fix(tui): preserve streamed text during tool call transitions

AI Assistant · steipete · commit d6cbaea434d8 · 2026-02-26T19:50:06.000Z
Fixes #27674 The TUI was erasing already-streamed assistant text when tool calls were triggered. This happened because the finalize() method in TuiStreamAssembler was not using the protectBoundaryDrops option when updating run state. Now finalize() applies the same boundary drop protection as ingestDelta(), ensuring that streamed text before tool calls is preserved when the final payload drops earlier content blocks.
diff --git a/src/tui/tui-stream-assembler.ts b/src/tui/tui-stream-assembler.ts
@@ -151,7 +151,7 @@ export class TuiStreamAssembler {
     const streamedDisplayText = state.displayText;
     const streamedTextBlocks = [...state.contentBlocks];
     const streamedSawNonTextContentBlocks = state.sawNonTextContentBlocks;
-    this.updateRunState(state, message, showThinking);
+    this.updateRunState(state, message, showThinking, { protectBoundaryDrops: true });
     const finalComposed = state.displayText;
     const shouldKeepStreamedText =
       streamedSawNonTextContentBlocks &&
