Add when clause support to languageModelChatProviders contribution (microsoft#272299)

* Initial plan

* Add when clause support to languageModelChatProviders contribution

Co-authored-by: lramos15 <4544166+lramos15@users.noreply.github.com>

* Use contextMatchesRules instead of evaluate for when clause evaluation

Co-authored-by: lramos15 <4544166+lramos15@users.noreply.github.com>

* Fix test failure by using separate test suite with proper lifecycle

Co-authored-by: lramos15 <4544166+lramos15@users.noreply.github.com>

* Fix when clause evaluation in tests by implementing contextMatchesRules

Co-authored-by: lramos15 <4544166+lramos15@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: lramos15 <4544166+lramos15@users.noreply.github.com>
Co-authored-by: Logan Ramos <lramos15@gmail.com>

Author: Copilot

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

@@ -15,7 +15,7 @@ import { ThemeIcon } from '../../../../base/common/themables.js';
 import { URI } from '../../../../base/common/uri.js';
 import { localize } from '../../../../nls.js';
 import { IConfigurationService } from '../../../../platform/configuration/common/configuration.js';
-import { IContextKey, IContextKeyService } from '../../../../platform/contextkey/common/contextkey.js';
+import { ContextKeyExpr, IContextKey, IContextKeyService } from '../../../../platform/contextkey/common/contextkey.js';
 import { ExtensionIdentifier } from '../../../../platform/extensions/common/extensions.js';
 import { createDecorator } from '../../../../platform/instantiation/common/instantiation.js';
 import { ILogService } from '../../../../platform/log/common/log.js';
@@ -279,6 +279,10 @@ const languageModelChatProviderType: IJSONSchema = {
 		managementCommand: {
 			type: 'string',
 			description: localize('vscode.extension.contributes.languageModels.managementCommand', "A command to manage the language model chat provider, e.g. 'Manage Copilot models'. This is used in the chat model picker. If not provided, a gear icon is not rendered during vendor selection.")
+		},
+		when: {
+			type: 'string',
+			description: localize('vscode.extension.contributes.languageModels.when', "Condition which must be true to show this language model chat provider in the Manage Models list.")
 		}
 	}
 };
@@ -287,6 +291,7 @@ export interface IUserFriendlyLanguageModel {
 	vendor: string;
 	displayName: string;
 	managementCommand?: string;
+	when?: string;
 }
 
 export const languageModelChatProviderExtensionPoint = ExtensionsRegistry.registerExtensionPoint<IUserFriendlyLanguageModel | IUserFriendlyLanguageModel[]>({
@@ -320,6 +325,7 @@ export class LanguageModelsService implements ILanguageModelsService {
 	private readonly _resolveLMSequencer = new SequencerByKey<string>();
 	private _modelPickerUserPreferences: Record<string, boolean> = {};
 	private readonly _hasUserSelectableModels: IContextKey<boolean>;
+	private readonly _contextKeyService: IContextKeyService;
 	private readonly _onLanguageModelChange = this._store.add(new Emitter<void>());
 	readonly onDidChangeLanguageModels: Event<void> = this._onLanguageModelChange.event;
 
@@ -332,6 +338,7 @@ export class LanguageModelsService implements ILanguageModelsService {
 		@IChatEntitlementService private readonly _chatEntitlementService: IChatEntitlementService,
 	) {
 		this._hasUserSelectableModels = ChatContextKeys.languageModelsAreUserSelectable.bindTo(_contextKeyService);
+		this._contextKeyService = _contextKeyService;
 		this._modelPickerUserPreferences = this._storageService.getObject<Record<string, boolean>>('chatModelPickerPreferences', StorageScope.PROFILE, this._modelPickerUserPreferences);
 		// TODO @lramos15 - Remove after a few releases, as this is just cleaning a bad storage state
 		const entitlementChangeHandler = () => {
@@ -411,7 +418,13 @@ export class LanguageModelsService implements ILanguageModelsService {
 	}
 
 	getVendors(): IUserFriendlyLanguageModel[] {
-		return Array.from(this._vendors.values());
+		return Array.from(this._vendors.values()).filter(vendor => {
+			if (!vendor.when) {
+				return true; // No when clause means always visible
+			}
+			const whenClause = ContextKeyExpr.deserialize(vendor.when);
+			return whenClause ? this._contextKeyService.contextMatchesRules(whenClause) : false;
+		});
 	}
 
 	getLanguageModelIds(): string[] {

src/vs/workbench/contrib/chat/test/common/languageModels.test.ts

@@ -19,6 +19,7 @@ import { TestChatEntitlementService, TestStorageService } from '../../../../test
 import { Event } from '../../../../../base/common/event.js';
 import { MockContextKeyService } from '../../../../../platform/keybinding/test/common/mockKeybindingService.js';
 import { TestConfigurationService } from '../../../../../platform/configuration/test/common/testConfigurationService.js';
+import { ContextKeyExpression } from '../../../../../platform/contextkey/common/contextkey.js';
 
 suite('LanguageModels', function () {
 
@@ -198,4 +199,94 @@ suite('LanguageModels', function () {
 
 		await request.result;
 	});
+
+	test('when clause defaults to true when omitted', async function () {
+		const vendors = languageModels.getVendors();
+		// Both test-vendor and actual-vendor have no when clause, so they should be visible
+		assert.ok(vendors.length >= 2);
+		assert.ok(vendors.some(v => v.vendor === 'test-vendor'));
+		assert.ok(vendors.some(v => v.vendor === 'actual-vendor'));
+	});
+});
+
+suite('LanguageModels - When Clause', function () {
+
+	class TestContextKeyService extends MockContextKeyService {
+		override contextMatchesRules(rules: ContextKeyExpression): boolean {
+			if (!rules) {
+				return true;
+			}
+			// Simple evaluation based on stored keys
+			const keys = rules.keys();
+			for (const key of keys) {
+				const contextKey = this.getContextKeyValue(key);
+				// If the key exists and is truthy, the rule matches
+				if (contextKey) {
+					return true;
+				}
+			}
+			return false;
+		}
+	}
+
+	let languageModelsWithWhen: LanguageModelsService;
+	let contextKeyService: TestContextKeyService;
+
+	setup(function () {
+		contextKeyService = new TestContextKeyService();
+		contextKeyService.createKey('testKey', true);
+
+		languageModelsWithWhen = new LanguageModelsService(
+			new class extends mock<IExtensionService>() {
+				override activateByEvent(name: string) {
+					return Promise.resolve();
+				}
+			},
+			new NullLogService(),
+			new TestStorageService(),
+			contextKeyService,
+			new TestConfigurationService(),
+			new TestChatEntitlementService()
+		);
+
+		const ext = ExtensionsRegistry.getExtensionPoints().find(e => e.name === languageModelChatProviderExtensionPoint.name)!;
+
+		ext.acceptUsers([{
+			description: { ...nullExtensionDescription },
+			value: { vendor: 'visible-vendor', displayName: 'Visible Vendor' },
+			collector: null!
+		}, {
+			description: { ...nullExtensionDescription },
+			value: { vendor: 'conditional-vendor', displayName: 'Conditional Vendor', when: 'testKey' },
+			collector: null!
+		}, {
+			description: { ...nullExtensionDescription },
+			value: { vendor: 'hidden-vendor', displayName: 'Hidden Vendor', when: 'falseKey' },
+			collector: null!
+		}]);
+	});
+
+	teardown(function () {
+		languageModelsWithWhen.dispose();
+	});
+
+	ensureNoDisposablesAreLeakedInTestSuite();
+
+	test('when clause filters vendors correctly', async function () {
+		const vendors = languageModelsWithWhen.getVendors();
+		assert.strictEqual(vendors.length, 2);
+		assert.ok(vendors.some(v => v.vendor === 'visible-vendor'));
+		assert.ok(vendors.some(v => v.vendor === 'conditional-vendor'));
+		assert.ok(!vendors.some(v => v.vendor === 'hidden-vendor'));
+	});
+
+	test('when clause evaluates to true when context key is true', async function () {
+		const vendors = languageModelsWithWhen.getVendors();
+		assert.ok(vendors.some(v => v.vendor === 'conditional-vendor'), 'conditional-vendor should be visible when testKey is true');
+	});
+
+	test('when clause evaluates to false when context key is false', async function () {
+		const vendors = languageModelsWithWhen.getVendors();
+		assert.ok(!vendors.some(v => v.vendor === 'hidden-vendor'), 'hidden-vendor should be hidden when falseKey is false');
+	});
 });