.visible]="snackBarText()">
+  {{ snackBarText() }}
+</div>

src/app/app.component.scss

@@ -22,3 +22,17 @@ header {
     display: flex;
   }
 }
+
+.snack-bar {
+  background: rgba(255, 255, 255, 0.2);
+  border-radius: 0.5rem;
+  bottom: 2rem;
+  opacity: 0;
+  padding: 1rem;
+  position: absolute;
+  transition: opacity 0.25s;
+
+  &.visible {
+    opacity: 1;
+  }
+}

src/app/app.component.spec.ts

@@ -21,6 +21,15 @@ describe('AppComponent', () => {
     ).and.returnValue(true);
   };
 
+  beforeAll(() => {
+    jasmine.DEFAULT_TIMEOUT_INTERVAL = 10_000;
+    jasmine.clock().install();
+  });
+
+  afterAll(() => {
+    jasmine.clock().uninstall();
+  });
+
   beforeEach(async () => {
     const maze = new Maze(4, new Chooser(42));
     gameStateService = jasmine.createSpyObj<GameStateService>(
@@ -190,5 +199,38 @@ describe('AppComponent', () => {
         'http://example.com/?seed=321',
       );
     });
+
+    it('should show a snack bar confirming that the URL was copied', (done) => {
+      fixture.debugElement
+        .query(By.css('[data-test-id="share-maze-button"]'))
+        .nativeElement.click();
+      fixture.detectChanges();
+
+      expect(
+        fixture.nativeElement.querySelector('.snack-bar').textContent.trim(),
+      ).toBe('URL copied to clipboard');
+      expect(
+        fixture.nativeElement
+          .querySelector('.snack-bar')
+          .classList.contains('visible'),
+      ).toBeTrue();
+
+      // check that the snackbar is hidden after 2s and emptied after 3s
+
+      jasmine.clock().tick(2000);
+      fixture.detectChanges();
+      expect(
+        fixture.nativeElement.querySelector('.snack-bar').style.opacity,
+      ).toBe('0');
+
+      jasmine.clock().tick(1000);
+      fixture.detectChanges();
+      expect(
+        fixture.nativeElement
+          .querySelector('.snack-bar')
+          .classList.contains('visible'),
+      ).toBeFalse();
+      done();
+    });
   });
 });

src/app/app.component.ts

@@ -4,6 +4,8 @@ import {
   inject,
   InjectionToken,
   OnInit,
+  signal,
+  ElementRef,
 } from '@angular/core';
 
 import { MazeComponent } from './maze/maze.component';
@@ -29,13 +31,17 @@ export const WINDOW_TOKEN = new InjectionToken('window', {
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class AppComponent implements OnInit {
+  private readonly elementRef = inject(ElementRef);
   private readonly gameStateService = inject(GameStateService);
 
   private readonly window = inject(WINDOW_TOKEN);
 
   /** The size of the maze, defined as the number of rows/columns in the maze. */
   size = 20;
 
+  /** Text to show in the snack bar. */
+  readonly snackBarText = signal<string | undefined>(undefined);
+
   ngOnInit(): void {
     // Set dark mode if user's OS is using it.
     if (
@@ -94,12 +100,24 @@ export class AppComponent implements OnInit {
   shareMaze(): void {
     const url = this.gameStateService.getShareUrl();
     navigator.clipboard.writeText(url);
-    alert('URL copied to clipboard'); // TODO: snackbar?
+    this.snackBarText.set('URL copied to clipboard');
+    setTimeout(() => this.closeSnackBar(), 2000);
   }
 
   /** Handles a move by the user. */
   handleMove(dir: Dir): void {
     if (this.gameStateService.inAnimation) return;
     this.gameStateService.move(dir);
   }
+
+  private closeSnackBar(): void {
+    // Set the opacity to 0 so the snack bar fades away before removing its text.
+    this.elementRef.nativeElement.querySelector('.snack-bar').style.opacity =
+      '0';
+    setTimeout(() => {
+      this.snackBarText.set(undefined);
+      this.elementRef.nativeElement.querySelector('.snack-bar').style.opacity =
+        '';
+    }, 1000);
+  }
 }

src/app/game-state.service.spec.ts

@@ -14,6 +14,10 @@ describe('GameStateService', () => {
     clock.install();
   });
 
+  afterAll(() => {
+    clock.uninstall();
+  });
+
   beforeEach(() => {
     TestBed.configureTestingModule({});
     service = TestBed.inject(GameStateService);

src/styles.scss

@@ -1,4 +1,4 @@
-@import url('https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,[email protected],100..700,0..1,-50..200');
+@import url('https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,[email protected],100..700,0..1,-50..200&family=Open+Sans:ital,wght@0,300..800;1,300..800');
 
 * {
   margin: 0;
@@ -20,6 +20,7 @@ body {
 
   background: var(--background-color);
   color: var(--text-color);
+  font-family: 'Open Sans', Arial, Helvetica, sans-serif;
 
   &.dark-mode {
     --background-color: #060606;