Initial contents for experimentation in typescript-language-features. (#153358)

Co-authored-by: Daniel Rosenwasser <Daniel.Rosenwasser@microsoft.com>

extensions/typescript-language-features/src/experimentationService.ts

@@ -0,0 +1,93 @@
+/*---------------------------------------------------------------------------------------------
+ *  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 VsCodeTelemetryReporter from '@vscode/extension-telemetry';
+import * as tas from 'vscode-tas-client';
+
+interface ExperimentTypes {
+	// None for now.
+}
+
+export class ExperimentationService implements vscode.Disposable {
+	private _experimentationServicePromise: Promise<tas.IExperimentationService>;
+	private _telemetryReporter: ExperimentTelemetryReporter;
+
+	constructor(private readonly _extensionContext: vscode.ExtensionContext) {
+		this._telemetryReporter = new ExperimentTelemetryReporter(_extensionContext);
+		this._experimentationServicePromise = this.createExperimentationService();
+	}
+
+	public async getTreatmentVariable<K extends keyof ExperimentTypes>(name: K, defaultValue: ExperimentTypes[K]): Promise<ExperimentTypes[K]> {
+		const experimentationService = await this._experimentationServicePromise;
+		try {
+			const treatmentVariable = experimentationService.getTreatmentVariableAsync('vscode', name, /*checkCache*/ true) as ExperimentTypes[K];
+			return treatmentVariable;
+		} catch {
+			return defaultValue;
+		}
+	}
+
+	private async createExperimentationService(): Promise<tas.IExperimentationService> {
+		let targetPopulation: tas.TargetPopulation;
+		switch (vscode.env.uriScheme) {
+			case 'vscode':
+				targetPopulation = tas.TargetPopulation.Public;
+			case 'vscode-insiders':
+				targetPopulation = tas.TargetPopulation.Insiders;
+			case 'vscode-exploration':
+				targetPopulation = tas.TargetPopulation.Internal;
+			case 'code-oss':
+				targetPopulation = tas.TargetPopulation.Team;
+			default:
+				targetPopulation = tas.TargetPopulation.Public;
+		}
+
+		const id = this._extensionContext.extension.id;
+		const version = this._extensionContext.extension.packageJSON.version || '';
+		const experimentationService = tas.getExperimentationService(id, version, targetPopulation, this._telemetryReporter, this._extensionContext.globalState);
+		await experimentationService.initialFetch;
+		return experimentationService;
+	}
+
+
+	/**
+	 * @inheritdoc
+	 */
+	public dispose() {
+		this._telemetryReporter.dispose();
+	}
+}
+
+export class ExperimentTelemetryReporter
+	implements tas.IExperimentationTelemetry, vscode.Disposable {
+	private _sharedProperties: Record<string, string> = {};
+	private _reporter: VsCodeTelemetryReporter;
+	constructor(ctxt: vscode.ExtensionContext) {
+		const extension = ctxt.extension;
+		const packageJSON = extension.packageJSON;
+		this._reporter = new VsCodeTelemetryReporter(
+			extension.id,
+			packageJSON.version || '',
+			packageJSON.aiKey || '');
+
+	}
+
+	setSharedProperty(name: string, value: string): void {
+		this._sharedProperties[name] = value;
+	}
+
+	postEvent(eventName: string, props: Map<string, string>): void {
+		const propsObject = {
+			...this._sharedProperties,
+			...Object.fromEntries(props),
+		};
+		this._reporter.sendTelemetryEvent(eventName, propsObject);
+	}
+
+	dispose() {
+		this._reporter.dispose();
+	}
+}