Do not start TypeSpec Language Server when there is no workspace opened

.chronus/changes/no-lsp-error-without-workspace-2024-11-19-18-43-58.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - typespec-vscode
+---
+
+Do not start TypeSpec Language Server when there is no workspace opened

packages/typespec-vscode/src/extension.ts

@@ -50,13 +50,13 @@ export async function activate(context: ExtensionContext) {
       async (args: RestartServerCommandArgs | undefined): Promise<TspLanguageClient> => {
         return vscode.window.withProgress(
           {
-            title: "Restarting TypeSpec language service...",
+            title: args?.notificationMessage ?? "Restarting TypeSpec language service...",
             location: vscode.ProgressLocation.Notification,
           },
           async () => {
             if (args?.forceRecreate === true) {
               logger.info("Forcing to recreate TypeSpec LSP server...");
-              return await recreateLSPClient(context, args?.popupRecreateLspError);
+              return await recreateLSPClient(context);
             }
             if (client && client.state === State.Running) {
               await client.restart();
@@ -65,7 +65,7 @@ export async function activate(context: ExtensionContext) {
               logger.info(
                 "TypeSpec LSP server is not running which is not expected, try to recreate and start...",
               );
-              return recreateLSPClient(context, args?.popupRecreateLspError);
+              return recreateLSPClient(context);
             }
           },
         );
@@ -97,26 +97,33 @@ export async function activate(context: ExtensionContext) {
     }),
   );
 
-  return await vscode.window.withProgress(
-    {
-      title: "Launching TypeSpec language service...",
-      location: vscode.ProgressLocation.Notification,
-    },
-    async () => {
-      await recreateLSPClient(context);
-    },
-  );
+  // Only try to start language server when some workspace has been opened
+  // because the LanguageClient class will popup error notification in vscode directly if failing to start
+  // which will be confusing to user if no workspace is opened (i.e. in Create TypeSpec project scenario)
+  if ((vscode.workspace.workspaceFolders?.length ?? 0) > 0) {
+    return await vscode.window.withProgress(
+      {
+        title: "Launching TypeSpec language service...",
+        location: vscode.ProgressLocation.Notification,
+      },
+      async () => {
+        await recreateLSPClient(context);
+      },
+    );
+  } else {
+    logger.info("No workspace opened, Skip starting TypeSpec language service.");
+  }
 }
 
 export async function deactivate() {
   await client?.stop();
 }
 
-async function recreateLSPClient(context: ExtensionContext, showPopupWhenError?: boolean) {
+async function recreateLSPClient(context: ExtensionContext) {
   logger.info("Recreating TypeSpec LSP server...");
   const oldClient = client;
   client = await TspLanguageClient.create(context, outputChannel);
   await oldClient?.stop();
-  await client.start(showPopupWhenError ?? (vscode.workspace.workspaceFolders?.length ?? 0) > 0);
+  await client.start();
   return client;
 }

packages/typespec-vscode/src/tsp-language-client.ts

@@ -142,9 +142,10 @@ export class TspLanguageClient {
     }
   }
 
-  async start(showPopupWhenError: boolean): Promise<void> {
+  async start(): Promise<void> {
     try {
       if (this.client.needsStart()) {
+        // please be aware that this method would popup error notification in vscode directly
         await this.client.start();
         logger.info("TypeSpec server started");
       } else {
@@ -162,13 +163,13 @@ export class TspLanguageClient {
             " - TypeSpec server path is configured with https://github.com/microsoft/typespec#installing-vs-code-extension.",
           ].join("\n"),
           [],
-          { showOutput: false, showPopup: showPopupWhenError },
+          { showOutput: false, showPopup: true },
         );
         logger.error("Error detail", [e]);
       } else {
         logger.error("Unexpected error when starting TypeSpec server", [e], {
           showOutput: false,
-          showPopup: showPopupWhenError,
+          showPopup: true,
         });
       }
     }

packages/typespec-vscode/src/types.ts

@@ -19,12 +19,36 @@ export interface InstallGlobalCliCommandArgs {
   confirm: boolean;
   confirmTitle?: string;
   confirmPlaceholder?: string;
+  /**
+   * set to true to disable popup notification and show output channel when running the command
+   */
+  silentMode?: boolean;
 }
 
 export interface RestartServerCommandArgs {
   /**
    * whether to recreate TspLanguageClient instead of just restarting it
    */
   forceRecreate: boolean;
-  popupRecreateLspError: boolean;
+  notificationMessage?: string;
 }
+
+export const enum ResultCode {
+  Success = "success",
+  Fail = "fail",
+  Cancelled = "cancelled",
+  Timeout = "timeout",
+}
+
+interface SuccessResult<T> {
+  code: ResultCode.Success;
+  value: T;
+  details?: any;
+}
+
+interface UnsuccessResult {
+  code: ResultCode.Fail | ResultCode.Cancelled | ResultCode.Timeout;
+  details?: any;
+}
+
+export type Result<T> = SuccessResult<T> | UnsuccessResult;

packages/typespec-vscode/src/utils.ts

@@ -6,6 +6,7 @@ import { CancellationToken } from "vscode";
 import { Executable } from "vscode-languageclient/node.js";
 import logger from "./log/logger.js";
 import { isUrl } from "./path-utils.js";
+import { ResultCode } from "./types.js";
 
 export async function isFile(path: string) {
   try {
@@ -278,8 +279,8 @@ export function spawnExecution(
 }
 
 /**
- * if the operation is cancelled, the promise will be rejected with reason==="cancelled"
- * if the operation is timeout, the promise will be rejected with reason==="timeout"
+ * if the operation is cancelled, the promise will be rejected with {@link ResultCode.Cancelled}
+ * if the operation is timeout, the promise will be rejected with {@link ResultCode.Timeout}
  *
  * @param action
  * @param token
@@ -293,10 +294,10 @@ export function createPromiseWithCancelAndTimeout<T>(
 ) {
   return new Promise<T>((resolve, reject) => {
     token.onCancellationRequested(() => {
-      reject("cancelled");
+      reject(ResultCode.Cancelled);
     });
     setTimeout(() => {
-      reject("timeout");
+      reject(ResultCode.Timeout);
     }, timeoutInMs);
     action.then(resolve, reject);
   });