Refactor Copilot CLI session management and improve folder handling

extensions/copilot/src/extension/chatSessions/copilotcli/node/copilotcliSessionService.ts

@@ -78,6 +78,9 @@ export type ICreateSessionOptions = ISessionOptions & { sessionId?: string };
 export interface ICopilotCLISessionService {
 	readonly _serviceBrand: undefined;
 
+	/**
+	 * @deprecated Kept only for non-controller API
+	 */
 	onDidChangeSessions: Event<void>;
 	onDidDeleteSession: Event<string>;
 	onDidChangeSession: Event<ICopilotCLISessionItem>;

extensions/copilot/src/extension/chatSessions/vscode-node/chatSessionMetadataStoreImpl.ts

@@ -158,6 +158,7 @@ export class ChatSessionMetadataStore extends Disposable implements IChatSession
 			await this.writeToGlobalStorage(data);
 		}
 		try {
+			await this.fileSystemService.delete(this.getMetadataFileUri(sessionId));
 			await this.fileSystemService.delete(this.getRequestMappingFileUri(sessionId));
 		} catch {
 			// File may not exist, ignore.

extensions/copilot/src/extension/chatSessions/vscode-node/copilotCLIChatSessionInitializer.ts

@@ -162,7 +162,7 @@ export class CopilotCLIChatSessionInitializer implements ICopilotCLIChatSessionI
 			}
 		} else {
 			// No chat session context (e.g., delegation) - initialize with active repository
-			folderInfo = await this.folderRepositoryManager.initializeFolderRepository(undefined, { stream, toolInvocationToken, isolation: options?.isolation, folder }, token);
+			folderInfo = await this.folderRepositoryManager.initializeFolderRepository(undefined, { stream, toolInvocationToken, isolation: options?.isolation, folder, newBranch: options?.newBranch }, token);
 		}
 
 		if (folderInfo.trusted === false || folderInfo.cancelled) {

extensions/copilot/src/extension/chatSessions/vscode-node/copilotCLIChatSessions.ts

@@ -52,33 +52,6 @@ import { IPullRequestDetectionService } from './pullRequestDetectionService';
 import { getSelectedSessionOptions, ISessionOptionGroupBuilder, OPEN_REPOSITORY_COMMAND_ID, toRepositoryOptionItem, toWorkspaceFolderOptionItem } from './sessionOptionGroupBuilder';
 import { ISessionRequestLifecycle } from './sessionRequestLifecycle';
 
-/**
- * ODO:
- * 3. Verify all command handlers do the exact same thing
- * 6. Is chatSessionContext?.initialSessionOptions still valid with new API
- * 7. Validated selected MRU item
- * 8. We shouldn't have to pass model information into CLISession class, and then update sdk with the model info. Instead when we call get/create session, we should be able to pass the model info there and update the SDK session accordingly.
- * This makes it unnecessary to pass model information.
- * 2. Behavioral Change: trusted flag no longer unlocks dropdowns on trust failure
-In the old code, when sessionResult.trusted === false, there was a call to this.unlockRepoOptionForSession(context, token) to reset dropdown selections. The new code at copilotCLIChatSessions.ts:634 simply returns {} without any dropdown reset. However, lockRepoOptionForSession and unlockRepoOptionForSession were already dead code (commented out), so this is actually correct — removing a no-op.
- *
- * Cases to cover:
- * 1. Hook up the dropdowns for empty workspace folders as well
- * 2. In mult-root workspace we need to display workspace/worktree dropdown along with the repo dropdown
- * 3. Temporarily lock/unlock dropdowns while creating session
- * 4. Lock dropdowns when opening an existing session
- * 5. Browse folders command in empty workspaces
- * 6. Branch dropdown should only be displayed when we select a folder/repo thats a git repo.
- *
- * Test:
- * 1. All of the above
- * 2. Forking sessions
- * 3. Steering messages
- * 4. Queued messages
- * 5. Selecting a new folder in browse folders command should end up with that folder in the dropdown.
- * 6. Delegate from CLI to Cloud
- * 7. Delegate from Local to CLI
- */
 
 export interface ICopilotCLIChatSessionItemProvider extends IDisposable {
 	refreshSession(refreshOptions: { reason: 'update'; sessionId: string } | { reason: 'update'; sessionIds: string[] } | { reason: 'delete'; sessionId: string }): Promise<void>;
@@ -196,6 +169,7 @@ export class CopilotCLIChatSessionContentProvider extends Disposable implements
 				}
 			}
 		));
+		const inputStateForNewSession = new ResourceMap<WeakRef<vscode.ChatSessionInputState>>();
 		controller.newChatSessionItemHandler = async (context) => {
 			const sessionId = this.sessionService.createNewSessionId();
 			const resource = SessionIdForCLI.getResource(sessionId);
@@ -211,6 +185,8 @@ export class CopilotCLIChatSessionContentProvider extends Disposable implements
 
 			controller.items.add(session);
 			this.newSessions.set(resource, session);
+			const groups = await this._optionGroupBuilder.provideChatSessionProviderOptionGroups(context.inputState);
+			inputStateForNewSession.set(resource, new WeakRef(controller.createChatSessionInputState(groups)));
 			return session;
 		};
 		if (this.configurationService.getConfig(ConfigKey.Advanced.CLIForkSessionsEnabled)) {
@@ -273,7 +249,12 @@ export class CopilotCLIChatSessionContentProvider extends Disposable implements
 				const groups = await this._optionGroupBuilder.buildExistingSessionInputStateGroups(sessionResource, token);
 				return controller.createChatSessionInputState(groups);
 			} else {
-				const groups = await this._optionGroupBuilder.provideChatSessionProviderOptionGroups(context.previousInputState);
+				// Possible we've already handled the newChatSessionItemHandler for this same uri
+				// In which case the proper inputState would have been sent.
+				// There's a bug in core where after newChatSessionItemHandler is called, we get
+				// another call for getChatSessionInputState, but this time the previous input state is incorrect.
+				const previousInputState = sessionResource ? inputStateForNewSession.get(sessionResource)?.deref() : undefined;
+				const groups = await this._optionGroupBuilder.provideChatSessionProviderOptionGroups(previousInputState);
 				const state = controller.createChatSessionInputState(groups);
 				// Only wire dynamic updates for new sessions (existing sessions are fully locked).
 				// Note: don't use the getChatSessionInputState token here — it's a one-shot token
@@ -309,7 +290,6 @@ export class CopilotCLIChatSessionContentProvider extends Disposable implements
 	}
 
 	public async updateInputStateAfterFolderSelection(inputState: vscode.ChatSessionInputState, folderUri: vscode.Uri): Promise<void> {
-		this._optionGroupBuilder.setNewFolderForInputState(inputState, folderUri);
 		await this._optionGroupBuilder.rebuildInputState(inputState, folderUri);
 	}
 
@@ -720,6 +700,15 @@ export class CopilotCLIChatSessionParticipant extends Disposable {
 		return { input, attachments };
 	}
 
+	private generateNewBranchName(request: vscode.ChatRequest, token: vscode.CancellationToken): Promise<string | undefined> {
+		const requestTurn = new ChatRequestTurn2(request.prompt ?? '', request.command, [], '', [], [], undefined, undefined, undefined);
+		const fakeContext: vscode.ChatContext = {
+			history: [requestTurn],
+			yieldRequested: false,
+		};
+		const branchNamePromise = (request.prompt && this.branchNameGenerator) ? this.branchNameGenerator.generateBranchName(fakeContext, token) : Promise.resolve(undefined);
+		return branchNamePromise;
+	}
 	private async handleRequestImpl(request: vscode.ChatRequest, context: vscode.ChatContext, stream: vscode.ChatResponseStream, token: vscode.CancellationToken): Promise<vscode.ChatResult | void> {
 		const { chatSessionContext } = context;
 		const disposables = new DisposableStore();
@@ -752,12 +741,7 @@ export class CopilotCLIChatSessionParticipant extends Disposable {
 				return {};
 			}
 
-			const requestTurn = new ChatRequestTurn2(request.prompt ?? '', request.command, [], '', [], [], undefined, undefined, undefined);
-			const fakeContext: vscode.ChatContext = {
-				history: [requestTurn],
-				yieldRequested: false,
-			};
-			const branchNamePromise = (isNewSession && request.prompt && this.branchNameGenerator) ? this.branchNameGenerator.generateBranchName(fakeContext, token) : Promise.resolve(undefined);
+			const branchNamePromise = isNewSession ? this.generateNewBranchName(request, token) : Promise.resolve(undefined);
 
 			if (isNewSession) {
 				this._optionGroupBuilder.lockInputStateGroups(chatSessionContext.inputState);
@@ -869,8 +853,8 @@ export class CopilotCLIChatSessionParticipant extends Disposable {
 			userPrompt = userPrompt || request.prompt;
 			return summary ? `${userPrompt}\n${summary}` : userPrompt;
 		})();
-
-		const { workspaceInfo, cancelled } = await this.sessionInitializer.initializeWorkingDirectory(undefined, { stream }, request.toolInvocationToken, token);
+		const branchNamePromise = this.generateNewBranchName(request, token);
+		const { workspaceInfo, cancelled } = await this.sessionInitializer.initializeWorkingDirectory(undefined, { stream, isolation: IsolationMode.Worktree, newBranch: branchNamePromise }, request.toolInvocationToken, token);
 
 		if (cancelled || token.isCancellationRequested) {
 			stream.markdown(l10n.t('Copilot CLI delegation cancelled.'));
@@ -966,8 +950,8 @@ export function registerCLIChatCommands(
 			);
 
 			if (result === deleteLabel) {
-				await copilotCLISessionService.deleteSession(id);
 				await copilotCliWorkspaceSession.deleteTrackedWorkspaceFolder(id);
+				await copilotCLISessionService.deleteSession(id);
 
 				if (worktreePath) {
 					try {
@@ -1256,7 +1240,7 @@ export function registerCLIChatCommands(
 	}));
 
 	const applyChanges = async (sessionItemOrResource?: vscode.ChatSessionItem | vscode.Uri) => {
-		const resource = sessionItemOrResource instanceof vscode.Uri
+		const resource = isUri(sessionItemOrResource)
 			? sessionItemOrResource
 			: sessionItemOrResource?.resource;
 

extensions/copilot/src/extension/chatSessions/vscode-node/folderRepositoryManagerImpl.ts

@@ -739,7 +739,7 @@ export abstract class FolderRepositoryManager extends Disposable implements IFol
 					deleteFromSource: moveOrCopyChanges === 'move',
 					untracked: true
 				});
-				stream.markdown(l10n.t('Changes migrated to worktree.'));
+				stream.markdown(l10n.t('Changes migrated to worktree.\n'));
 			}
 		} catch (error) {
 			// Continue even if migration fails

extensions/copilot/src/extension/chatSessions/vscode-node/sessionOptionGroupBuilder.ts

@@ -315,7 +315,6 @@ export function folderMRUToChatProviderOptions(mruItems: FolderRepositoryMRUEntr
  */
 export interface ISessionOptionGroupBuilder {
 	readonly _serviceBrand: undefined;
-	setNewFolderForInputState(inputState: vscode.ChatSessionInputState, folderUri: vscode.Uri): void;
 	provideChatSessionProviderOptionGroups(previousInputState: vscode.ChatSessionInputState | undefined): Promise<vscode.ChatSessionProviderOptionGroup[]>;
 	buildBranchOptionGroup(branches: vscode.ChatSessionProviderOptionItem[], headBranchName: string | undefined, isolationEnabled: boolean, currentIsolation: IsolationMode | undefined, previousSelection: vscode.ChatSessionProviderOptionItem | undefined): vscode.ChatSessionProviderOptionGroup | undefined;
 	handleInputStateChange(state: vscode.ChatSessionInputState): Promise<void>;
@@ -340,7 +339,7 @@ export class SessionOptionGroupBuilder implements ISessionOptionGroupBuilder {
 	declare readonly _serviceBrand: undefined;
 	private readonly _getBranchOptionItemsForRepositorySequencer = new SequencerByKey<string>();
 	private readonly _pendingBuildGroups = new WeakMap<vscode.ChatSessionInputState, Promise<vscode.ChatSessionProviderOptionGroup[]>>();
-	// Keeps track of the new folders selected by user, by using folder dialog to select a new folder.
+	// Keeps track of the new folders selected by user
 	private readonly _inputStateNewFolders = new WeakMap<vscode.ChatSessionInputState, vscode.Uri>();
 	constructor(
 		@IGitService private readonly gitService: IGitService,
@@ -354,9 +353,6 @@ export class SessionOptionGroupBuilder implements ISessionOptionGroupBuilder {
 	) { }
 
 
-	setNewFolderForInputState(inputState: vscode.ChatSessionInputState, folderUri: vscode.Uri): void {
-		this._inputStateNewFolders.set(inputState, folderUri);
-	}
 	/**
 	 * Return the git repository for a URI only if the folder is trusted.
 	 * Untrusted folders are treated as non-git.
@@ -409,27 +405,37 @@ export class SessionOptionGroupBuilder implements ISessionOptionGroupBuilder {
 
 			// For untitled workspaces, show last used repositories and "Open Repository..." command
 			const repositories = await this.copilotCLIFolderMruService.getRecentlyUsedFolders(CancellationToken.None);
-			const newFolder = previousInputState ? this._inputStateNewFolders.get(previousInputState) : undefined;
 			items = folderMRUToChatProviderOptions(repositories);
+			const addFolderToList = async (uri: Uri) => {
+				const newFolderRepo = await this.getTrustedRepository(uri, true);
+				const newFolderItem = newFolderRepo
+					? toRepositoryOptionItem(newFolderRepo.rootUri)
+					: toWorkspaceFolderOptionItem(uri, uri.path.split('/').pop() ?? uri.fsPath);
+				// Remove duplicate if already in the list, then add to top
+				items = items.filter(item => item.id !== newFolderItem.id);
+				items.unshift(newFolderItem);
+			};
+			if (selectedFolderUri) {
+				await addFolderToList(selectedFolderUri);
+			}
+			const previouslySelectedUri = previouslySelected ? vscode.Uri.file(previouslySelected.id) : undefined;
+			if (previouslySelectedUri) {
+				await addFolderToList(previouslySelectedUri);
+			}
+			// Ensure previously selected folder is added back into the list of folders.
+			const newFolder = previousInputState ? this._inputStateNewFolders.get(previousInputState) : undefined;
+			if (newFolder) {
+				await addFolderToList(newFolder);
+			}
 			const selectedFolderItem = selectedFolderUri ? items.find(i => i.id === selectedFolderUri.fsPath) : undefined;
+			const previouslySelectedItem = previouslySelected ? items.find(i => i.id === previouslySelected.id) : undefined;
 			const selectedItem = selectedFolderItem
-				?? (previouslySelected
-					? items.find(i => i.id === previouslySelected.id) ?? items[0]
-					: items[0]);
+				?? previouslySelectedItem ?? items[0];
 			if (selectedItem) {
 				defaultRepoUri = vscode.Uri.file(selectedItem.id);
 			}
 
 			items.splice(MAX_MRU_ENTRIES); // Limit to max entries
-			if (newFolder) {
-				const newFolderRepo = await this.getTrustedRepository(newFolder, true);
-				const newFolderItem = newFolderRepo
-					? toRepositoryOptionItem(newFolderRepo.rootUri)
-					: toWorkspaceFolderOptionItem(newFolder, newFolder.path.split('/').pop() ?? newFolder.fsPath);
-				// Remove duplicate if already in the list, then add to top
-				items = items.filter(item => item.id !== newFolderItem.id);
-				items.unshift(newFolderItem);
-			}
 			// If user selected something from the list but it's not there anymore (perhaps its an item at the end of MRU).
 			if (selectedItem && !items.some(item => item.id === selectedItem.id)) {
 				items.push(selectedItem);
@@ -546,6 +552,9 @@ export class SessionOptionGroupBuilder implements ISessionOptionGroupBuilder {
 		if (!optionGroupsEqual(state.groups, newGroups)) {
 			state.groups = newGroups;
 		}
+		if (selectedFolderUri) {
+			this._inputStateNewFolders.set(state, selectedFolderUri);
+		}
 	}
 
 	/**