Make xtab modelConfiguration an advanced setting

extensions/copilot/package.json

@@ -4008,6 +4008,18 @@
 			{
 				"id": "advanced",
 				"properties": {
+					"github.copilot.chat.inlineEdits.xtabProvider.modelConfiguration": {
+						"type": [
+							"object",
+							"null"
+						],
+						"default": null,
+						"markdownDescription": "Advanced model configuration for the next edit suggestions xtab provider.\n\n**Note**: This is an advanced setting.",
+						"tags": [
+							"advanced",
+							"experimental"
+						]
+					},
 					"github.copilot.chat.reasoningEffortOverride": {
 						"type": [
 							"string",

extensions/copilot/src/platform/configuration/common/configurationService.ts

@@ -721,6 +721,13 @@ export namespace ConfigKey {
 
 		/** Internal: override reasoning/thinking effort sent to model APIs (e.g. Responses API, Messages API). Used by evals. */
 		export const ReasoningEffortOverride = defineSetting<string | null>('chat.reasoningEffortOverride', ConfigType.Simple, null);
+
+		export const InlineEditsXtabProviderModelConfiguration = (() => {
+			const oldKey = 'chat.advanced.inlineEdits.xtabProvider.modelConfiguration';
+			const newKey = 'chat.inlineEdits.xtabProvider.modelConfiguration';
+			migrateSetting(newKey, oldKey);
+			return defineSetting<xtabPromptOptions.ModelConfiguration | null>(newKey, ConfigType.Simple, null, xtabPromptOptions.MODEL_CONFIGURATION_VALIDATOR, { oldKey });
+		})();
 	}
 
 	/**
@@ -749,7 +756,6 @@ export namespace ConfigKey {
 		export const InlineEditsNextCursorPredictionApiKey = defineTeamInternalSetting<string | undefined>('chat.advanced.inlineEdits.nextCursorPrediction.apiKey', ConfigType.Simple, undefined, vString());
 		export const InlineEditsXtabProviderUrl = defineTeamInternalSetting<string | undefined>('chat.advanced.inlineEdits.xtabProvider.url', ConfigType.Simple, undefined, vString());
 		export const InlineEditsXtabProviderApiKey = defineTeamInternalSetting<string | undefined>('chat.advanced.inlineEdits.xtabProvider.apiKey', ConfigType.Simple, undefined, vString());
-		export const InlineEditsXtabProviderModelConfiguration = defineTeamInternalSetting<xtabPromptOptions.ModelConfiguration | undefined>('chat.advanced.inlineEdits.xtabProvider.modelConfiguration', ConfigType.Simple, undefined, xtabPromptOptions.MODEL_CONFIGURATION_VALIDATOR);
 		export const InlineEditsNextCursorPredictionLintOptions = defineTeamInternalSetting<Partial<xtabPromptOptions.LintOptions> | undefined>('chat.advanced.inlineEdits.nextCursorPrediction.lintOptions', ConfigType.Simple, undefined, xtabPromptOptions.LINT_OPTIONS_VALIDATOR);
 		export const InlineEditsInlineCompletionsEnabled = defineTeamInternalSetting<boolean>('chat.advanced.inlineEdits.inlineCompletions.enabled', ConfigType.Simple, true, vBoolean());
 		export const InlineEditsInlineCompletionsAdvanced = defineTeamInternalSetting<boolean>('chat.advanced.inlineEdits.inlineCompletions.advancedDetection', ConfigType.ExperimentBased, true, vBoolean());

extensions/copilot/src/platform/configuration/vscode/test/configurationServiceImpl.spec.ts

@@ -0,0 +1,75 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { describe, expect, test, vi } from 'vitest';
+
+const { mockConfigStore } = vi.hoisted(() => ({
+	mockConfigStore: { user: {} as Record<string, unknown>, defaults: {} as Record<string, unknown> },
+}));
+
+vi.mock('vscode', () => {
+	function makeConfig(prefix: string) {
+		const fullKey = (k: string) => prefix ? `${prefix}.${k}` : k;
+		return {
+			get<T>(k: string): T | undefined {
+				const fk = fullKey(k);
+				if (fk in mockConfigStore.user) {
+					return mockConfigStore.user[fk] as T;
+				}
+				if (fk in mockConfigStore.defaults) {
+					return mockConfigStore.defaults[fk] as T;
+				}
+				return undefined;
+			},
+			inspect<T>(k: string) {
+				const fk = fullKey(k);
+				return {
+					key: fk,
+					defaultValue: mockConfigStore.defaults[fk] as T | undefined,
+					globalValue: (fk in mockConfigStore.user ? mockConfigStore.user[fk] : undefined) as T | undefined,
+				};
+			},
+		};
+	}
+	return {
+		workspace: {
+			getConfiguration: (prefix: string) => makeConfig(prefix),
+			onDidChangeConfiguration: () => ({ dispose() { } }),
+		},
+	};
+});
+
+import { ICopilotTokenStore } from '../../../authentication/common/copilotTokenStore';
+import { ConfigKey } from '../../common/configurationService';
+import { ConfigurationServiceImpl } from '../configurationServiceImpl';
+
+const fakeTokenStore: ICopilotTokenStore = {
+	copilotToken: undefined,
+	onDidStoreUpdate: () => ({ dispose() { } }),
+} as any;
+
+describe('ConfigurationServiceImpl - migrated chat.advanced setting fallback', () => {
+	test('reads the user-set OLD key when only the OLD key is configured', () => {
+		const oldKey = `github.copilot.${ConfigKey.Advanced.InlineEditsXtabProviderModelConfiguration.oldId}`;
+		const newKey = ConfigKey.Advanced.InlineEditsXtabProviderModelConfiguration.fullyQualifiedId;
+
+		const userValue = {
+			modelName: 'dd_5minichat_edits_xtab_300_small',
+			promptingStrategy: 'xtab275',
+			includeTagsInCurrentFile: false,
+		};
+
+		mockConfigStore.user = { [oldKey]: userValue };
+		// The new key is registered with `type: ["object", "null"]` and `default: null`,
+		// so an unconfigured user reads `null` for the new key, allowing the
+		// `?? config.get(oldKey)` fallback to take over.
+		mockConfigStore.defaults = { [newKey]: null };
+
+		const svc = new ConfigurationServiceImpl(fakeTokenStore);
+		const value = svc.getConfig(ConfigKey.Advanced.InlineEditsXtabProviderModelConfiguration);
+
+		expect(value).toEqual(userValue);
+	});
+});

extensions/copilot/src/platform/inlineEdits/node/inlineEditsModelService.ts

@@ -75,7 +75,7 @@ export class InlineEditsModelService extends Disposable implements IInlineEditsM
 	private _fetchedModelsObs = observableFromEvent(this, this._proxyModelsService.onModelListUpdated, () => this._proxyModelsService.nesModels);
 
 	private _preferredModelNameObs = this._configService.getExperimentBasedConfigObservable(ConfigKey.Advanced.InlineEditsPreferredModel, this._expService);
-	private _localModelConfigObs = this._configService.getConfigObservable(ConfigKey.TeamInternal.InlineEditsXtabProviderModelConfiguration);
+	private _localModelConfigObs = this._configService.getConfigObservable(ConfigKey.Advanced.InlineEditsXtabProviderModelConfiguration);
 	private _expBasedModelConfigObs = this._configService.getExperimentBasedConfigObservable(ConfigKey.TeamInternal.InlineEditsXtabProviderModelConfigurationString, this._expService);
 	private _defaultModelConfigObs = this._configService.getExperimentBasedConfigObservable(ConfigKey.TeamInternal.InlineEditsXtabProviderDefaultModelConfigurationString, this._expService);
 	private _useSlashModelsObs = this._configService.getExperimentBasedConfigObservable(ConfigKey.TeamInternal.InlineEditsUseSlashModels, this._expService);
@@ -210,7 +210,7 @@ export class InlineEditsModelService extends Disposable implements IInlineEditsM
 		}: {
 			copilotToken: CopilotToken | undefined;
 			fetchedNesModels: WireTypes.Model.t[] | undefined;
-			localModelConfig: ModelConfiguration | undefined;
+			localModelConfig: ModelConfiguration | null;
 			modelConfigString: string | undefined;
 			defaultModelConfigString: string | undefined;
 			useSlashModels: boolean;

extensions/copilot/test/base/simulationOptions.ts

@@ -254,7 +254,7 @@ export class SimulationOptions {
 			``,
 			`Global options (placed before 'nes-datagen'):`,
 			`  --config-file                      Path to a JSON config file (required for nes-datagen)`,
-			`                                     Must include "chat.advanced.inlineEdits.xtabProvider.modelConfiguration"`,
+			`                                     Must include "github.copilot.chat.inlineEdits.xtabProvider.modelConfiguration"`,
 			`                                     with at least { "modelName", "promptingStrategy", "includeTagsInCurrentFile" }`,
 			`  -p, --parallelism                  Number of parallel workers (default: 20)`,
 			`  --verbose                          Print detailed progress and error information`,

extensions/copilot/test/pipeline/pipeline.ts

@@ -84,7 +84,7 @@ export async function runInputPipeline(opts: RunPipelineOptions, log = console.l
 		await configService.setConfig(ConfigKey.TeamInternal.InlineEditsExtraDebounceEndOfLine, 0);
 		await configService.setConfig(ConfigKey.TeamInternal.InlineEditsExtraDebounceInlineSuggestion, 0);
 
-		const modelConfig = configService.getConfig(ConfigKey.TeamInternal.InlineEditsXtabProviderModelConfiguration);
+		const modelConfig = configService.getConfig(ConfigKey.Advanced.InlineEditsXtabProviderModelConfiguration);
 		const responseFormat = ResponseFormat.fromPromptingStrategy(modelConfig?.promptingStrategy);
 
 		log(`  Local model configuration: ${JSON.stringify(modelConfig)}`);

extensions/copilot/test/pipeline/test/fixtures/config.json

@@ -1,5 +1,5 @@
 {
-	"github.copilot.chat.advanced.inlineEdits.xtabProvider.modelConfiguration": {
+	"github.copilot.chat.inlineEdits.xtabProvider.modelConfiguration": {
 		"modelName": "test-model",
 		"promptingStrategy": "patchBased02",
 		"includeTagsInCurrentFile": true,