Edit mode custom agent (#3773)

* edit mode custom agent

* use AgentConfig

extensions/copilot/src/extension/agents/vscode-node/editModeAgentProvider.ts

@@ -0,0 +1,89 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import { AGENT_FILE_EXTENSION } from '../../../platform/customInstructions/common/promptTypes';
+import { IVSCodeExtensionContext } from '../../../platform/extContext/common/extensionContext';
+import { IFileSystemService } from '../../../platform/filesystem/common/fileSystemService';
+import { ILogService } from '../../../platform/log/common/logService';
+import { Disposable } from '../../../util/vs/base/common/lifecycle';
+import { AgentConfig, buildAgentMarkdown } from './agentTypes';
+
+const BASE_EDIT_MODE_AGENT_CONFIG: AgentConfig = {
+	name: 'Edit',
+	description: 'Edit-only mode restricted to the currently active file and any files explicitly attached in the request context.',
+	argumentHint: 'Describe the edit to apply in the active or attached files',
+	target: 'vscode',
+	disableModelInvocation: true,
+	userInvokable: true,
+	tools: ['read', 'edit'],
+	agents: [],
+	handoffs: [
+		{
+			label: 'Continue with Agent Mode',
+			agent: 'agent',
+			prompt: 'You are now switching to Agent Mode, where you can read and edit any file in the codebase. Continue with the task without the previous restrictions of Edit Mode.',
+			send: true,
+		},
+	],
+	body: `You are a focused allowlist editing agent.
+
+## Rules
+- Allowed files are strictly: (1) the currently active file and (2) files explicitly attached in the request context.
+- Only read and edit files in that allowlist.
+- Create a new file only when the user explicitly asks to create that file.
+- Never create, delete, rename, or modify any file outside that allowlist.
+- Never propose or use terminal commands.
+- If a request requires touching files outside the allowlist, stop and explain that Edit Mode is restricted to the active file plus attached files.
+
+## Workflow
+1. Build the allowed-file set from context: active file + attached files.
+2. Confirm every requested edit target is in that allowed-file set before editing, unless it is an explicitly user-requested new file creation.
+3. Make the minimum required edits only within allowed files.
+4. Summarize exactly what changed and list touched files.
+5. If further changes are needed outside the allowlist, suggest switching to Agent Mode to complete the task without restrictions.`
+};
+
+export class EditModeAgentProvider extends Disposable implements vscode.ChatCustomAgentProvider {
+	readonly label = vscode.l10n.t('Edit Mode Agent');
+
+	private static readonly CACHE_DIR = 'edit-mode-agent';
+	private static readonly AGENT_FILENAME = `EditMode${AGENT_FILE_EXTENSION}`;
+
+	constructor(
+		@IVSCodeExtensionContext private readonly _extensionContext: IVSCodeExtensionContext,
+		@IFileSystemService private readonly _fileSystemService: IFileSystemService,
+		@ILogService private readonly _logService: ILogService,
+	) {
+		super();
+	}
+
+	async provideCustomAgents(
+		_context: unknown,
+		_token: vscode.CancellationToken
+	): Promise<vscode.ChatResource[]> {
+		const content = buildAgentMarkdown(BASE_EDIT_MODE_AGENT_CONFIG);
+		const fileUri = await this._writeCacheFile(content);
+		return [{ uri: fileUri }];
+	}
+
+	private async _writeCacheFile(content: string): Promise<vscode.Uri> {
+		const cacheDir = vscode.Uri.joinPath(
+			this._extensionContext.globalStorageUri,
+			EditModeAgentProvider.CACHE_DIR
+		);
+
+		try {
+			await this._fileSystemService.stat(cacheDir);
+		} catch {
+			await this._fileSystemService.createDirectory(cacheDir);
+		}
+
+		const fileUri = vscode.Uri.joinPath(cacheDir, EditModeAgentProvider.AGENT_FILENAME);
+		await this._fileSystemService.writeFile(fileUri, new TextEncoder().encode(content));
+		this._logService.trace(`[EditModeAgentProvider] Wrote agent file: ${fileUri.toString()}`);
+		return fileUri;
+	}
+}

extensions/copilot/src/extension/agents/vscode-node/promptFileContrib.ts

@@ -5,12 +5,13 @@
 
 import * as vscode from 'vscode';
 import { ConfigKey, IConfigurationService } from '../../../platform/configuration/common/configurationService';
-import { Disposable } from '../../../util/vs/base/common/lifecycle';
+import { Disposable, MutableDisposable } from '../../../util/vs/base/common/lifecycle';
 import { SyncDescriptor } from '../../../util/vs/platform/instantiation/common/descriptors';
 import { IInstantiationService } from '../../../util/vs/platform/instantiation/common/instantiation';
 import { IExtensionContribution } from '../../common/contributions';
 import { AgentCustomizationSkillProvider } from './agentCustomizationSkillProvider';
 import { AskAgentProvider } from './askAgentProvider';
+import { EditModeAgentProvider } from './editModeAgentProvider';
 import { ExploreAgentProvider } from './exploreAgentProvider';
 import { GitHubOrgCustomAgentProvider } from './githubOrgCustomAgentProvider';
 import { GitHubOrgInstructionsProvider } from './githubOrgInstructionsProvider';
@@ -27,6 +28,26 @@ export class PromptFileContribution extends Disposable implements IExtensionCont
 
 		// Register custom agent provider
 		if ('registerCustomAgentProvider' in vscode.chat) {
+			const editModeProviderRegistration = this._register(new MutableDisposable<vscode.Disposable>());
+			const editModeHiddenSetting = 'chat.editMode.hidden';
+			const updateEditModeProvider = () => {
+				const isEditModeHidden = configurationService.getNonExtensionConfig<boolean>(editModeHiddenSetting);
+				if (!isEditModeHidden) {
+					if (!editModeProviderRegistration.value) {
+						editModeProviderRegistration.value = vscode.chat.registerCustomAgentProvider(instantiationService.createInstance(EditModeAgentProvider));
+					}
+				} else {
+					editModeProviderRegistration.clear();
+				}
+			};
+
+			updateEditModeProvider();
+			this._register(configurationService.onDidChangeConfiguration(e => {
+				if (e.affectsConfiguration(editModeHiddenSetting)) {
+					updateEditModeProvider();
+				}
+			}));
+
 			// Only register the provider if the setting is enabled
 			if (configurationService.getConfig(ConfigKey.EnableOrganizationCustomAgents)) {
 				const githubOrgAgentProvider: vscode.ChatCustomAgentProvider = instantiationService.createInstance(new SyncDescriptor(GitHubOrgCustomAgentProvider));