fix: improve legacy-to-MMDS replacement mapping and dashboard fallback

__tests__/component-mapper.test.js

@@ -0,0 +1,101 @@
+const {
+  mapComponent,
+  isMmdsPackage,
+  formatReplacementDisplay,
+  getReplacementOptions,
+  buildLegacyReplacementEntry,
+  extractGuidanceSnippet,
+} = require('../scripts/lib/component-mapper');
+
+const MMDS = {
+  react: ['Button', 'TextButton', 'Icon', 'Skeleton'],
+  reactNative: [
+    'AvatarAccount',
+    'AvatarFavicon',
+    'AvatarIcon',
+    'AvatarNetwork',
+    'AvatarToken',
+    'Button',
+    'Skeleton',
+    'TextButton',
+    'Text',
+  ],
+};
+
+describe('component-mapper', () => {
+  test('maps mobile Skeleton from components-temp hint to MMDS Skeleton', () => {
+    const result = mapComponent(
+      {
+        name: 'Skeleton',
+        project: 'mobile',
+        deprecationMessage:
+          '@deprecated Please update your code to use `Skeleton` from `app/component-library/components-temp/Skeleton`.',
+      },
+      MMDS,
+    );
+
+    expect(result).toMatchObject({
+      component: 'Skeleton',
+      package: '@metamask/design-system-react-native',
+    });
+  });
+
+  test('maps mobile Avatar to multiple avatar components', () => {
+    const result = mapComponent(
+      {
+        name: 'Avatar',
+        project: 'mobile',
+        deprecationMessage:
+          '@deprecated Please update your code to use the individual avatar components from `@metamask/design-system-react-native` such as `AvatarAccount`, `AvatarFavicon`, `AvatarIcon`, `AvatarNetwork`, or `AvatarToken`.',
+      },
+      MMDS,
+    );
+
+    expect(result.component).toBe('AvatarAccount');
+    expect(result.package).toBe('@metamask/design-system-react-native');
+    expect(getReplacementOptions(result)).toEqual([
+      'AvatarAccount',
+      'AvatarFavicon',
+      'AvatarIcon',
+      'AvatarNetwork',
+      'AvatarToken',
+    ]);
+  });
+
+  test('maps mobile ButtonLink to TextButton and Button', () => {
+    const result = mapComponent(
+      {
+        name: 'ButtonLink',
+        project: 'mobile',
+        deprecationMessage:
+          '@deprecated ButtonLink has been replaced by design-system components. Use `TextButton` for inline links. Use `Button` with `variant={ButtonVariant.Tertiary}` for standalone link-style buttons.',
+      },
+      MMDS,
+    );
+
+    expect(formatReplacementDisplay(result)).toBe('TextButton · Button');
+  });
+
+  test('buildLegacyReplacementEntry uses guidance when no MMDS mapping exists', () => {
+    const entry = buildLegacyReplacementEntry(null, '@deprecated Legacy component with no mapped target yet.');
+
+    expect(entry.replacement).toBeNull();
+    expect(entry.replacementOptions).toEqual([]);
+    expect(entry.guidance).toContain('Legacy component with no mapped target yet');
+  });
+
+  test('isMmdsPackage identifies design-system packages', () => {
+    expect(isMmdsPackage('@metamask/design-system-react-native')).toBe(true);
+    expect(isMmdsPackage('component-library')).toBe(false);
+  });
+
+  test('extractGuidanceSnippet trims long deprecation prose', () => {
+    const snippet = extractGuidanceSnippet(
+      '* @deprecated Please update your code to use `Accordion` from `@metamask/design-system-react-native`. The API may have changed — compare props before migrating. @see README',
+      40,
+    );
+
+    expect(snippet.endsWith('…')).toBe(true);
+    expect(snippet.length).toBeLessThanOrEqual(40);
+  });
+});