improvement(files): correct two comments that described the wrong behavior

The resolution loop's comment claimed at most one rendered document is resident.
It is not: every resolved buffer is held until the archive is assembled, bounded
by the request's remaining budget. The loop resolves one at a time, it does not
release one at a time.

RENDERED_DOCUMENT_HEADROOM_BYTES was documented as bounding the expansion beyond
the declared size, but it is passed straight through as maxBytes and is an
absolute ceiling on the rendered document — renamed to MAX_RENDERED_DOCUMENT_BYTES
so the name matches. Download failures also carry a fallback message, so a
transport error surfaces something better than a bare "Failed to fetch".

Author: waleedlatif1

apps/sim/app/api/workspaces/[id]/files/download/route.ts

@@ -27,7 +27,7 @@ import { downloadFileStream } from '@/lib/uploads/core/storage-service'
 import {
   formatFileSize,
   isRenderableDocumentName,
-  RENDERED_DOCUMENT_HEADROOM_BYTES,
+  MAX_RENDERED_DOCUMENT_BYTES,
 } from '@/lib/uploads/utils/file-utils'
 import { docNotReadyMessage, isDocNotReadyError } from '@/lib/uploads/utils/servable-file-response'
 import { buildZipEntryPaths } from '@/lib/uploads/zip-entry-path'
@@ -153,10 +153,10 @@ export const GET = withRouteHandler(
         return selectionTooLargeResponse(declaredBytes)
       }
 
-      // Generated documents are resolved before the archive starts. They are the only
-      // entries whose bytes decide anything, and every status this route returns comes
-      // from them — once the first byte is written the status code is committed. They
-      // resolve one at a time so at most one rendered document is resident.
+      // Generated documents are resolved before the archive starts: once the first byte
+      // is written the status code is committed, so anything that can still fail the
+      // request has to fail here. Their buffers are held until the archive is assembled,
+      // bounded by what is left of the request's byte budget.
       const renderedDocuments = new Map<string, Buffer>()
       const pendingNames: string[] = []
       let renderedBytes = 0
@@ -165,9 +165,9 @@ export const GET = withRouteHandler(
         if (!needsRendering(file)) continue
 
         const remaining = MAX_ZIP_DOWNLOAD_BYTES - renderedBytes
-        // A source renders to something larger than it declared, so the allowance is the
-        // render headroom — bounded by what is left of the request's budget.
-        const allowance = Math.min(remaining, RENDERED_DOCUMENT_HEADROOM_BYTES)
+        // A source's declared size says nothing about what it renders to, so the cap is
+        // the per-document ceiling, bounded by what is left of the budget.
+        const allowance = Math.min(remaining, MAX_RENDERED_DOCUMENT_BYTES)
 
         try {
           const { buffer } = await fetchServableWorkspaceFileBuffer(file, { maxBytes: allowance })
@@ -177,10 +177,10 @@ export const GET = withRouteHandler(
           if (error instanceof PayloadSizeLimitError) {
             // Blamed on the entry when its own ceiling was the binding cap; otherwise the
             // documents ahead of it have consumed the budget.
-            return allowance === RENDERED_DOCUMENT_HEADROOM_BYTES
+            return allowance === MAX_RENDERED_DOCUMENT_BYTES
               ? NextResponse.json(
                   {
-                    error: `"${file.name}" renders to more than ${formatFileSize(RENDERED_DOCUMENT_HEADROOM_BYTES)} and is too large to include in a zip; download it on its own instead.`,
+                    error: `"${file.name}" renders to more than ${formatFileSize(MAX_RENDERED_DOCUMENT_BYTES)} and is too large to include in a zip; download it on its own instead.`,
                   },
                   { status: 400 }
                 )

apps/sim/app/workspace/[workspaceId]/files/files.tsx

@@ -951,7 +951,7 @@ export function Files() {
         })
       } catch (err) {
         logger.error('Failed to download file:', err)
-        toast.error(toError(err).message)
+        toast.error(getErrorMessage(err, `Failed to download "${file.name}"`))
       }
     },
     [workspaceId]
@@ -1078,7 +1078,7 @@ export function Files() {
         await triggerArchiveDownload({ workspaceId, ...selection })
       } catch (err) {
         logger.error('Failed to download selection:', err)
-        toast.error(toError(err).message)
+        toast.error(getErrorMessage(err, 'Failed to download the selected files'))
       }
     },
     [workspaceId]

apps/sim/lib/core/utils/node-stream.ts

@@ -1,4 +1,4 @@
-import type { Readable } from 'stream'
+import type { Readable } from 'node:stream'
 
 /**
  * Bridges a Node `Readable` into a WHATWG `ReadableStream` suitable for a `Response`

apps/sim/lib/uploads/client/download.ts

@@ -2,7 +2,6 @@ import { requestRaw } from '@/lib/api/client/request'
 import { downloadWorkspaceFileItemsContract } from '@/lib/api/contracts/workspace-file-folders'
 import type { WorkspaceFileRecord } from '@/lib/uploads/contexts/workspace'
 
-/** Hand a fetched blob to the browser as a file save, then release the object URL. */
 export function saveBlob(blob: Blob, fileName: string): void {
   const objectUrl = URL.createObjectURL(blob)
   const anchor = document.createElement('a')

apps/sim/lib/uploads/utils/file-utils.ts

@@ -218,11 +218,11 @@ export function getFileExtension(filename: string): string {
 const RENDERABLE_DOCUMENT_EXTENSIONS = new Set(['pdf', 'docx', 'pptx', 'xlsx'])
 
 /**
- * How far a generated document may render beyond the source it declared. A generator
- * source is text and is orders of magnitude smaller than the document it produces, so
- * this bounds the expansion rather than the document.
+ * Ceiling on a single rendered generated document. A generator source is text and is
+ * orders of magnitude smaller than the document it produces, so the declared size is no
+ * bound at all and the rendered bytes need a cap of their own.
  */
-export const RENDERED_DOCUMENT_HEADROOM_BYTES = 50 * 1024 * 1024
+export const MAX_RENDERED_DOCUMENT_BYTES = 50 * 1024 * 1024
 
 /** True when `fileName` may be backed by a generation source rather than final bytes. */
 export function isRenderableDocumentName(fileName: string): boolean {