3b03c4b9eb
## Thinking Path > - Paperclip lets operators manage agent work through tasks. > - Task chat keeps responses and run history together. > - A live update rendered every historical bubble and hidden tool row again. > - New image callbacks also forced unchanged markdown to parse again. > - Long conversations saturated the browser main thread. > - This change reuses unchanged history and mounts folded tools on first inspection. > - Operators can read and reply while work continues. ## Linked Issues or Issue Description **What happened?** Chat-style tasks with substantial scrollback became almost unusable. A deterministic browser reproduction with 200 long responses and 4,000 tools consumed 97.8% of the main thread during live updates. It delivered only 8 updates during the sample. **Expected behavior** The task should remain responsive during streaming. Historical markdown and unopened run details should not repeat expensive render work. **Steps to reproduce** 1. Install dependencies with `pnpm install`. 2. Run `pnpm exec playwright test --config tests/perf/task-chat/playwright.config.ts`. 3. Compare the attached performance JSON. The new test fails against the original rendering code. **Paperclip version or commit** Reproduced at `a05b828bc`. The branch is rebased on current master. **Deployment mode** Local Chromium and Vite with deterministic fixtures. No database or agent credentials are required. Related work: #10463 reduces the issue-page bundle. This change addresses repeated rendering after the page loads. No duplicate scrollback fix was found. ## What Changed - Keep the bubble image callback stable so unchanged markdown can skip parsing. - Memoize the settled history separately from the header and streaming tail. Keep the brief renderer and default attachment array stable. - Mount folded tool history on first expansion. Keep it mounted afterward to preserve child state and closing motion. Runtime request receipts remain visible. - Add deterministic rendering tests to the normal Vitest suite and an opt-in Chromium regression fixture. - Document the reproduction, commands, scope, and local measurements. ## Verification - Browser reproduction: 97.8% main-thread utilization before; 11.6% after for tail-only updates; 31.5% after when projection recreates history objects. Both fixed cases delivered 32 updates. - Browser checks pass for scroll-position retention, typing, return to latest, tool inspection, and retained expansion state. - Focused component suite: 155 tests passed. Post-rebase thread/performance rerun: 101 tests passed. - Recursive typecheck, build, Storybook build, and token gates passed. UI typecheck passed after the final edits. - Local UI/CLI lane: 5,910 tests passed; ten files hit worker-start timeouts, then all ten passed with two workers (20 tests). Shared/adapter lane: 3,128 tests passed. - Full local `pnpm test:run` was attempted and is **not green**: its server lane recorded 10,517 passes and 11 failures plus fixture/setup errors. Queue (31 tests), Cursor/Git-load (9 tests), and missing-binary failures cleared on isolated reruns / building the runner test binaries. Two native suites still cannot initialize embedded PostgreSQL on this host. - The remaining native-session recovery assertion was reproduced in a clean worktree at base `a20ecce40` (1 failed, 67 passed across the native/queue suites). It expects a settled-session error but receives a semantic-tool-input digest error. No server or runner files changed in this PR. - All substantive CI jobs have passed, including build, typecheck, all server/workspace test shards, all three e2e shards, and the canary dry run. The unchanged Slack ordering test exhausted its one-second wait on the first run; its shard passed on rerun. Final aggregate verification passed: **31 passing checks**, no failures or pending checks; two optional Storybook deployment/visual checks were skipped. Greptile is **5/5**, with no unresolved review threads. - The supplemental local serialized route run was stopped after CI passed all five serialized shards; it had reported no failures. - The browser fixture uses the real chat rendering components with a plain textarea. It does not test the full composer or server transport. Timing results are local samples; deterministic render-count tests provide normal CI coverage. ## Risks - Closed tool content becomes available to DOM search only after first expansion. Visible run summaries and runtime request receipts remain available immediately. - Opened run history remains mounted to preserve child state. The first full markdown render still scales with conversation size. - Memo dependencies must stay current when adding render inputs. Tests check content edits and replacement gallery callbacks. - No API, database, or permission changes. ## Model Used OpenAI GPT-6 (Codex). Exact serving variant and context-window size are not exposed in this session. Used reasoning, repository tools, code execution, and browser testing. No sub-agents were used. ## Checklist - [x] I have included a thinking path that traces from project context to this change - [x] I have specified the model used (with version and capability details) - [x] I have checked ROADMAP.md and confirmed this PR does not duplicate planned core work - [x] I have searched GitHub for duplicate or related PRs and linked them above - [x] I have either (a) linked existing issues with `Fixes: #` / `Closes #` / `Refs #` OR (b) described the issue in-PR following the relevant issue template - [x] I have not referenced internal/instance-local Paperclip issues or links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip` URLs) - [x] My branch name describes the change (e.g. `docs/...`, `fix/...`) and contains no internal Paperclip ticket id or instance-derived details - [ ] I have run tests locally and they pass — targeted/UI/workspace checks pass; the full local server suite has the baseline/host failures documented above - [x] I have added or updated tests where applicable - [x] I have updated relevant documentation to reflect my changes - [x] I have considered and documented any risks above - [x] All Paperclip CI gates are green - [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups - [x] I will address all Greptile and reviewer comments before requesting merge Co-authored-by: Paperclip <noreply@paperclip.ing> |
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| README.md | ||
| playwright.config.ts | ||
| scrollback.spec.ts | ||
README.md
Task chat scrollback regression
Run from the repository root:
pnpm exec playwright test --config tests/perf/task-chat/playwright.config.ts
The test starts an isolated Vite server on port 4197. It needs no database,
credentials, or running agents. It renders the real TaskChatThreadView, bubbles,
markdown, run folds, and scroller with 200 long responses and 4,000 historical
tool entries. A synthetic live tail updates ten times per second. A second case
recreates the history objects on each update, as transcript projection can do.
The harness uses a plain reply textarea; it does not test the full task composer
or server-to-browser transport.
Chromium samples main-thread task time for three seconds. Both cases must stay below 50% main-thread utilization and deliver at least 20 updates. The ceiling leaves room for machine variation while detecting the original saturation. Performance JSON is attached to each test result. The test also checks reading position during updates, typing, return to latest, lazy tool inspection, and preserved tool expansion across closing/reopening a run.
For manual inspection, start the same server and open
http://127.0.0.1:4197/tests/task-chat-perf.html:
pnpm --filter @paperclipai/ui exec vite --host 127.0.0.1 --port 4197 --strictPort
This HTML entry is not part of the shipped application build.
Reproduction and results
On macOS Chromium against commit a05b828bc, the original code consumed 97.8%
of the main thread and delivered 8 updates. With the fix, the same dev fixture
consumed 11.6% for tail-only updates and 31.5% for recreated history, delivering
32 updates in both cases. These are local samples, not cross-machine promises.
The normal Vitest suite includes deterministic guards in
TaskChatThreadView.performance.test.tsx and TaskChatTurn.test.tsx: unchanged
history does not rerender or reparse markdown, changed content/gallery callbacks
remain current, and collapsed tools mount on demand. These run in ordinary CI;
the browser performance test is opt-in.