Function transform

packages/runtime/src/model-factory.ts:288–303

(chunk, controller)

          const stream = result.stream.pipeThrough(
            new TransformStream({
              transform(chunk, controller) {
                if (chunk.type === 'tool-call') {
                  pendingToolCalls.push(chunk);
                  return;
                }
                if (chunk.type === 'finish') {
                  const details = reasoningDetailsFromMetadata(chunk.providerMetadata);
                  for (const toolCall of pendingToolCalls) {
                    controller.enqueue(
                      details ? withReasoningDetails([toolCall], details)[0] : toolCall,
                    );
                  }
                  pendingToolCalls = [];
                }
                controller.enqueue(chunk);
              },
              flush(controller) {
                for (const toolCall of pendingToolCalls) controller.enqueue(toolCall);
              },