fix(post form): block temporary media links

src/components/post-form/__tests__/post-form.test.tsx

@@ -52,7 +52,7 @@ const testState = vi.hoisted(() => ({
 
 vi.mock('react-i18next', () => ({
   useTranslation: () => ({
-    t: (key: string) => key,
+    t: (key: string, options?: Record<string, unknown>) => (options?.domain ? `${key}:${options.domain}` : key),
   }),
 }));
 
@@ -401,8 +401,14 @@ describe('PostForm', () => {
     expect(globalThis.alert).toHaveBeenCalledWith('invalid_url_alert');
 
     (globalThis.alert as ReturnType<typeof vi.fn>).mockClear();
-    await dispatchInput(linkInput as HTMLInputElement, '');
     await dispatchInput(textarea as HTMLTextAreaElement, 'A valid body');
+    await dispatchInput(linkInput as HTMLInputElement, 'https://i.4cdn.org/gif/file.jpg');
+    await clickByText(table as HTMLTableElement, 'post');
+    expect(globalThis.alert).not.toHaveBeenCalled();
+    expect(container.textContent).toContain('error: expiring_media_link_alert:i.4cdn.org');
+    expect(testState.publishPostMock).not.toHaveBeenCalled();
+
+    await dispatchInput(linkInput as HTMLInputElement, '');
     await clickByText(table as HTMLTableElement, 'post');
     expect(globalThis.alert).toHaveBeenCalledWith('no_board_selected_warning');
 

src/components/post-form/post-form.module.css

@@ -188,6 +188,11 @@
   color: red;
 }
 
+.formError {
+  margin: 8px 0;
+  padding: 6px 5px;
+}
+
 .status {
   padding: 5px;
 }

src/components/post-form/post-form.tsx

@@ -6,6 +6,7 @@ import { Comment, setAccount, useAccount, useEditedComment } from '@bitsocial/bi
 import getShortAddress from '../../lib/get-short-address';
 import useCommunitiesPagesStore from '@bitsocial/bitsocial-react-hooks/dist/stores/communities-pages';
 import { getDisplayMediaInfoType, getLinkMediaInfo } from '../../lib/utils/media-utils';
+import { getExpiringMediaLinkAlert } from '../../lib/utils/media-link-validation-utils';
 import { getPublishURLFilename, isValidPublishURL, isValidURL } from '../../lib/utils/url-utils';
 import { isAllView, isCatalogView, isModQueueView, isModView, isPostPageView, isSubscriptionsView } from '../../lib/utils/view-utils';
 import { useAccountCommunityAddresses } from '../../hooks/use-account-community-addresses';
@@ -346,6 +347,7 @@ const PostFormTable = ({ closeForm, postCid }: { closeForm: () => void; postCid:
   const accountCommunityAddresses = useAccountCommunityAddresses();
 
   const [lengthError, setLengthError] = useState<string | null>(null);
+  const [formError, setFormError] = useState<string | null>(null);
 
   const checkContentLength = useRef(
     debounce((content: string, t: TFunction) => {
@@ -377,6 +379,7 @@ const PostFormTable = ({ closeForm, postCid }: { closeForm: () => void; postCid:
 
     checkContentLength.cancel();
     setLengthError(null);
+    setFormError(null);
 
     if (!currentTitle && !currentContent && !currentUrl) {
       alert(t('empty_comment_alert'));
@@ -386,6 +389,11 @@ const PostFormTable = ({ closeForm, postCid }: { closeForm: () => void; postCid:
       alert(t('invalid_url_alert'));
       return;
     }
+    const expiringMediaLinkAlert = currentUrl ? getExpiringMediaLinkAlert(currentUrl, t) : null;
+    if (expiringMediaLinkAlert) {
+      setFormError(expiringMediaLinkAlert);
+      return;
+    }
 
     if (currentContent.length > 2000) {
       alert(t('error') + ': ' + t('field_too_long'));
@@ -432,6 +440,7 @@ const PostFormTable = ({ closeForm, postCid }: { closeForm: () => void; postCid:
 
     checkContentLength.cancel();
     setLengthError(null);
+    setFormError(null);
 
     if (!currentContent && !currentUrl) {
       alert(t('empty_comment_alert'));
@@ -442,6 +451,11 @@ const PostFormTable = ({ closeForm, postCid }: { closeForm: () => void; postCid:
       alert(t('invalid_url_alert'));
       return;
     }
+    const expiringMediaLinkAlert = currentUrl ? getExpiringMediaLinkAlert(currentUrl, t) : null;
+    if (expiringMediaLinkAlert) {
+      setFormError(expiringMediaLinkAlert);
+      return;
+    }
 
     if (currentContent.length > 2000) {
       alert(t('error') + ': ' + t('field_too_long'));
@@ -527,8 +541,9 @@ const PostFormTable = ({ closeForm, postCid }: { closeForm: () => void; postCid:
           />
         </tbody>
       </table>
-      {publishPostError && <div className={styles.error}>{publishPostError}</div>}
-      {publishReplyError && <div className={styles.error}>{publishReplyError}</div>}
+      {formError && <div className={`${styles.error} ${styles.formError}`}>{formError}</div>}
+      {publishPostError && <div className={`${styles.error} ${styles.formError}`}>{publishPostError}</div>}
+      {publishReplyError && <div className={`${styles.error} ${styles.formError}`}>{publishReplyError}</div>}
       {publishReplyStateMessage && <div className={styles.status}>{publishReplyStateMessage}</div>}
     </>
   );

src/components/reply-modal/__tests__/reply-modal.test.tsx

@@ -414,6 +414,12 @@ describe('ReplyModal', () => {
     expect(container.textContent).toContain('error: invalid_url_alert');
     expect(testState.setPublishReplyOptionsMock).toHaveBeenCalledWith({ spoiler: true });
 
+    await dispatchInput(linkInput, 'https://temp.sh/example.png');
+    await clickButtonByText('post');
+
+    expect(container.textContent).toContain('error: expiring_media_link_alert:{"domain":"temp.sh"}');
+    expect(testState.publishReplyMock).not.toHaveBeenCalled();
+
     await dispatchInput(linkInput, 'https://example.com/file.png');
     await clickButtonByText('post');
 

src/components/reply-modal/reply-modal.tsx

@@ -3,6 +3,7 @@ import { useLocation, useParams } from 'react-router-dom';
 import { useTranslation } from 'react-i18next';
 import type { TFunction } from 'i18next';
 import { setAccount, useAccount } from '@bitsocial/bitsocial-react-hooks';
+import { getExpiringMediaLinkAlert } from '../../lib/utils/media-link-validation-utils';
 import { getPublishURLFilename, isValidPublishURL } from '../../lib/utils/url-utils';
 import { isAllView, isModView, isSubscriptionsView } from '../../lib/utils/view-utils';
 import useSelectedTextStore from '../../stores/use-selected-text-store';
@@ -103,6 +104,11 @@ const ReplyModal = ({ closeModal, showReplyModal, parentCid, parentNumber, threa
       setError(t('error') + ': ' + t('invalid_url_alert'));
       return;
     }
+    const expiringMediaLinkAlert = currentUrl ? getExpiringMediaLinkAlert(currentUrl, t) : null;
+    if (expiringMediaLinkAlert) {
+      setError(expiringMediaLinkAlert);
+      return;
+    }
 
     checkContentLengthRef.current.cancel();
     setLengthError(null);

src/lib/utils/__tests__/url-utils.test.ts

@@ -10,6 +10,7 @@ vi.mock('../clipboard-utils', () => ({
 
 import {
   copyShareLinkToClipboard,
+  getExpiringMediaLinkHostname,
   getHostname,
   getPublishURLFilename,
   is5chanLink,
@@ -62,6 +63,15 @@ describe('url-utils', () => {
     expect(getPublishURLFilename('not-a-url')).toBeNull();
   });
 
+  it('detects publish media hosts with temporary links', () => {
+    expect(getExpiringMediaLinkHostname('https://i.4cdn.org/gif/1712345678900.jpg')).toBe('i.4cdn.org');
+    expect(getExpiringMediaLinkHostname('http://litterbox.catbox.moe/u/example.png')).toBe('litterbox.catbox.moe');
+    expect(getExpiringMediaLinkHostname('https://www.tmpfiles.org/dl/123/file.mp4')).toBe('tmpfiles.org');
+    expect(getExpiringMediaLinkHostname('https://cdn.file.kiwi/example')).toBe('file.kiwi');
+    expect(getExpiringMediaLinkHostname('https://example.com/file.png')).toBeNull();
+    expect(getExpiringMediaLinkHostname('not-a-url')).toBeNull();
+  });
+
   it('copies share links for threads and catalog pages using the production fallback base url', async () => {
     await copyShareLinkToClipboard('music.eth', 'thread', 'cid-123');
     expect(testState.copyToClipboardMock).toHaveBeenCalledWith('https://5chan.app/#/music.eth/thread/cid-123');

src/lib/utils/media-link-validation-utils.ts

@@ -0,0 +1,8 @@
+import { getExpiringMediaLinkHostname } from './url-utils';
+
+type TranslateFn = (key: string, options?: Record<string, unknown>) => string;
+
+export const getExpiringMediaLinkAlert = (url: string, t: TranslateFn): string | null => {
+  const expiringMediaLinkHostname = getExpiringMediaLinkHostname(url);
+  return expiringMediaLinkHostname ? `${t('error')}: ${t('expiring_media_link_alert', { domain: expiringMediaLinkHostname })}` : null;
+};

src/lib/utils/url-utils.ts

@@ -67,6 +67,41 @@ export const normalizePublishURL = (url: string) => {
   return trimmedUrl;
 };
 
+const EXPIRING_MEDIA_LINK_HOSTNAMES = [
+  // 4chan CDN media disappears when threads are pruned, usually after a few hours or days.
+  'i.4cdn.org',
+  // Litterbox temporary uploads can expire after 1 hour, 12 hours, 1 day, or 3 days.
+  'litterbox.catbox.moe',
+  // tmpfiles.org uploads expire after 60 minutes, 6 hours, 12 hours, or 24 hours.
+  'tmpfiles.org',
+  // Filebin uploads are deleted automatically after about 6 days.
+  'filebin.net',
+  // temp.sh files expire after 3 days.
+  'temp.sh',
+  // Termbin pastes are automatically deleted after 1 week.
+  'termbin.com',
+  // Uguu files expire after 3 hours.
+  'uguu.se',
+  // file.kiwi encrypted files are deleted after about 4 days by default.
+  'file.kiwi',
+] as const;
+
+const normalizeHostnameForMatching = (hostname: string) => hostname.toLowerCase().replace(/^www\./, '');
+
+export const getExpiringMediaLinkHostname = (url: string): string | null => {
+  try {
+    const parsedUrl = new URL(normalizePublishURL(url));
+    if (parsedUrl.protocol !== 'https:') {
+      return null;
+    }
+
+    const hostname = normalizeHostnameForMatching(parsedUrl.hostname);
+    return EXPIRING_MEDIA_LINK_HOSTNAMES.find((expiringHostname) => hostname === expiringHostname || hostname.endsWith(`.${expiringHostname}`)) || null;
+  } catch {
+    return null;
+  }
+};
+
 export const isValidPublishURL = (url: string) => {
   try {
     return new URL(normalizePublishURL(url)).protocol === 'https:';