fix(file): answer null for a key a file input cannot be classified by

fileInputToUserFile normalizes caller-supplied file objects and returns
null for anything it cannot use — but it classified the storage key with
the throwing form, so a key without a recognized context prefix escaped as
a 500 from every operation that normalizes a file input, not just write.

Adds tryInferContextFromKey beside inferContextFromKey, sharing the one
prefix list so a new context cannot be added to half of them. The throwing
form stays right where an unclassifiable key means the platform built one
wrong; the nullable form is for keys that arrived in a request, where an
unrecognized prefix only means this is not a file we can use.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: icecrasher321

apps/sim/lib/internal/file/operations.ts

@@ -44,7 +44,7 @@ import {
 import {
   getFileExtension,
   getMimeTypeFromExtension,
-  inferContextFromKey,
+  tryInferContextFromKey,
 } from '@/lib/uploads/utils/file-utils'
 import {
   downloadFileFromStorage,
@@ -159,6 +159,12 @@ const fileInputToUserFile = (fileInput: unknown) => {
 
   if (!fileUrl && !key) return null
 
+  // A key this normalizer cannot classify is request input we cannot use, which
+  // is what `null` already means here — the throwing form would turn a malformed
+  // client value into a 500 from every operation that normalizes a file input.
+  const context = key ? tryInferContextFromKey(key) : null
+  if (key && !context) return null
+
   return {
     id: key || fileUrl,
     name:
@@ -170,7 +176,9 @@ const fileInputToUserFile = (fileInput: unknown) => {
         ? record.type.trim()
         : 'application/octet-stream',
     key,
-    context: inferContextFromKey(key),
+    // Only absent when there is no key at all — an unclassifiable one returned
+    // above rather than reaching here.
+    context: context ?? undefined,
   }
 }
 

apps/sim/lib/uploads/utils/context-prefix.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from 'vitest'
+import { inferContextFromKey, tryInferContextFromKey } from '@/lib/uploads/utils/file-utils'
+
+describe('tryInferContextFromKey', () => {
+  it('classifies a known prefix the same way the throwing form does', () => {
+    for (const key of ['workspace/a/b.txt', 'execution/a/b/c/d.bin', 'kb/x', 'logs/y']) {
+      expect(tryInferContextFromKey(key)).toBe(inferContextFromKey(key))
+    }
+  })
+
+  it('answers null where the throwing form raises, so caller input cannot 500', () => {
+    for (const key of ['', 'garbage', 'not-a-prefix/x.txt', '../escape']) {
+      expect(tryInferContextFromKey(key)).toBeNull()
+      expect(() => inferContextFromKey(key)).toThrow()
+    }
+  })
+})

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

@@ -757,9 +757,30 @@ export function isInternalFileUrl(fileUrl: string): boolean {
  * row — see `resolveStoredFileContext` — never this prefix.
  */
 export function inferContextFromKey(key: string): StorageContext {
-  if (!key) {
-    throw new Error('Cannot infer context from empty key')
+  const context = tryInferContextFromKey(key)
+  if (!context) {
+    throw new Error(
+      key
+        ? `File key must start with a context prefix (kb/, knowledge-base/, chat/, copilot/, execution/, workspace/, profile-pictures/, og-images/, workspace-logos/, or logs/). Got: ${key}`
+        : 'Cannot infer context from empty key'
+    )
   }
+  return context
+}
+
+/**
+ * {@link inferContextFromKey} for a key that came from a caller rather than from
+ * our own storage, answering `null` instead of throwing.
+ *
+ * The throwing form is right where an unclassifiable key means the platform
+ * built one wrong — that is a bug and should be loud. It is wrong where the key
+ * is request input being normalized, because there an unrecognized prefix just
+ * means "this is not a file we can use", and a throw turns a malformed request
+ * into a 500. Both share this one list so a new context cannot be added to only
+ * half of them.
+ */
+export function tryInferContextFromKey(key: string): StorageContext | null {
+  if (!key) return null
 
   if (key.startsWith('kb/') || key.startsWith('knowledge-base/')) return 'knowledge-base'
   if (key.startsWith('chat/')) return 'chat'
@@ -771,9 +792,7 @@ export function inferContextFromKey(key: string): StorageContext {
   if (key.startsWith('workspace-logos/')) return 'workspace-logos'
   if (key.startsWith('logs/')) return 'logs'
 
-  throw new Error(
-    `File key must start with a context prefix (kb/, knowledge-base/, chat/, copilot/, execution/, workspace/, profile-pictures/, og-images/, workspace-logos/, or logs/). Got: ${key}`
-  )
+  return null
 }
 
 /**