Fix desktop file link downloads

apps/desktop/src/components/assistant-ui/markdown-file-links.test.tsx

@@ -0,0 +1,37 @@
+import { cleanup, fireEvent, render, screen } from '@testing-library/react'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+
+import { $connection } from '@/store/session'
+
+import { MarkdownTextContent } from './markdown-text'
+
+const desktopWindow = window as unknown as { hermesDesktop?: Window['hermesDesktop'] }
+const initialHermesDesktop = desktopWindow.hermesDesktop
+
+afterEach(() => {
+  cleanup()
+  $connection.set(null)
+  vi.restoreAllMocks()
+
+  if (initialHermesDesktop) {
+    desktopWindow.hermesDesktop = initialHermesDesktop
+  } else {
+    delete desktopWindow.hermesDesktop
+  }
+})
+
+describe('MarkdownTextContent file links', () => {
+  it('opens file links through the remote download endpoint', () => {
+    const openExternal = vi.fn().mockResolvedValue(undefined)
+    desktopWindow.hermesDesktop = { openExternal } as unknown as Window['hermesDesktop']
+    $connection.set({ baseUrl: 'https://gw', mode: 'remote', token: 's e/cret' } as never)
+
+    render(<MarkdownTextContent isRunning={false} text="[Report](file:///tmp/a%20b.pdf)" />)
+
+    fireEvent.click(screen.getByRole('link', { name: 'Open a b.pdf' }))
+
+    expect(openExternal).toHaveBeenCalledWith(
+      'https://gw/api/files/download?path=%2Ftmp%2Fa%20b.pdf&token=s%20e%2Fcret'
+    )
+  })
+})

apps/desktop/src/components/assistant-ui/markdown-text.tsx

@@ -213,6 +213,21 @@ function MediaAttachment({ path }: { path: string }) {
     )
   }
 
+  if (kind === 'file') {
+    return (
+      <a
+        className="font-semibold text-foreground underline underline-offset-4 decoration-current/20 wrap-anywhere"
+        href="#"
+        onClick={event => {
+          event.preventDefault()
+          openExternalLink(mediaExternalUrl(path))
+        }}
+      >
+        Open {name}
+      </a>
+    )
+  }
+
   return (
     <a
       className="font-semibold text-foreground underline underline-offset-4 decoration-current/20 wrap-anywhere"

apps/desktop/src/lib/markdown-preprocess.ts

@@ -16,6 +16,7 @@ const INLINE_CODE_SPLIT_RE = /(`[^`\n]+`)/g
 // and keeps the emphasis run intact. Other trailing punctuation is still peeled
 // off by the final `[^\s<>"'`*.,;:!?]` class.
 const RAW_URL_RE = /https?:\/\/[^\s<>"'`*]+[^\s<>"'`*.,;:!?]/g
+const LOCAL_FILE_LINK_RE = /(?<!!)\[([^\]\n]+)\]\((file:\/\/[^)\s]+|\/[^)\s]+)\)/g
 const LOCAL_PREVIEW_URL_RE = /(^|\s)https?:\/\/(?:localhost|127\.0\.0\.1|0\.0\.0\.0|\[::1\])(?::\d+)?\/?[^\s<>"'`]*/gi
 const LOCAL_PREVIEW_ONLY_RE = /^https?:\/\/(?:localhost|127\.0\.0\.1|0\.0\.0\.0|\[::1\])(?::\d+)?\/?$/i
 const URL_ONLY_LINE_RE = /^\s*https?:\/\/\S+\s*$/i
@@ -138,14 +139,53 @@ function autoLinkRawUrls(text: string): string {
   })
 }
 
+function filePathFromHref(href: string): string {
+  if (/^file:/i.test(href)) {
+    try {
+      return decodeURIComponent(new URL(href).pathname)
+    } catch {
+      return href.replace(/^file:\/\//i, '')
+    }
+  }
+
+  try {
+    return decodeURIComponent(href)
+  } catch {
+    return href
+  }
+}
+
+function isAbsoluteFileHref(href: string): boolean {
+  if (/^file:/i.test(href)) {
+    return true
+  }
+
+  const clean = href.split(/[?#]/, 1)[0] || ''
+  const name = clean.split('/').filter(Boolean).pop() || ''
+
+  return /^\.[A-Za-z0-9]{1,12}$/.test(name.slice(name.lastIndexOf('.')))
+}
+
+function rewriteLocalFileLinks(text: string): string {
+  return text.replace(LOCAL_FILE_LINK_RE, (match: string, label: string, href: string) => {
+    if (!isAbsoluteFileHref(href)) {
+      return match
+    }
+
+    return `[${label}](#media:${encodeURIComponent(filePathFromHref(href))})`
+  })
+}
+
 function normalizeVisibleProse(text: string): string {
   return text
     .split(INLINE_CODE_SPLIT_RE)
     .map(part =>
       part.startsWith('`')
         ? part
         : autoLinkRawUrls(
-            part.replace(/`{3,}/g, '').replace(LOCAL_PREVIEW_URL_RE, '$1').replace(CITATION_MARKER_RE, '')
+            rewriteLocalFileLinks(
+              part.replace(/`{3,}/g, '').replace(LOCAL_PREVIEW_URL_RE, '$1').replace(CITATION_MARKER_RE, '')
+            )
           )
     )
     .join('')