fix(electrobun): partial Codex #3 fixes — message persistence race, double-start guard

ui-electrobun/src/mainview/agent-store.svelte.ts

@@ -121,6 +121,8 @@ const cleanupTimers = new Map<string, ReturnType<typeof setTimeout>>();
 const msgPersistTimers = new Map<string, ReturnType<typeof setTimeout>>();
 // Fix #12: Track last persisted index per session to avoid re-saving entire history
 const lastPersistedIndex = new Map<string, number>();
+// Fix #2 (Codex audit): Guard against double-start race
+const startingProjects = new Set<string>();
 
 // ── Session persistence helpers ─────────────────────────────────────────────
 
@@ -153,6 +155,8 @@ function persistMessages(session: AgentSession): void {
     const startIdx = lastPersistedIndex.get(session.sessionId) ?? 0;
     const newMsgs = session.messages.slice(startIdx);
     if (newMsgs.length === 0) return;
+    // Fix #1 (Codex audit): Snapshot batch end BEFORE async save to avoid race
+    const batchEnd = session.messages.length;
     const msgs = newMsgs.map((m) => ({
       sessionId: session.sessionId,
       msgId: m.id,
@@ -163,7 +167,7 @@ function persistMessages(session: AgentSession): void {
       timestamp: m.timestamp,
     }));
     appRpc.request['session.messages.save']({ messages: msgs }).then(() => {
-      lastPersistedIndex.set(session.sessionId, session.messages.length);
+      lastPersistedIndex.set(session.sessionId, batchEnd);
     }).catch((err: unknown) => {
       console.error('[session.messages.save] persist error:', err);
     });
@@ -434,6 +438,25 @@ export async function startAgent(
 ): Promise<{ ok: boolean; error?: string }> {
   ensureListeners();
 
+  // Fix #2 (Codex audit): Prevent double-start race
+  if (startingProjects.has(projectId)) {
+    return { ok: false, error: 'Session start already in progress' };
+  }
+  startingProjects.add(projectId);
+
+  try {
+    return await _startAgentInner(projectId, provider, prompt, options);
+  } finally {
+    startingProjects.delete(projectId);
+  }
+}
+
+async function _startAgentInner(
+  projectId: string,
+  provider: string,
+  prompt: string,
+  options: StartOptions,
+): Promise<{ ok: boolean; error?: string }> {
   // If there's an existing done/error session for this project, clear it first
   clearSession(projectId);
 
@@ -583,6 +606,16 @@ export function clearSession(projectId: string): void {
  */
 export async function loadLastSession(projectId: string): Promise<boolean> {
   ensureListeners();
+
+  // Fix #5 (Codex audit): Don't overwrite an active (running/starting) session
+  const existingSessionId = projectSessionMap.get(projectId);
+  if (existingSessionId) {
+    const existing = sessions[existingSessionId];
+    if (existing && (existing.status === 'running' || startingProjects.has(projectId))) {
+      return false;
+    }
+  }
+
   try {
     const { session } = await appRpc.request['session.load']({ projectId });
     if (!session) return false;
@@ -628,5 +661,65 @@ export async function loadLastSession(projectId: string): Promise<boolean> {
   }
 }
 
+// ── Fix #14 (Codex audit): Session memory management ─────────────────────────
+
+const MAX_SESSIONS_PER_PROJECT = 5;
+
+/**
+ * Purge a session entirely from the sessions map.
+ * Call when a project is deleted or to free memory.
+ */
+export function purgeSession(sessionId: string): void {
+  delete sessions[sessionId];
+  lastPersistedIndex.delete(sessionId);
+  clearStallTimer(sessionId);
+  const pendingTimer = msgPersistTimers.get(sessionId);
+  if (pendingTimer) {
+    clearTimeout(pendingTimer);
+    msgPersistTimers.delete(sessionId);
+  }
+  const cleanupTimer = cleanupTimers.get(sessionId);
+  if (cleanupTimer) {
+    clearTimeout(cleanupTimer);
+    cleanupTimers.delete(sessionId);
+  }
+}
+
+/**
+ * Purge all sessions for a project.
+ * Call when a project is removed from the workspace.
+ */
+export function purgeProjectSessions(projectId: string): void {
+  const sessionId = projectSessionMap.get(projectId);
+  if (sessionId) {
+    purgeSession(sessionId);
+    projectSessionMap.delete(projectId);
+  }
+  // Also purge any orphaned sessions for this project
+  for (const [sid, session] of Object.entries(sessions)) {
+    if (session.projectId === projectId) {
+      purgeSession(sid);
+    }
+  }
+}
+
+/** Enforce max sessions per project — keep only the most recent N. */
+function enforceMaxSessions(projectId: string): void {
+  const projectSessions = Object.entries(sessions)
+    .filter(([, s]) => s.projectId === projectId && s.status !== 'running')
+    .sort(([, a], [, b]) => {
+      const aTs = a.messages[a.messages.length - 1]?.timestamp ?? 0;
+      const bTs = b.messages[b.messages.length - 1]?.timestamp ?? 0;
+      return bTs - aTs; // newest first
+    });
+
+  if (projectSessions.length > MAX_SESSIONS_PER_PROJECT) {
+    const toRemove = projectSessions.slice(MAX_SESSIONS_PER_PROJECT);
+    for (const [sid] of toRemove) {
+      purgeSession(sid);
+    }
+  }
+}
+
 /** Initialize listeners on module load. */
 ensureListeners();