Add font config and asset loading tests (#274)

Adds harness tests for two previously untested areas:

**Font config** (6 tests): loadFont by system name, loadFont by URL,
systemFallback, setFallbackFonts with default/weight-specific fonts,
clearFallbackFonts, error on invalid font name.

**Asset loading** (4 tests): referencedAssets with font type, image URL
type, multiple asset types, and undefined assets.

Covers HybridRiveFontConfig.swift (was 0%), AssetLoader.swift (was 1%),
DataSourceResolver.swift (was 0%), HTTPDataLoader.swift (was 43%).

Author: mfazekas

example/__tests__/asset-loading.harness.ts

@@ -0,0 +1,57 @@
+import { describe, it, expect } from 'react-native-harness';
+import { RiveFileFactory } from '@rive-app/react-native';
+
+const OUT_OF_BAND = require('../assets/rive/out_of_band.riv');
+
+function isExperimental() {
+  return RiveFileFactory.getBackend() === 'experimental';
+}
+
+describe('Asset loading with referencedAssets', () => {
+  // referencedAssets with raw ResolvedReferencedAsset objects only works
+  // on the experimental backend; legacy uses a different resolution path.
+  it('loads file with font asset (type: font)', async () => {
+    if (!isExperimental()) return;
+    const file = await RiveFileFactory.fromSource(OUT_OF_BAND, {
+      'Inter-594377': {
+        sourceAssetId: 'Inter-594377.ttf',
+        type: 'font',
+      },
+    });
+    expect(file).toBeDefined();
+    expect(file.artboardNames.length).toBeGreaterThan(0);
+  });
+
+  it('loads file with image asset via URL (type: image)', async () => {
+    if (!isExperimental()) return;
+    const file = await RiveFileFactory.fromSource(OUT_OF_BAND, {
+      'referenced-image-2929282': {
+        sourceUrl: 'https://picsum.photos/id/237/200/200',
+        type: 'image',
+      },
+    });
+    expect(file).toBeDefined();
+    expect(file.artboardNames.length).toBeGreaterThan(0);
+  });
+
+  it('loads file with multiple asset types', async () => {
+    if (!isExperimental()) return;
+    const file = await RiveFileFactory.fromSource(OUT_OF_BAND, {
+      'Inter-594377': {
+        sourceAssetId: 'Inter-594377.ttf',
+        type: 'font',
+      },
+      'referenced-image-2929282': {
+        sourceUrl: 'https://picsum.photos/id/237/200/200',
+        type: 'image',
+      },
+    });
+    expect(file).toBeDefined();
+  });
+
+  it('loads file without referencedAssets (undefined)', async () => {
+    const file = await RiveFileFactory.fromSource(OUT_OF_BAND, undefined);
+    expect(file).toBeDefined();
+    expect(file.artboardNames.length).toBeGreaterThan(0);
+  });
+});

example/__tests__/font-config.harness.ts

@@ -0,0 +1,60 @@
+import { describe, it, expect } from 'react-native-harness';
+import { Platform } from 'react-native';
+import { RiveFonts } from '@rive-app/react-native';
+
+const SYSTEM_FONT = Platform.OS === 'ios' ? 'Helvetica' : 'sans-serif';
+
+describe('RiveFonts', () => {
+  it('systemFallback() returns a font object', () => {
+    const font = RiveFonts.systemFallback();
+    expect(font).toBeDefined();
+  });
+
+  it('loadFont with system font name', async () => {
+    const font = await RiveFonts.loadFont({ name: SYSTEM_FONT });
+    expect(font).toBeDefined();
+  });
+
+  it('loadFont with URL', async () => {
+    const font = await RiveFonts.loadFont({
+      uri: 'https://raw.githubusercontent.com/google/fonts/main/ofl/kanit/Kanit-Regular.ttf',
+    });
+    expect(font).toBeDefined();
+  });
+
+  it('setFallbackFonts + clearFallbackFonts round-trip', async () => {
+    const systemFont = RiveFonts.systemFallback();
+    const urlFont = await RiveFonts.loadFont({
+      uri: 'https://raw.githubusercontent.com/google/fonts/main/ofl/kanit/Kanit-Regular.ttf',
+    });
+
+    await RiveFonts.setFallbackFonts({
+      default: [urlFont, systemFont],
+    });
+
+    await RiveFonts.clearFallbackFonts();
+  });
+
+  it('setFallbackFonts with weight-specific fonts', async () => {
+    const regular = await RiveFonts.loadFont({
+      uri: 'https://raw.githubusercontent.com/google/fonts/main/ofl/kanit/Kanit-Regular.ttf',
+    });
+    const bold = await RiveFonts.loadFont({
+      uri: 'https://raw.githubusercontent.com/google/fonts/main/ofl/kanit/Kanit-Bold.ttf',
+    });
+    const systemFont = RiveFonts.systemFallback();
+
+    await RiveFonts.setFallbackFonts({
+      default: [regular, systemFont],
+      700: [bold, systemFont],
+    });
+
+    await RiveFonts.clearFallbackFonts();
+  });
+
+  it('loadFont with invalid name throws', async () => {
+    await expect(
+      RiveFonts.loadFont({ name: 'NonExistentFont_XYZ_12345' })
+    ).rejects.toBeDefined();
+  });
+});