Ensure languageServer value is valid, send event during activate (microsoft#13064)

Author: jakebailey

src/client/activation/activationService.ts

@@ -188,7 +188,6 @@ export class LanguageServerExtensionActivationService
         // Configuration is non-default, so `languageServer` should be present.
         const configurationService = this.serviceContainer.get<IConfigurationService>(IConfigurationService);
         const lstType = configurationService.getSettings(this.resource).languageServer;
-        this.sendTelemetryForChosenLanguageServer(lstType).ignoreErrors();
         return lstType === LanguageServerType.Jedi;
     }
 
@@ -253,6 +252,8 @@ export class LanguageServerExtensionActivationService
                 break;
         }
 
+        this.sendTelemetryForChosenLanguageServer(serverType).ignoreErrors();
+
         await this.logStartup(serverType);
         let server = this.serviceContainer.get<ILanguageServerActivator>(ILanguageServerActivator, serverType);
         try {

src/client/common/configSettings.ts

@@ -231,11 +231,12 @@ export class PythonSettings implements IPythonSettings {
             pythonSettings.get<boolean>('autoUpdateLanguageServer', true)
         )!;
 
-        let ls = pythonSettings.get<LanguageServerType>('languageServer');
-        if (!ls) {
+        let ls = pythonSettings.get<LanguageServerType>('languageServer') ?? LanguageServerType.Jedi;
+        ls = systemVariables.resolveAny(ls);
+        if (!Object.values(LanguageServerType).includes(ls)) {
             ls = LanguageServerType.Jedi;
         }
-        this.languageServer = systemVariables.resolveAny(ls)!;
+        this.languageServer = ls;
 
         // tslint:disable-next-line:no-backbone-get-set-outside-model no-non-null-assertion
         this.jediPath = systemVariables.resolveAny(pythonSettings.get<string>('jediPath'))!;

src/test/common/configSettings/configSettings.unit.test.ts

@@ -193,6 +193,31 @@ suite('Python Settings', async () => {
         config.verifyAll();
     });
 
+    function testLanguageServer(languageServer: LanguageServerType, expectedValue: LanguageServerType) {
+        test(languageServer, () => {
+            expected.pythonPath = 'python3';
+            expected.languageServer = languageServer;
+            initializeConfig(expected);
+            config
+                .setup((c) => c.get<LanguageServerType>('languageServer'))
+                .returns(() => expected.languageServer)
+                .verifiable(TypeMoq.Times.once());
+
+            settings.update(config.object);
+
+            expect(settings.languageServer).to.be.equal(expectedValue);
+            config.verifyAll();
+        });
+    }
+
+    suite('languageServer settings', async () => {
+        Object.values(LanguageServerType).forEach(async (languageServer) => {
+            testLanguageServer(languageServer, languageServer);
+        });
+
+        testLanguageServer('invalid' as LanguageServerType, LanguageServerType.Jedi);
+    });
+
     function testExperiments(enabled: boolean) {
         expected.pythonPath = 'python3';
         // tslint:disable-next-line:no-any