fix(markdown): handle unavailable reply quote links

src/lib/utils/__tests__/quote-link-utils.test.ts

@@ -0,0 +1,45 @@
+import { describe, expect, it } from 'vitest';
+import { formatQuoteNumber, isUnavailableQuoteTarget, shouldShowFloatingQuotePreview } from '../quote-link-utils';
+
+describe('quote-link-utils', () => {
+  it('formats quote numbers with the expected prefix', () => {
+    expect(formatQuoteNumber(123)).toBe('>>123');
+    expect(formatQuoteNumber()).toBe('>>?');
+  });
+
+  it('marks deleted and removed comments as unavailable quote targets', () => {
+    expect(isUnavailableQuoteTarget(undefined)).toBe(false);
+    expect(isUnavailableQuoteTarget({ deleted: true, removed: false })).toBe(true);
+    expect(isUnavailableQuoteTarget({ deleted: false, removed: true })).toBe(true);
+    expect(isUnavailableQuoteTarget({ deleted: false, removed: false })).toBe(false);
+  });
+
+  it('only shows floating previews for available targets that are hovered out of view', () => {
+    expect(
+      shouldShowFloatingQuotePreview({
+        hoveredCid: 'cid-1',
+        outOfViewCid: 'cid-1',
+        quoteCid: 'cid-1',
+        isUnavailable: false,
+      }),
+    ).toBe(true);
+
+    expect(
+      shouldShowFloatingQuotePreview({
+        hoveredCid: 'cid-1',
+        outOfViewCid: 'cid-1',
+        quoteCid: 'cid-1',
+        isUnavailable: true,
+      }),
+    ).toBe(false);
+
+    expect(
+      shouldShowFloatingQuotePreview({
+        hoveredCid: 'cid-1',
+        outOfViewCid: 'cid-2',
+        quoteCid: 'cid-1',
+        isUnavailable: false,
+      }),
+    ).toBe(false);
+  });
+});

src/lib/utils/quote-link-utils.ts

@@ -0,0 +1,17 @@
+import type { Comment } from '@bitsocialhq/bitsocial-react-hooks';
+
+export const formatQuoteNumber = (number?: number) => `>>${number ?? '?'}`;
+
+export const isUnavailableQuoteTarget = (comment?: Partial<Pick<Comment, 'deleted' | 'removed'>> | null) => Boolean(comment?.deleted || comment?.removed);
+
+export const shouldShowFloatingQuotePreview = ({
+  hoveredCid,
+  outOfViewCid,
+  quoteCid,
+  isUnavailable,
+}: {
+  hoveredCid: string | null;
+  outOfViewCid: string | null;
+  quoteCid?: string;
+  isUnavailable?: boolean;
+}) => Boolean(quoteCid && !isUnavailable && hoveredCid === quoteCid && outOfViewCid === quoteCid);