fix(input-format): require file key, keep mixed/partial values in JSON mode

Addresses review round 2 (Greptile P1 + Cursor):
- parseInputFormatFiles now requires a non-empty key (the uploader always sets
  one); an external/signed URL with no recoverable key no longer opens uploader
  mode or reaches workflowInput.files only to be rejected.
- defaultFileFieldMode uses the uploader only when EVERY entry is run-ready;
  a mixed array with any legacy/partial entry stays in JSON mode so the uploader
  can't drop the entries it can't represent on the next save.

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/starter/input-format-files.test.ts

@@ -105,4 +105,8 @@ describe('defaultFileFieldMode', () => {
     expect(defaultFileFieldMode('[{"data":"<base64>","name":"x.pdf"}]')).toBe('json')
     expect(defaultFileFieldMode('{"csv":"a,b,c"}')).toBe('json')
   })
+
+  it.concurrent('uses json when only some entries are run-ready (no silent drop)', () => {
+    expect(defaultFileFieldMode(JSON.stringify([file, { name: 'legacy-only' }]))).toBe('json')
+  })
 })

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/starter/input-format-files.ts

@@ -67,5 +67,9 @@ export function defaultFileFieldMode(value: string | undefined): 'upload' | 'jso
     return 'json'
   }
   if (!Array.isArray(parsed)) return 'json'
-  return parsed.length === 0 || parseInputFormatFiles(parsed).length > 0 ? 'upload' : 'json'
+  if (parsed.length === 0) return 'upload'
+  // Only use the uploader when EVERY entry is run-ready; if any entry is legacy
+  // or partial, stay in JSON mode so the uploader can't drop the entries it
+  // cannot represent when the field is next saved.
+  return parseInputFormatFiles(parsed).length === parsed.length ? 'upload' : 'json'
 }

apps/sim/lib/workflows/input-format.test.ts

@@ -299,6 +299,12 @@ describe('parseInputFormatFiles', () => {
       )
     ).toEqual([])
   })
+
+  it.concurrent('rejects files without a usable key', () => {
+    const { key, ...noKey } = file
+    expect(parseInputFormatFiles(JSON.stringify([noKey]))).toEqual([])
+    expect(parseInputFormatFiles(JSON.stringify([{ ...file, key: '' }]))).toEqual([])
+  })
 })
 
 describe('collectInputFormatFiles', () => {

apps/sim/lib/workflows/input-format.ts

@@ -85,12 +85,16 @@ export function parseInputFormatFiles(value: unknown): InputFormatFile[] {
     if (file === null || typeof file !== 'object') return false
     const f = file as InputFormatFile
     // Require the full run-ready shape the executor's normalizeStartFile needs,
-    // so a partial object never opens in uploader mode or reaches the files
-    // channel only to be rejected (which would silently drop every file).
+    // including a usable `key` (the uploader always sets one), so a partial
+    // object or an external/signed URL never opens in uploader mode or reaches
+    // the files channel only to be rejected — which would silently drop every
+    // file. Anything short of this falls back to the JSON editor.
     return (
       typeof f.id === 'string' &&
       typeof f.name === 'string' &&
       typeof f.url === 'string' &&
+      typeof f.key === 'string' &&
+      f.key.length > 0 &&
       typeof f.size === 'number' &&
       Number.isFinite(f.size) &&
       typeof f.type === 'string'