Give video extensions the same pre-text, prompt, and post-text fields as the main form.

Co-authored-by: Cursor <cursoragent@cursor.com>

utils/promptParts.ts

@@ -36,6 +36,46 @@ export function restorePromptParts(saved: string, stored?: Partial<PromptParts>
   }
 }
 
+export type PromptWrapperFields = {
+  promptPre?: string
+  promptPost?: string
+}
+
+function hasWrapperKey(item: object | null | undefined, key: 'promptPre' | 'promptPost') {
+  return Boolean(item && Object.prototype.hasOwnProperty.call(item, key))
+}
+
+/** First source that actually sent the key wins, including empty string. Omitted keys fall through. */
+export function resolvePromptWrappers(
+  ...sources: Array<PromptWrapperFields | null | undefined>
+) {
+  let promptPre = ''
+  let promptPost = ''
+  let sawPre = false
+  let sawPost = false
+  for (const source of sources) {
+    if (!source) continue
+    if (!sawPre && hasWrapperKey(source, 'promptPre') && source.promptPre != null) {
+      promptPre = sanitizePromptPart(source.promptPre)
+      sawPre = true
+    }
+    if (!sawPost && hasWrapperKey(source, 'promptPost') && source.promptPost != null) {
+      promptPost = sanitizePromptPart(source.promptPost)
+      sawPost = true
+    }
+    if (sawPre && sawPost) break
+  }
+  return { promptPre, promptPost }
+}
+
+export function persistPromptWrappers(item?: PromptWrapperFields | null): PromptWrapperFields {
+  if (!item) return {}
+  const next: PromptWrapperFields = {}
+  if (hasWrapperKey(item, 'promptPre') && item.promptPre != null) next.promptPre = sanitizePromptPart(item.promptPre)
+  if (hasWrapperKey(item, 'promptPost') && item.promptPost != null) next.promptPost = sanitizePromptPart(item.promptPost)
+  return next
+}
+
 export function formatPromptParts(
   stored?: { prompt?: string; promptPre?: string; promptPost?: string } | null,
   midOverride?: string