Backport: Export parseJsonEventStream and uiMessageChunkSchema from "ai" package (#8852)

This is an automated backport of #8849 to the v5.0 branch.

Co-authored-by: Nathan Rajlich <[email protected]>

Author: vercel-ai-sdk[bot]

.changeset/gentle-students-begin.md

@@ -0,0 +1,5 @@
+---
+'ai': patch
+---
+
+Export `parseJsonEventStream` and `uiMessageChunkSchema` from "ai" package

packages/ai/src/index.ts

@@ -6,6 +6,7 @@ export {
   dynamicTool,
   generateId,
   jsonSchema,
+  parseJsonEventStream,
   tool,
   zodSchema,
   type IdGenerator,

packages/ai/src/ui-message-stream/index.ts

@@ -3,7 +3,11 @@ export { createUIMessageStreamResponse } from './create-ui-message-stream-respon
 export { JsonToSseTransformStream } from './json-to-sse-transform-stream';
 export { pipeUIMessageStreamToResponse } from './pipe-ui-message-stream-to-response';
 export { readUIMessageStream } from './read-ui-message-stream';
-export type { InferUIMessageChunk, UIMessageChunk } from './ui-message-chunks';
+export {
+  uiMessageChunkSchema,
+  type InferUIMessageChunk,
+  type UIMessageChunk,
+} from './ui-message-chunks';
 export { UI_MESSAGE_STREAM_HEADERS } from './ui-message-stream-headers';
 export type { UIMessageStreamOnFinishCallback } from './ui-message-stream-on-finish-callback';
 export type { UIMessageStreamWriter } from './ui-message-stream-writer';