Repopulate slash command in chat input editor (#187207)

* Repopulate slash command in chat input editor

src/vs/workbench/contrib/chat/browser/contrib/chatInputEditorContrib.ts

@@ -21,6 +21,7 @@ import { IChatWidget, IChatWidgetService } from 'vs/workbench/contrib/chat/brows
 import { ChatWidget } from 'vs/workbench/contrib/chat/browser/chatWidget';
 import { LifecyclePhase } from 'vs/workbench/services/lifecycle/common/lifecycle';
 import { ChatInputPart } from 'vs/workbench/contrib/chat/browser/chatInputPart';
+import { IChatService } from 'vs/workbench/contrib/chat/common/chatService';
 
 const decorationDescription = 'chat';
 const slashCommandPlaceholderDecorationType = 'chat-session-detail';
@@ -131,7 +132,36 @@ class InputEditorDecorations extends Disposable {
 	}
 }
 
-ChatWidget.CONTRIBS.push(InputEditorDecorations);
+class InputEditorSlashCommandFollowups extends Disposable {
+	constructor(
+		private readonly widget: IChatWidget,
+		@IChatService private readonly chatService: IChatService
+	) {
+		super();
+		this._register(this.chatService.onDidCompleteSlashCommand(({ slashCommand, sessionId }) => this.repopulateSlashCommand(slashCommand, sessionId)));
+	}
+
+	private async repopulateSlashCommand(slashCommand: string, sessionId: string) {
+		if (this.widget.viewModel?.sessionId !== sessionId) {
+			return;
+		}
+
+		const slashCommands = await this.widget.getSlashCommands();
+
+		if (this.widget.inputEditor.getValue().trim().length !== 0) {
+			return;
+		}
+
+		if (slashCommands?.find(c => c.command === slashCommand)?.shouldRepopulate) {
+			const value = `/${slashCommand} `;
+			this.widget.inputEditor.setValue(value);
+			this.widget.inputEditor.setPosition({ lineNumber: 1, column: value.length + 1 });
+
+		}
+	}
+}
+
+ChatWidget.CONTRIBS.push(InputEditorDecorations, InputEditorSlashCommandFollowups);
 
 class SlashCommandCompletions extends Disposable {
 	constructor(

src/vs/workbench/contrib/chat/common/chatService.ts

@@ -67,6 +67,7 @@ export interface ISlashCommandProvider {
 
 export interface ISlashCommand {
 	command: string;
+	shouldRepopulate?: boolean;
 	provider?: ISlashCommandProvider;
 	sortText?: string;
 	detail?: string;
@@ -176,6 +177,8 @@ export const IChatService = createDecorator<IChatService>('IChatService');
 export interface IChatService {
 	_serviceBrand: undefined;
 	transferredSessionId: string | undefined;
+
+	onDidCompleteSlashCommand: Event<{ slashCommand: string; sessionId: string }>;
 	registerProvider(provider: IChatProvider): IDisposable;
 	registerSlashCommandProvider(provider: ISlashCommandProvider): IDisposable;
 	getProviderInfos(): IChatProviderInfo[];

src/vs/workbench/contrib/chat/common/chatServiceImpl.ts

@@ -135,6 +135,9 @@ export class ChatService extends Disposable implements IChatService {
 	private readonly _onDidPerformUserAction = this._register(new Emitter<IChatUserActionEvent>());
 	public readonly onDidPerformUserAction: Event<IChatUserActionEvent> = this._onDidPerformUserAction.event;
 
+	private readonly _onDidCompleteSlashCommand = this._register(new Emitter<{ slashCommand: string; sessionId: string }>());
+	public readonly onDidCompleteSlashCommand = this._onDidCompleteSlashCommand.event;
+
 	constructor(
 		@IStorageService private readonly storageService: IStorageService,
 		@ILogService private readonly logService: ILogService,
@@ -472,9 +475,15 @@ export class ChatService extends Disposable implements IChatService {
 					Promise.resolve(provider.provideFollowups(model.session!, CancellationToken.None)).then(followups => {
 						model.setFollowups(request, withNullAsUndefined(followups));
 						model.completeResponse(request);
+						if (usedSlashCommand?.command) {
+							this._onDidCompleteSlashCommand.fire({ slashCommand: usedSlashCommand.command, sessionId: model.sessionId });
+						}
 					});
 				} else {
 					model.completeResponse(request);
+					if (usedSlashCommand?.command) {
+						this._onDidCompleteSlashCommand.fire({ slashCommand: usedSlashCommand.command, sessionId: model.sessionId });
+					}
 				}
 			}
 		});

src/vscode-dts/vscode.proposed.interactive.d.ts

@@ -128,6 +128,7 @@ declare module 'vscode' {
 
 	export interface InteractiveSessionSlashCommand {
 		command: string;
+		shouldRepopulate?: boolean;
 		kind: CompletionItemKind;
 		detail?: string;
 	}