Skip to content

🐛 fix: prevent Markdown stream replay when vlist remounts streaming items#14086

Merged
Innei merged 3 commits into
canaryfrom
fix/markdown-stream-replay-on-vlist-remount
Apr 23, 2026
Merged

🐛 fix: prevent Markdown stream replay when vlist remounts streaming items#14086
Innei merged 3 commits into
canaryfrom
fix/markdown-stream-replay-on-vlist-remount

Conversation

@Innei

@Innei Innei commented Apr 23, 2026

Copy link
Copy Markdown
Member

💻 Change Type

  • 🐛 fix

🔀 Description of Change

Long streaming assistant replies replayed their token-by-token Markdown animation whenever users scrolled them out of view and back in. Root cause: virtua's `VList` recycles off-screen items, so the streaming `MarkdownMessage` lost its animation state on remount and replayed from the beginning.

Fix: pin currently-streaming items in the vlist via `keepMounted`.

  • `VirtualizedList.tsx` computes `keepMountedIndices` from `messageStateSelectors.isMessageGenerating` (already per-block — the store associates the running operation to the streaming write-target's DB message id, i.e. the block id), and passes them to `VList`'s `keepMounted` prop.
  • Streaming items now stay mounted regardless of scroll position; the Markdown component keeps its animation state across any scroll, so no replay.

An earlier version of this PR also drilled an `animated` prop down through `AssistantGroup` → `GroupItem` → `ContentBlock` → `MessageContent` → `useMarkdown`. That was redundant: `useMarkdown(blockId)` already resolves to `generating=false` for finalized blocks and `true` only for the active streaming block. The prop drilling has been reverted in the follow-up commit, keeping only the `keepMounted` change.

🧪 How to Test

  1. Send a prompt that produces a long streaming markdown reply (multi-paragraph / code blocks).
  2. While streaming, scroll the conversation to the top.
  3. Scroll back down.
  4. Expected: the streaming message continues smoothly; no replay of the typewriter animation on already-rendered content.
  • Tested locally
  • Added/updated tests
  • No tests needed

`bunx vitest run 'src/features/Conversation/Messages/AssistantGroup'` → 27/27 pass.

📸 Screenshots / Videos

N/A (visual behavior only — no DOM structure change).

📝 Additional Information

  • No public API change.
  • `keepMounted` is supported by the pinned `virtua@^0.48.3` version.

…tems

Long streaming replies replayed the token-by-token animation when users
scrolled them out of view and back. virtua VList was recycling streaming
items, so the Markdown component lost its animation state on remount.

- Pin currently-streaming messages via `keepMounted` on the VList so
  their DOM stays mounted regardless of scroll position.
- Scope the `animated` flag to the last answer segment inside an
  AssistantGroup. Finalized blocks now render as static markdown, so any
  future remount cannot replay completed content.
@vercel

vercel Bot commented Apr 23, 2026

Copy link
Copy Markdown

The latest updates on your projects. Learn more about Vercel for GitHub.

Project Deployment Actions Updated (UTC)
lobehub Ready Ready Preview, Comment Apr 23, 2026 8:45am

Request Review

@dosubot dosubot Bot added size:M This PR changes 30-99 lines, ignoring generated files. 🐛 Bug labels Apr 23, 2026

@sourcery-ai sourcery-ai Bot left a comment

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

We've reviewed this pull request using the Sourcery rules engine

The store already exposes per-block streaming state via
`isMessageGenerating(blockId)`: the streaming write target's
DB message id (== block.id) is associated to the running operation,
so finalized blocks naturally resolve to `generating=false` and the
active block to `true`. The prop drilling added in the prior commit
only duplicated this and did not actually prevent replay on the
streaming block itself.

Keep the real fix (`keepMounted` on the VList) which pins the
streaming item so vlist recycling never resets the Markdown
animation state in the first place.
@codecov

codecov Bot commented Apr 23, 2026

Copy link
Copy Markdown

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.14%. Comparing base (decbc4c) to head (2cbe751).
⚠️ Report is 3 commits behind head on canary.

Additional details and impacted files
@@           Coverage Diff           @@
##           canary   #14086   +/-   ##
=======================================
  Coverage   67.14%   67.14%           
=======================================
  Files        2133     2133           
  Lines      182487   182487           
  Branches    18823    18818    -5     
=======================================
  Hits       122531   122531           
  Misses      59831    59831           
  Partials      125      125           
Flag Coverage Δ
app 59.75% <ø> (ø)
database 92.23% <ø> (ø)
packages/agent-runtime 79.82% <ø> (ø)
packages/context-engine 83.10% <ø> (ø)
packages/conversation-flow 92.40% <ø> (ø)
packages/file-loaders 87.02% <ø> (ø)
packages/memory-user-memory 74.74% <ø> (ø)
packages/model-bank 99.89% <ø> (ø)
packages/model-runtime 84.07% <ø> (ø)
packages/prompts 70.14% <ø> (ø)
packages/python-interpreter 92.90% <ø> (ø)
packages/ssrf-safe-fetch 0.00% <ø> (ø)
packages/utils 88.41% <ø> (ø)
packages/web-crawler 88.66% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Components Coverage Δ
Store 66.59% <ø> (ø)
Services 51.94% <ø> (ø)
Server 66.58% <ø> (ø)
Libs 52.50% <ø> (ø)
Utils 80.09% <ø> (ø)
🚀 New features to boost your workflow:
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
  • 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

@dosubot dosubot Bot added size:S This PR changes 10-29 lines, ignoring generated files. and removed size:M This PR changes 30-99 lines, ignoring generated files. labels Apr 23, 2026
Recycling a virtualized item whose node hosts a Selection anchor or
focus silently drops the user's highlight. Track message ids that
currently contain an active selection via a `selectionchange` listener
and merge their indices into `keepMountedIndices` alongside the
streaming pins.

- New hook `useSelectionMessageIds` walks Selection range endpoints up
  to the nearest `[data-message-id]` host and returns a stable Set of
  ids, returning the previous reference when the set is unchanged.
- VirtualizedList merges selection indices with streaming indices and
  hands the union to VList's `keepMounted`.
@dosubot dosubot Bot added size:M This PR changes 30-99 lines, ignoring generated files. and removed size:S This PR changes 10-29 lines, ignoring generated files. labels Apr 23, 2026
@Innei Innei merged commit 50ffa5b into canary Apr 23, 2026
49 of 50 checks passed
@Innei Innei deleted the fix/markdown-stream-replay-on-vlist-remount branch April 23, 2026 09:24
@arvinxx arvinxx mentioned this pull request Apr 27, 2026
arvinxx added a commit that referenced this pull request Apr 27, 2026
# 🚀 LobeHub v2.1.53 (20260427)

**Release Date:** April 27, 2026
**Since v2.1.52:** 194 merged PRs · 17 contributors

> Introduce Heterogeneous Agent — Claude Code and Codex run as
first-class desktop runtimes, paired with a new Agent Signal package,
sharper desktop UX, and a wave of flagship model additions.

---

## ✨ Highlights

- **Introduce Heterogeneous Agent** — Claude Code and Codex run as
first-class desktop agents: subagent rendering, partial-message
streaming, multi-turn resume, terminal error surfacing, rich tool
inspectors, and runtime polish. (#14162, #13754, #14067, #14001, #13970,
#13942)
- **Screen capture & Quick Chat tray** — New desktop screen capture
overlay (macOS permission-gated) with Quick Chat tray and upload
pipeline improvements; chat input auto-focuses on overlay mount.
(#13818, #14097, #14105)
- **Desktop topic & tab UX** — Dedicated topic popup window with
cross-window sync, Cmd+W/Cmd+T tab shortcuts, TabBar polish, recent
working directories expanded to 20, and human approval notifications.
(#13957, #13983, #13972, #14036, #14092)
- **Git workflow built-in** — One-click pull/push from the branch chip,
ahead/behind badge, and submodule/worktree repo detection. (#14041,
#13980, #13978)
- **Agent Signal package** — New `@lobechat/agent-signal` runtime for
dynamic memory feedback signals, with OTel metrics and self-iteration in
Lab. (#14157, #14170, #14159, #14169, #14187)
- **New models** — Claude Opus 4.7 with `xhigh` effort tier, GPT-5.5,
DeepSeek V4 Flash/Pro with reasoning slider, Kimi K2.6, MiMo-V2.5/Pro,
gpt-image-2, Qwen3.6 Flash/Plus, and Pixverse-c1. (#13903, #14147,
#14114, #14004, #14089, #14039, #13923)
- **New providers** — OpenCode Zen, OpenCode Go, and Azure OpenAI Router
runtime. (#13943, #14064, #13823)
- **Mobile settings overhaul** — Full settings menu and responsive
profile layout for mobile. (#14019)

---

## 🏗️ Heterogeneous Agent

- Claude Code runtime, working-directory awareness, and sidebar polish.
(#13970)
- CC subagent rendering with persistent streamed text; parallel-tool
orphan fix. (#14001, #13968, #14024)
- Per-step usage persisted to each step assistant message. (#13964)
- Per-phase workflow expand defaults; full-expand toggle with
three-level expansion. (#14171, #13906)
- Hetero-mode actions bar; tool inspector polish. (#13963, #14034,
#14030)
- Codex desktop integration with rich tool rendering and devtools
preview. (#14067, #14100)
- Codex terminal error surfacing and CLI output tracing. (#14166)
- Tighten `isCanUseVision` default and add aggregator fallback. (#14172)
- Persist `ccSessionId` in topic metadata for CC multi-turn resume.
(#13902)
- CC account card, topic filter, and integration polish. (#13955,
#13942, #13950)
- Token-level deltas streamed via `--include-partial-messages`. (#13929)

---

## 🧠 Agent Signal & Self-Iteration

- New `@lobechat/agent-signal` package with dynamic feedback signals.
(#14157)
- AgentSignalRuntime wired through agent-tracing and observability-otel
metrics. (#14170, #14159)
- Self-iteration feature flag added to Lab; front-side flag check.
(#14169, #14186)
- Signal policy for receiving memory feedback dynamically. (#14187)

---

## 💬 Conversation

- Queue follow-up sends during running CC turns. (#14179)
- Persist per-topic chat scroll position; pin user message + fold long
messages. (#14191, #14056)
- Inline resend when editing last user message. (#14080)
- Disable first-block markdown streaming to prevent flicker. (#14193,
#13904)
- Prevent Markdown stream replay when vlist remounts streaming items.
(#14086)
- Stop repinning after manual scroll; unify scroll-to-user + spacer
hooks. (#14099, #14132)

---

## 📱 Platforms & Integrations

### Desktop / Electron

- Screen capture overlay, Quick Chat tray, and upload pipeline
improvements. (#13818)
- macOS permission gate for screen capture; auto-focus chat panel input.
(#14097, #14105)
- Dedicated topic popup window with cross-window sync. (#13957)
- TabBar polish: `+` button for new topic, dark theme blend, close icon
by default. (#13972, #14203, #13973)
- Recent working directories expanded from 5 to 20; submodule/worktree
repo detection. (#14036, #13978)
- Cmd+W / Cmd+T tab shortcuts and global shortcut consolidation.
(#13983, #13880)
- Linux icon configuration; human approval desktop notifications.
(#14042, #14092)

### Git Workflow

- One-click pull/push from branch chip; ahead/behind badge with
refactored GitCtr. (#14041, #13980)

### Mobile

- Full settings menu and responsive profile layout. (#14019)
- Agent route added to mobile router; mobile agent topic route
registered. (#14103, #14158)
- Session list skeleton row layout corrected. (#14040)

### Bot / Messaging

- DM strategy support; bot emoji and markdown render optimization.
(#14201, #14091, #14140)
- Slack webhook fix; bot platform setup guide reference. (#14052,
#14121)

---

## 🤖 Models & Providers

### New models

- **Claude Opus 4.7** with `xhigh` effort tier; strip temperature/top_p.
(#13903, #13909)
- **GPT-5.5**. (#14147)
- **DeepSeek V4** Flash/Pro cards with reasoning slider; cache-hit and
Pro discount pricing. (#14114, #14209, #14196, #14131)
- **Kimi K2.6** model with LobeHub-hosted card. (#14004, #14006)
- **MiMo-V2.5 / V2.5-Pro**. (#14089)
- **gpt-image-2**, **Qwen3.6 Flash/Plus**, **Pixverse-c1**. (#14039,
#13923)

### New providers

- **OpenCode Zen** and **OpenCode Go** with env-var support. (#13943,
#14064)
- **Azure OpenAI Router** runtime support. (#13823)
- Model alias mapping for image and video runtimes. (#13896)
- Seedance video models migrated to Dreamina. (#14144)

### Runtime reliability

- Sanitize invalid tool_call arguments to unbreak strict providers.
(#14033)
- Tolerate null `function.name` in streaming tool_call deltas. (#14139)
- Preserve Gemini 3 `thoughtSignature` in `call_tools_batch`
normalization. (#14032)
- Downgrade `image_url` parts when target model lacks vision. (#14029)
- Preserve Cloudflare provider error context. (#14136)
- Use `safety_identifier` for OpenAI Responses API. (#14148)
- Unwrap underlying PG error in `formatErrorEventData`. (#14038)

---

## 🖥️ User Experience

- **Onboarding** — Preset agent naming suggestions, structured hunk ops
for `updateDocument`, persona analytics snapshot, footer promotion
pipeline, wrap-up button. (#13931, #13989, #13930, #13853, #13934)
- **Document workflow** — Agent documents promoted as primary workspace
panel; history management and compare workflow; web-crawl docs
associated with agent documents. (#13924, #13725, #13893)
- **cmdk** — Agent identity surfaced on topic search results;
topic/message search scoped to current agent. (#14204, #13960)
- **Floating chat panel** and workspace improvements. (#13887)
- **Topic completion status** with dropdown action and filter. (#14005)

---

## 🔧 Tooling

- Redis-backed feature flag provider for runtime config. (#14098)
- Vite upgraded to 8.0.0 with Rolldown strict execution order. (#12720,
#14058)
- `@lobechat/model-bank` automated npm release with provenance. (#14015,
#14017, #14018)
- Skill activation fallback when `activateTools` cannot find identifier.
(#14010)
- Cron tool: timezone and existing jobs injected into system prompt;
clarified `lobe-gtd` and `lobe-cron` descriptions. (#14012, #14013)

---

## 🔒 Security & Reliability

- **Security:** uuid bumped to v14 (advisory). (#14083)
- **Security:** validate avatar URL and scope old-avatar deletion to
owner. (#13982)
- **Security:** clear OIDC sessions on better-auth signout; return 401
(not 500) for expired OIDC JWT. (#13916, #14014)
- **Reliability:** scope pending-approval check to current assistant
turn. (#14182)
- **Reliability:** sanitize heterogeneous-agent attachment cache
filenames. (#13937)
- **Reliability:** reduce subagent task status error noise. (#14026)

---

## 👥 Contributors

Huge thanks to **17 contributors** who shipped **194 merged PRs** this
week.

@hardy · @shaun0927 · @hezhijie0327 · @sxjeru · @arvinxx · @Innei ·
@tjx666 · @lijian · @neko · @rdmclin2 · @AmAzing129 · @sudongyuer ·
@CanisMinor · @rivertwilight

Plus @lobehubbot and renovate[bot] for maintenance.

---

**Full Changelog**:
v2.1.52...v2.1.53
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

🐛 Bug size:M This PR changes 30-99 lines, ignoring generated files.

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant