chore: establish learning module baseline

OpenMAIC/tests/hooks/use-slide-background-style.test.ts

@@ -0,0 +1,65 @@
+import { createElement } from 'react';
+import { renderToStaticMarkup } from 'react-dom/server';
+import type { SlideBackground } from '@openmaic/dsl';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+const mocks = vi.hoisted(() => ({
+  resolution: { kind: 'placeholder' } as { kind: 'placeholder' } | { kind: 'url'; url: string },
+}));
+
+vi.mock('@/lib/contexts/media-stage-context', () => ({
+  useMediaStageId: () => 'stage-background',
+}));
+
+vi.mock('@/lib/store/media-generation', () => ({
+  useMediaGenerationStore: (selector: (state: { tasks: Record<string, never> }) => unknown) =>
+    selector({ tasks: {} }),
+}));
+
+vi.mock('@/lib/store/settings', () => ({
+  useSettingsStore: (selector: (state: { imageGenerationEnabled: boolean }) => unknown) =>
+    selector({ imageGenerationEnabled: true }),
+}));
+
+vi.mock('@/lib/media/resolve-media-ref', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@/lib/media/resolve-media-ref')>();
+  return {
+    ...actual,
+    useResolvedMediaRef: () => mocks.resolution,
+  };
+});
+
+import { useSlideBackgroundStyle } from '@/lib/hooks/use-slide-background-style';
+
+const allocatedRef = 'ast_background_allocation';
+const background: SlideBackground = {
+  type: 'image',
+  image: { src: allocatedRef, size: 'cover' },
+};
+
+describe('useSlideBackgroundStyle', () => {
+  function Probe() {
+    return createElement('div', { style: useSlideBackgroundStyle(background).backgroundStyle });
+  }
+
+  beforeEach(() => {
+    mocks.resolution = { kind: 'placeholder' };
+  });
+
+  it('uses the resolved allocation and never the opaque ref in CSS', () => {
+    mocks.resolution = { kind: 'url', url: 'blob:resolved-background' };
+
+    const markup = renderToStaticMarkup(createElement(Probe));
+
+    expect(markup).toContain('background-image:url(blob:resolved-background)');
+    expect(markup).not.toContain(allocatedRef);
+  });
+
+  it('does not emit CSS url() while an allocation is unresolved', () => {
+    const markup = renderToStaticMarkup(createElement(Probe));
+
+    expect(markup).toContain('background-color:#fff');
+    expect(markup).not.toContain('url(');
+    expect(markup).not.toContain(allocatedRef);
+  });
+});