fix(md): file streaming patch preview

apps/sim/app/workspace/[workspaceId]/home/components/mothership-view/components/resource-content/resource-content.tsx

@@ -32,6 +32,7 @@ import {
   RESOURCE_TAB_ICON_BUTTON_CLASS,
   RESOURCE_TAB_ICON_CLASS,
 } from '@/app/workspace/[workspaceId]/home/components/mothership-view/components/resource-tabs/resource-tab-controls'
+import { hasRenderableFilePreviewContent } from '@/app/workspace/[workspaceId]/home/hooks/use-file-preview-sessions'
 import type {
   GenericResourceData,
   MothershipResource,
@@ -116,13 +117,19 @@ export const ResourceContent = memo(function ResourceContent({
   const disableStreamingAutoScroll = previewSession?.operation === 'patch'
   const rawPreviewText = previewSession?.previewText
   const streamingPreviewText =
-    typeof rawPreviewText === 'string' && rawPreviewText.length > 0 ? rawPreviewText : undefined
+    previewSession &&
+    typeof rawPreviewText === 'string' &&
+    hasRenderableFilePreviewContent(previewSession)
+      ? rawPreviewText
+      : undefined
   const pendingOrStreamingFilePreviewText =
-    previewSession?.fileId === resource.id && typeof rawPreviewText === 'string'
+    previewSession?.fileId === resource.id &&
+    typeof rawPreviewText === 'string' &&
+    hasRenderableFilePreviewContent(previewSession)
       ? rawPreviewText
       : undefined
 
-  if (previewSession && resource.id === 'streaming-file') {
+  if (resource.id === 'streaming-file') {
     return (
       <div className='flex h-full flex-col overflow-hidden'>
         {streamingPreviewText !== undefined ? (

apps/sim/app/workspace/[workspaceId]/home/components/mothership-view/mothership-view.tsx

@@ -6,6 +6,7 @@ import { cn } from '@/lib/core/utils/cn'
 import { getFileExtension } from '@/lib/uploads/utils/file-utils'
 import type { PreviewMode } from '@/app/workspace/[workspaceId]/files/components/file-viewer'
 import { RICH_PREVIEWABLE_EXTENSIONS } from '@/app/workspace/[workspaceId]/files/components/file-viewer'
+import { hasRenderableFilePreviewContent } from '@/app/workspace/[workspaceId]/home/hooks/use-file-preview-sessions'
 import type {
   GenericResourceData,
   MothershipResource,
@@ -23,7 +24,7 @@ const PREVIEW_CYCLE: Record<PreviewMode, PreviewMode> = {
 /**
  * Whether the active resource should show the in-progress file stream.
  * The synthetic `streaming-file` tab always shows it; a real file tab only shows it
- * when the streamed fileId matches that exact resource.
+ * after a preview content event has arrived for that exact resource.
  */
 function shouldShowStreamingFilePanel(
   previewSession: FilePreviewSession | null | undefined,
@@ -32,7 +33,9 @@ function shouldShowStreamingFilePanel(
   if (!previewSession || previewSession.status === 'complete' || !active) return false
   if (active.id === 'streaming-file') return true
   if (active.type !== 'file') return false
-  if (active.id && previewSession.fileId === active.id) return true
+  if (active.id && previewSession.fileId === active.id) {
+    return hasRenderableFilePreviewContent(previewSession)
+  }
   return false
 }