Move to "Auto Detect" in language picker and use smarts in Auto Detect for non-Untitled files

src/vs/workbench/browser/parts/editor/editorStatus.ts

@@ -1121,10 +1121,6 @@ export class ShowLanguageExtensionsAction extends Action {
 	}
 }
 
-interface IDetectedLanguageQuickPickItem extends IQuickPickItem {
-	guessRank: number;
-}
-
 export class ChangeModeAction extends Action {
 
 	static readonly ID = 'workbench.action.editor.changeLanguageMode';
@@ -1165,21 +1161,14 @@ export class ChangeModeAction extends Action {
 		}
 
 		let hasLanguageSupport = !!resource;
-		let detectedLanguages: string[] = [];
 		if (resource?.scheme === Schemas.untitled && !this.textFileService.untitled.get(resource)?.hasAssociatedFilePath) {
 			hasLanguageSupport = false; // no configuration for untitled resources (e.g. "Untitled-1")
-
-			// Detect languages since we are in an untitled file
-			detectedLanguages = await this.languageDetectionService.detectLanguages(resource);
 		}
 
 		// All languages are valid picks
 		const languages = this.modeService.getRegisteredLanguageNames();
 		const picks: QuickPickInput[] = languages.sort()
-			.filter(lang => {
-				const modeId = this.modeService.getModeIdForLanguageName(lang.toLowerCase()) || 'unknown';
-				return (detectedLanguages.indexOf(modeId) === -1);
-			}).map(lang => {
+			.map(lang => {
 				const modeId = this.modeService.getModeIdForLanguageName(lang.toLowerCase()) || 'unknown';
 				const extensions = this.modeService.getExtensions(lang).join(' ');
 				let description: string;
@@ -1221,32 +1210,7 @@ export class ChangeModeAction extends Action {
 		const autoDetectMode: IQuickPickItem = {
 			label: localize('autoDetect', "Auto Detect")
 		};
-
-		if (hasLanguageSupport) {
-			picks.unshift(autoDetectMode);
-		} else if (detectedLanguages) {
-			// Add untitled detected languages
-			let index = detectedLanguages.length - 1;
-			for (const modeId of detectedLanguages.reverse()) {
-				const lang = this.modeService.getLanguageName(modeId) || 'unknown';
-				let description: string;
-				if (currentLanguageId === lang) {
-					description = localize('languageDescriptionCurrent', "({0}) - Current Language", modeId);
-				} else {
-					description = localize('languageDescriptionConfigured', "({0})", modeId);
-				}
-
-				const pick: IDetectedLanguageQuickPickItem = {
-					label: lang,
-					iconClasses: getIconClassesForModeId(modeId),
-					description,
-					guessRank: index--,
-				};
-				picks.unshift(pick);
-			}
-
-			picks.unshift({ type: 'separator', label: localize('detectedLanguagesPicks', "detected languages (identifier)") });
-		}
+		picks.unshift(autoDetectMode);
 
 		const pick = await this.quickInputService.pick(picks, { placeHolder: localize('pickLanguage', "Select Language Mode"), matchOnDescription: true });
 		if (!pick) {
@@ -1280,27 +1244,39 @@ export class ChangeModeAction extends Action {
 
 				// Find mode
 				let languageSelection: ILanguageSelection | undefined;
+				let detectedLanguage: string | undefined;
 				if (pick === autoDetectMode) {
 					if (textModel) {
 						const resource = EditorResourceAccessor.getOriginalUri(activeEditor, { supportSideBySide: SideBySideEditor.PRIMARY });
 						if (resource) {
-							languageSelection = this.modeService.createByFilepathOrFirstLine(resource, textModel.getLineContent(1));
+							// Detect languages since we are in an untitled file
+							let modeId: string | undefined = withNullAsUndefined(this.modeService.getModeIdByFilepathOrFirstLine(resource, textModel.getLineContent(1)));
+							if (!modeId) {
+								detectedLanguage = await this.languageDetectionService.detectLanguage(resource);
+								modeId = detectedLanguage;
+							}
+							if (modeId) {
+								languageSelection = this.modeService.create(modeId);
+							}
 						}
 					}
 				} else {
 					languageSelection = this.modeService.createByLanguageName(pick.label);
-				}
 
-				const guessRankOfPicked: number = (pick as IDetectedLanguageQuickPickItem).guessRank ?? -1;
-				// If we detected languages and they didn't choose the top detected language (which should also be the active language if automatic detection is enabled)
-				// then the automatic language detection was likely wrong and the user is correcting it. In this case, we want telemetry.
-				if (detectedLanguages.length && guessRankOfPicked !== 0) {
-					this.telemetryService.publicLog2<IAutomaticLanguageDetectionLikelyWrongData, AutomaticLanguageDetectionLikelyWrongClassification>(AutomaticLanguageDetectionLikelyWrongId, {
-						// For languages that weren't guessed, the guessRankOfPicked will be -1. This detail tells us if the user chose the language that was guessed or not.
-						choseOtherGuessedLanguage: guessRankOfPicked !== -1,
-						currentLanguageId: currentLanguageId ?? 'unknown',
-						nextLanguageId: languageSelection?.languageIdentifier.language ?? 'unknown'
-					});
+					if (resource) {
+						// fire and forget to not slow things down
+						this.languageDetectionService.detectLanguage(resource).then(detectedModeId => {
+							const chosenModeId = this.modeService.getModeIdForLanguageName(pick.label.toLowerCase()) || 'unknown';
+							if (detectedModeId === currentModeId && currentModeId !== chosenModeId) {
+								// If they didn't choose the detected language (which should also be the active language if automatic detection is enabled)
+								// then the automatic language detection was likely wrong and the user is correcting it. In this case, we want telemetry.
+								this.telemetryService.publicLog2<IAutomaticLanguageDetectionLikelyWrongData, AutomaticLanguageDetectionLikelyWrongClassification>(AutomaticLanguageDetectionLikelyWrongId, {
+									currentLanguageId: currentLanguageId ?? 'unknown',
+									nextLanguageId: pick.label
+								});
+							}
+						});
+					}
 				}
 
 				// Change mode

src/vs/workbench/services/languageDetection/browser/languageDetectionSimpleWorker.ts

@@ -27,16 +27,6 @@ export class LanguageDetectionSimpleWorker extends EditorSimpleWorker {
 	private _loadFailed: boolean = false;
 
 	public async detectLanguage(uri: string): Promise<string | undefined> {
-		const stopWatch = new StopWatch(true);
-		for await (const language of this.detectLanguagesImpl(uri)) {
-			stopWatch.stop();
-			this._host.fhr('sendTelemetryEvent', [[language.languageId], [language.confidence], stopWatch.elapsed()]);
-			return language.languageId;
-		}
-		return undefined;
-	}
-
-	public async detectLanguages(uri: string): Promise<string[]> {
 		const languages: string[] = [];
 		const confidences: number[] = [];
 		const stopWatch = new StopWatch(true);
@@ -46,8 +36,11 @@ export class LanguageDetectionSimpleWorker extends EditorSimpleWorker {
 		}
 		stopWatch.stop();
 
-		this._host.fhr('sendTelemetryEvent', [languages, confidences, stopWatch.elapsed()]);
-		return languages;
+		if (languages.length) {
+			this._host.fhr('sendTelemetryEvent', [languages, confidences, stopWatch.elapsed()]);
+			return languages[0];
+		}
+		return undefined;
 	}
 
 	private async getModelOperations(): Promise<ModelOperations> {

src/vs/workbench/services/languageDetection/browser/languageDetectionWorkerServiceImpl.ts

@@ -69,16 +69,6 @@ export class LanguageDetectionService extends Disposable implements ILanguageDet
 		}
 		return undefined;
 	}
-
-	async detectLanguages(resource: URI): Promise<string[]> {
-		const languages: Array<string | undefined> = await this._languageDetectionWorkerClient.detectLanguages(resource);
-		for (let i = 0; i < languages.length; i++) {
-			const modeId = this.getModeId(languages[i]);
-			languages[i] = modeId ? modeId : undefined;
-		}
-
-		return languages.filter(<T>(l?: T): l is T => Boolean(l));
-	}
 }
 
 export interface IWorkerClient<W> {
@@ -196,10 +186,6 @@ export class LanguageDetectionWorkerClient extends EditorWorkerClient {
 		await this._withSyncedResources([resource]);
 		return (await this._getProxy()).detectLanguage(resource.toString());
 	}
-	public async detectLanguages(resource: URI): Promise<string[]> {
-		await this._withSyncedResources([resource]);
-		return (await this._getProxy()).detectLanguages(resource.toString());
-	}
 }
 
 registerSingleton(ILanguageDetectionService, LanguageDetectionService);

src/vs/workbench/services/languageDetection/common/languageDetectionWorkerService.ts

@@ -22,12 +22,6 @@ export interface ILanguageDetectionService {
 	 * @returns the language mode for the given resource or undefined if the model is not confident enough.
 	 */
 	detectLanguage(resource: URI): Promise<string | undefined>;
-
-	/**
-	 * @param resource The resource to detect the language for.
-	 * @returns all possible language modes detected in this resource.
-	 */
-	detectLanguages(resource: URI): Promise<string[]>;
 }
 
 //#region Telemetry events
@@ -35,13 +29,11 @@ export interface ILanguageDetectionService {
 export const AutomaticLanguageDetectionLikelyWrongId = 'automaticlanguagedetection.likelywrong';
 
 export interface IAutomaticLanguageDetectionLikelyWrongData {
-	choseOtherGuessedLanguage: boolean;
 	currentLanguageId: string;
 	nextLanguageId: string;
 }
 
 export type AutomaticLanguageDetectionLikelyWrongClassification = {
-	choseOtherGuessedLanguage: { classification: 'SystemMetaData', purpose: 'FeatureInsight' },
 	currentLanguageId: { classification: 'SystemMetaData', purpose: 'FeatureInsight' },
 	nextLanguageId: { classification: 'SystemMetaData', purpose: 'FeatureInsight' }
 };