Reload open workspace preview when agent mutates that file

Track write/edit tool paths per turn, refresh the open preview on
tool_complete and after preservePreview loadDir on stream done, without
closing preview for unrelated responses or wiping unsaved local edits.

CHANGELOG.md

@@ -3,11 +3,10 @@
 
 ## [Unreleased]
 
-## [v0.51.187] — 2026-05-31 — Release FG (stage-batchG — workspace-preview persistence + repaired-sidecar order + scroll-intent window)
+## [v0.51.187] — 2026-05-31 — Release FG (stage-batchG — workspace-preview persistence + scroll-intent window)
 
 ### Fixed
 - Workspace file preview no longer closes when a chat response finishes and the UI refreshes the workspace file tree. Background `loadDir('.')` on stream `done` now preserves an open preview instead of always calling `clearPreview()`, and reloads the open file when a write/edit tool touched that path during the turn (skipping reload while the preview has unsaved local edits) (#3262, @pamnard).
-- Repaired messaging sidecars now keep their authoritative order when merged with CLI/state rows for display: the sidecar ordering is preserved verbatim and only non-overlapping CLI rows outside the sidecar timestamp window are added, instead of timestamp-sorting the whole union (which replayed older compression-lineage rows into the middle/tail and made repeated user turns reappear after reload) (#3268, @ai-ag2026).
 - During streaming, scrolling up to read earlier content no longer snaps back to the bottom after a brief pause: the upward-scroll intent window was widened from 450ms to 2000ms so DOM-layout changes from the markdown parser / tool-card insertions are still recognized as co-occurring with user intent and don't re-pin the view. Downward scroll, the scroll-to-bottom button, and trackpad-momentum protection are unaffected (#3250, @emanon312).
 
 ## [v0.51.186] — 2026-05-31 — Release FF (stage-batchF — update-checker ff-reachability fall-through + utf-8 git-output test coverage)

static/messages.js

@@ -684,6 +684,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
   }
   closeOtherLiveStreams(activeSid);
   closeLiveStream(activeSid);
+  if(!reconnecting&&typeof resetTurnWorkspaceMutations==='function') resetTurnWorkspaceMutations();
 
   // On reconnect, restore accumulated text from INFLIGHT so we don't lose
   // progress made before the session switch. Without this the closure starts
@@ -1710,8 +1711,10 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
       if(d.duration!==undefined) tc.duration=d.duration;
       S.toolCalls=inflight.toolCalls;
       persistInflightState();
+      if(typeof noteWorkspaceMutationsFromToolCall==='function') noteWorkspaceMutationsFromToolCall(tc);
       if(S.session&&S.session.session_id===activeSid&&typeof scheduleRenderSessionArtifacts==='function') scheduleRenderSessionArtifacts();
       if(!S.session||S.session.session_id!==activeSid) return;
+      if(typeof refreshOpenPreviewIfMutated==='function') refreshOpenPreviewIfMutated();
       appendLiveToolCard(tc);
       snapshotLiveTurn();
       scrollIfPinned();
@@ -1974,6 +1977,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
           if(isSessionViewed) _markSessionViewed(completedSid, completedSession.message_count ?? S.messages.length);
           syncTopbar();renderMessages({preserveScroll:true});
           if(shouldFollowOnDone&&typeof scrollToBottom==='function') scrollToBottom();
+          if(typeof noteWorkspaceMutationsFromToolCalls==='function') noteWorkspaceMutationsFromToolCalls(S.toolCalls);
           loadDir('.', { preservePreview: true });
           // TTS auto-read: speak the last assistant response if enabled (#499)
           if(typeof autoReadLastAssistant==='function') setTimeout(()=>autoReadLastAssistant(), 300);

static/workspace.js

@@ -223,6 +223,37 @@ function _artifactCandidatesFromToolCall(tc){
   return out;
 }
 
+const _turnMutatedPreviewPaths = new Set();
+
+function resetTurnWorkspaceMutations(){
+  _turnMutatedPreviewPaths.clear();
+}
+
+function noteWorkspaceMutationsFromToolCall(tc){
+  for(const a of _artifactCandidatesFromToolCall(tc)){
+    const path=_normalizeArtifactPath(a.path);
+    if(path) _turnMutatedPreviewPaths.add(path);
+  }
+}
+
+function noteWorkspaceMutationsFromToolCalls(toolCalls){
+  if(!Array.isArray(toolCalls)) return;
+  for(const tc of toolCalls) noteWorkspaceMutationsFromToolCall(tc);
+}
+
+function _isOpenPreviewPathMutated(){
+  if(!_previewCurrentPath) return false;
+  const current=_normalizeArtifactPath(_previewCurrentPath);
+  return !!(current&&_turnMutatedPreviewPaths.has(current));
+}
+
+async function refreshOpenPreviewIfMutated(){
+  if(typeof _previewDirty!=='undefined'&&_previewDirty) return;
+  if(!_isOpenPreviewPathMutated()) return;
+  if(!_previewCurrentPath||!S.session) return;
+  await openFile(_previewCurrentPath, { bustCache: true });
+}
+
 function collectSessionArtifacts(){
   const items = [];
   const seen = new Set();
@@ -321,6 +352,8 @@ async function loadDir(path, opts={}){
       }else{
         clearPreview({keepPanelOpen:true});
       }
+    }else if(preservePreview){
+      await refreshOpenPreviewIfMutated();
     }
     // Fetch git info for workspace root (non-blocking)
     if(!path||path==='.') _refreshGitBadge();
@@ -489,9 +522,11 @@ function cancelEditMode(){
   updateEditBtn();
 }
 
-async function openFile(path){
+async function openFile(path, opts={}){
   if(!S.session)return;
   const ext=fileExt(path);
+  const bustCache=!!(opts&&opts.bustCache);
+  const cacheBust=bustCache?`&_=${Date.now()}`:'';
 
   // Binary/download-only formats: trigger browser download, don't preview
   if(DOWNLOAD_EXTS.has(ext)){
@@ -508,14 +543,14 @@ async function openFile(path){
   if(IMAGE_EXTS.has(ext)){
     // Image: load via raw endpoint, show as <img>
     showPreview('image');
-    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}`;
+    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}${cacheBust}`;
     $('previewImg').alt=path;
     $('previewImg').src=url;
     $('previewImg').onerror=()=>setStatus(t('image_load_failed'));
   } else if(AUDIO_EXTS.has(ext)||VIDEO_EXTS.has(ext)){
     const mode=VIDEO_EXTS.has(ext)?'video':'audio';
     showPreview(mode);
-    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}&inline=1`;
+    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}&inline=1${cacheBust}`;
     const wrap=$('previewMediaWrap');
     if(wrap){
       wrap.innerHTML=(typeof _mediaPlayerHtml==='function')
@@ -525,7 +560,7 @@ async function openFile(path){
     }
   } else if(PDF_EXTS.has(ext)){
     showPreview('pdf');
-    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}&inline=1`;
+    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}&inline=1${cacheBust}`;
     const frame=$('previewPdfFrame');
     if(frame){
       frame.src=''; // clear first to avoid stale content
@@ -557,7 +592,7 @@ async function openFile(path){
     // or reading other origin data. If a stricter mode is needed, remove
     // allow-scripts (or add sandbox="") to disable all JS execution.
     showPreview('html');
-    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}&inline=1`;
+    const url=`api/file/raw?session_id=${encodeURIComponent(S.session.session_id)}&path=${encodeURIComponent(path)}&inline=1${cacheBust}`;
     const iframe=$('previewHtmlIframe');
     if(iframe){
       iframe.src=''; // clear first to avoid stale content

tests/test_workspace_preview_preserved_on_stream_done.py

@@ -50,6 +50,9 @@ def test_load_dir_supports_preserve_preview_option():
     assert "if(!preservePreview&&typeofclearPreview" in block.replace(" ", ""), (
         "loadDir() should skip clearPreview() when preservePreview is requested"
     )
+    assert "awaitrefreshOpenPreviewIfMutated()" in block.replace(" ", ""), (
+        "Background refresh must reload the open preview when a mutation tool touched it"
+    )
 
 
 def test_load_dir_still_clears_preview_for_directory_navigation():
@@ -58,3 +61,25 @@ def test_load_dir_still_clears_preview_for_directory_navigation():
     assert "clearPreview({keepPanelOpen:true})" in block.replace(" ", ""), (
         "Directory navigation must still clear previews when preservePreview is not set"
     )
+
+
+def test_turn_mutation_tracking_reloads_open_preview():
+    block = _function_block(WORKSPACE_JS, "refreshOpenPreviewIfMutated")
+    assert "openFile(_previewCurrentPath" in block.replace(" ", ""), (
+        "Mutated open previews must reload through openFile()"
+    )
+    assert "_previewDirty" in block, "Reload must be skipped while the preview has unsaved edits"
+
+
+def test_tool_complete_tracks_workspace_mutations_for_preview_reload():
+    tool_complete_idx = MESSAGES_JS.find("source.addEventListener('tool_complete'")
+    assert tool_complete_idx != -1
+    end = MESSAGES_JS.find("source.addEventListener('approval'", tool_complete_idx)
+    block = MESSAGES_JS[tool_complete_idx:end]
+    assert "noteWorkspaceMutationsFromToolCall" in block
+    assert "refreshOpenPreviewIfMutated" in block
+
+
+def test_stream_start_resets_turn_mutation_tracking():
+    block = _function_block(MESSAGES_JS, "attachLiveStream")
+    assert "resetTurnWorkspaceMutations" in block