Add call to setupTelemetryEnvironmentAsync (#5922)

* Add call to setupTelemetryEnvironmentAsync

* Make optional

Author: Andrew Hall

src/csharpDevKitExports.ts

@@ -13,5 +13,5 @@ export interface CSharpDevKitExports {
     components: Readonly<{ [key: string]: string }>;
     hasServerProcessLoaded: () => boolean;
     serverProcessLoaded: vscode.Event<void>;
-    writeCommonPropsAsync: (context: vscode.ExtensionContext) => Promise<string | undefined>;
+    setupTelemetryEnvironmentAsync: (env: NodeJS.ProcessEnv) => Promise<string | undefined>;
 }

src/lsptoolshost/roslynLanguageServer.ts

@@ -409,6 +409,8 @@ export class RoslynLanguageServer {
 
             const csharpDevkitArgs = await this.getCSharpDevkitExportArgs(csharpDevkitExtension, options);
             args = args.concat(csharpDevkitArgs);
+
+            await this.setupDevKitEnvironment(env, csharpDevkitExtension);
         } else {
             // C# Dev Kit is not installed - continue C#-only activation.
             _channel.appendLine('Activating C# standalone...');
@@ -528,6 +530,21 @@ export class RoslynLanguageServer {
         return csharpIntelliCodeArgs;
     }
 
+    private async setupDevKitEnvironment(
+        env: NodeJS.ProcessEnv,
+        csharpDevkitExtension: vscode.Extension<CSharpDevKitExports>
+    ): Promise<void> {
+        const exports: CSharpDevKitExports = await csharpDevkitExtension.activate();
+
+        // setupTelemetryEnvironmentAsync was a later addition to devkit (not in preview 1)
+        // so it may not exist in whatever version of devkit the user has installed
+        if (!exports.setupTelemetryEnvironmentAsync) {
+            return;
+        }
+
+        await exports.setupTelemetryEnvironmentAsync(env);
+    }
+
     private getLanguageServicesDevKitComponentPath(csharpDevKitExports: CSharpDevKitExports): string {
         return path.join(
             csharpDevKitExports.components['@microsoft/visualstudio-languageservices-devkit'],