agentHost: restore history using user turn boundaries#323284
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Skip non-renderable assistant events during session replay so they do not terminate the current turn and split restored responses. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Pull request overview
This PR fixes Copilot session history replay so that empty/non-renderable assistant.message SDK events do not create unintended turn boundaries during reconstruction, preventing restored transcripts from splitting a single interaction into multiple chat responses.
Changes:
- Skip
assistant.messageevents that have no content, no reasoning text, and no tool requests duringmapSessionEventshistory replay. - Add a regression test covering an empty assistant event occurring between model rounds, ensuring subsequent markdown/tool output stays in the same reconstructed turn.
Show a summary per file
| File | Description |
|---|---|
| src/vs/platform/agentHost/node/copilot/mapSessionEvents.ts | Ignores non-renderable empty assistant messages to avoid prematurely finalizing a parent turn during history replay. |
| src/vs/platform/agentHost/test/node/mapSessionEvents.test.ts | Adds regression coverage to ensure empty assistant events don’t split one interaction into multiple restored turns. |
Review details
- Files reviewed: 2/2 changed files
- Comments generated: 0
- Review effort level: Low
Use real top-level user messages as restored chat turn boundaries so multiple model rounds remain one response. Preserve completion and cancellation state for terminal empty messages, task completion, aborts, and subagent activity. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
roblourens
changed the title
vijayupadya
approved these changes
Jun 28, 2026
vijayupadya
approved these changes
Jun 28, 2026
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Summary
Testing
npm run typecheck-client./scripts/test.sh --run src/vs/platform/agentHost/test/node/mapSessionEvents.test.tsnpm run valid-layers-checknpm run precommitFixes #323283.
(Written by Copilot)