Fix WorktreeCreatedTaskDispatcher overfiring (#318241)

src/vs/sessions/SESSIONS.md

@@ -103,7 +103,7 @@ Each session operates on an **`ISessionWorkspace`** containing one or more **`IS
 
 Workspaces carry a `group` label (e.g., `"Local"`, `"Remote"`) used by the workspace picker to organize entries into tabs via the `SESSION_WORKSPACE_GROUP_LOCAL` / `SESSION_WORKSPACE_GROUP_REMOTE` constants.
 
-Tasks with `runOptions.runOn === "worktreeCreated"` are dispatched client-side only for newly created sessions, after the session reports a concrete `gitRepository.workTreeUri`. Restored sessions and runtimes that declare `capabilities.runsWorktreeCreatedTasks` are skipped so setup tasks are not re-run on window open or double-run with server-side provisioning; untitled placeholders are deferred until they become committed worktree sessions.
+Tasks with `runOptions.runOn === "worktreeCreated"` are dispatched client-side only for sessions that this window has just started. `SessionsManagementService` emits `onDidStartSession` from `sendNewChatRequest` after `provider.sendRequest(...)` commits, and `WorktreeCreatedTaskDispatcher` tracks only those sessions until they report a concrete `gitRepository.workTreeUri`. Restored/synced catalog sessions and runtimes that declare `capabilities.runsWorktreeCreatedTasks` are skipped so setup tasks are not re-run on window open or double-run with server-side provisioning.
 
 ### Session Types
 
@@ -143,6 +143,7 @@ Sessions produce file changes organized into **`ISessionChangeset`** groups —
    → Management service opens the chat widget with that chat's resource
    → Delegates to provider.sendRequest(sessionId, chatResource, options)
    → Provider sends request, returns committed session
+   → Management service fires onDidStartSession(committedSession)
    → isNewChatSession context → false
 
 Agent-host providers seed new-session config from the last values picked in the

src/vs/sessions/contrib/chat/browser/chat.contribution.ts

@@ -89,7 +89,7 @@ Registry.as<IConfigurationRegistry>(ConfigurationExtensions.Configuration).regis
 	properties: {
 		[AGENT_HOST_RUN_WORKTREE_CREATED_TASKS_SETTING]: {
 			type: 'boolean',
-			default: false,
+			default: true,
 			scope: ConfigurationScope.APPLICATION,
 			description: localize('chat.agentHost.runWorktreeCreatedTasks', "Whether to automatically run tasks tagged with `\"runOptions\": { \"runOn\": \"worktreeCreated\" }` when a new agent host session worktree is created. Manual `Run Task` invocations are unaffected."),
 		},

src/vs/sessions/contrib/chat/browser/worktreeCreatedTaskDispatcher.ts

@@ -4,21 +4,21 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { Disposable, DisposableMap, DisposableStore } from '../../../../base/common/lifecycle.js';
-import { autorun } from '../../../../base/common/observable.js';
+import { registerAutorunSelfDisposable } from '../../../../base/common/observable.js';
 import { IConfigurationService } from '../../../../platform/configuration/common/configuration.js';
 import { ILogService } from '../../../../platform/log/common/log.js';
 import { IWorkbenchContribution } from '../../../../workbench/common/contributions.js';
 import { isAgentHostProviderId } from '../../../common/agentHostSessionsProvider.js';
 import { ISession, SessionStatus } from '../../../services/sessions/common/session.js';
-import { ISessionsChangeEvent, ISessionsManagementService } from '../../../services/sessions/common/sessionsManagement.js';
+import { ISessionsManagementService } from '../../../services/sessions/common/sessionsManagement.js';
 import { ISessionsTasksService } from './sessionsTasksService.js';
 
 const LOG_PREFIX = '[WorktreeCreatedTaskDispatcher]';
 
 /**
  * Setting that controls whether `runOptions.runOn === 'worktreeCreated'`
  * tasks are auto-dispatched for agent host sessions when a new worktree is
- * created. Defaults to `false`. Manual `Run Task` invocations are unaffected.
+ * created. Defaults to `true`. Manual `Run Task` invocations are unaffected.
  */
 export const AGENT_HOST_RUN_WORKTREE_CREATED_TASKS_SETTING = 'chat.agentHost.runWorktreeCreatedTasks';
 
@@ -41,7 +41,6 @@ export class WorktreeCreatedTaskDispatcher extends Disposable implements IWorkbe
 	// Track per-session disposables (one per in-flight session subscription) so
 	// we tear them down when the session is removed.
 	private readonly _sessionDisposables = this._register(new DisposableMap<string>());
-	private readonly _dispatchedSessions = new Set<string>();
 
 	constructor(
 		@ISessionsManagementService private readonly _sessionsManagementService: ISessionsManagementService,
@@ -51,55 +50,33 @@ export class WorktreeCreatedTaskDispatcher extends Disposable implements IWorkbe
 	) {
 		super();
 
-		for (const session of this._sessionsManagementService.getSessions()) {
-			this._trackSession(session);
-		}
-
-		this._register(this._sessionsManagementService.onDidChangeSessions(e => this._onDidChangeSessions(e)));
+		this._register(this._sessionsManagementService.onDidStartSession(session => this._trackSession(session)));
+		this._register(this._sessionsManagementService.onDidChangeSessions(e => this._onDidRemoveSessions(e.removed)));
 	}
 
-	private _onDidChangeSessions(e: ISessionsChangeEvent): void {
-		const removedTrackedSessions: ISession[] = [];
-		for (const session of e.removed) {
-			if (this._sessionDisposables.get(session.sessionId) && !this._dispatchedSessions.has(session.sessionId)) {
-				removedTrackedSessions.push(session);
-			}
+	private _onDidRemoveSessions(removed: readonly ISession[]): void {
+		for (const session of removed) {
 			this._sessionDisposables.deleteAndDispose(session.sessionId);
-			this._dispatchedSessions.delete(session.sessionId);
-		}
-		for (const session of e.added) {
-			this._trackSession(session);
-		}
-		const replacement = e.added.length === 0 && e.changed.length === 1 && removedTrackedSessions.length === 1
-			? removedTrackedSessions[0]
-			: undefined;
-		for (const session of e.changed) {
-			this._trackSession(session, replacement?.providerId === session.providerId && replacement.sessionType === session.sessionType);
 		}
 	}
 
-	private _trackSession(session: ISession, allowReadySession = false): void {
+	private _trackSession(session: ISession): void {
 		if (session.capabilities.runsWorktreeCreatedTasks) {
 			// The session's runtime already runs these tasks itself.
 			return;
 		}
 		if (this._sessionDisposables.get(session.sessionId)) {
 			return;
 		}
-		if (!allowReadySession && !this._isPendingWorktreeSession(session)) {
-			return;
-		}
 
 		const store = new DisposableStore();
 		this._sessionDisposables.set(session.sessionId, store);
 
 		// Wait for the session to finish loading and report an actual worktree,
-		// then dispatch any pending worktreeCreated tasks once. Set
-		// `dispatched` synchronously before the await so any re-firing of the
-		// autorun observes it and bails.
-		let dispatched = false;
-		store.add(autorun(reader => {
-			if (session.loading.read(reader) || dispatched) {
+		// then dispatch any pending worktreeCreated tasks once. When dispatched,
+		// dispose the per-session subscription store to tear down this autorun.
+		registerAutorunSelfDisposable(store, reader => {
+			if (session.loading.read(reader)) {
 				return;
 			}
 			if (session.status.read(reader) === SessionStatus.Untitled) {
@@ -108,18 +85,9 @@ export class WorktreeCreatedTaskDispatcher extends Disposable implements IWorkbe
 			if (!session.workspace.read(reader)?.folders.some(folder => !!folder.gitRepository?.workTreeUri)) {
 				return;
 			}
-			dispatched = true;
-			this._dispatchedSessions.add(session.sessionId);
-			void this._dispatchWorktreeCreatedTasks(session);
-		}));
-	}
-
-	private _isPendingWorktreeSession(session: ISession): boolean {
-		return session.status.get() === SessionStatus.Untitled || session.loading.get() || !this._hasWorktree(session);
-	}
-
-	private _hasWorktree(session: ISession): boolean {
-		return session.workspace.get()?.folders.some(folder => !!folder.gitRepository?.workTreeUri) ?? false;
+			this._sessionDisposables.deleteAndDispose(session.sessionId);
+			this._dispatchWorktreeCreatedTasks(session);
+		});
 	}
 
 	private async _dispatchWorktreeCreatedTasks(session: ISession): Promise<void> {