Fix ghost terminals after using "Developer: Restart Extension Host"

src/process.ts

@@ -14,6 +14,8 @@ export class PowerShellProcess {
     // This is used to warn the user that the extension is taking longer than expected to startup.
     private static warnUserThreshold = 30;
 
+    private static title = "PowerShell Extension";
+
     public onExited: vscode.Event<void>;
     private onExitedEmitter?: vscode.EventEmitter<void>;
 
@@ -25,7 +27,7 @@ export class PowerShellProcess {
     constructor(
         public exePath: string,
         private bundledModulesPath: string,
-        private title: string,
+        private isTemp: boolean,
         private logger: ILogger,
         private startPsesArgs: string,
         private sessionFilePath: vscode.Uri,
@@ -99,7 +101,7 @@ export class PowerShellProcess {
 
         // Launch PowerShell in the integrated terminal
         const terminalOptions: vscode.TerminalOptions = {
-            name: this.title,
+            name: this.isTemp ? `${PowerShellProcess.title} (TEMP)` : PowerShellProcess.title,
             shellPath: this.exePath,
             shellArgs: powerShellArgs,
             cwd: await validateCwdSetting(this.logger),
@@ -127,6 +129,17 @@ export class PowerShellProcess {
         return await this.waitForSessionFile(cancellationToken);
     }
 
+    // This function is used to clean-up stale PowerShell Extension terminals,
+    // which can happen with `restartExtensionHost` is called because we are
+    // unable to finish diposing before we're gone.
+    public static cleanUpTerminals(): void {
+        for (const terminal of vscode.window.terminals) {
+            if (terminal.name.startsWith(PowerShellProcess.title)) {
+                terminal.dispose();
+            }
+        }
+    }
+
     // This function should only be used after a failure has occurred because it is slow!
     public async getVersionCli(): Promise<string> {
         const exec = promisify(cp.execFile);

src/session.ts

@@ -350,7 +350,7 @@ export class SessionManager implements Middleware {
             new PowerShellProcess(
                 this.PowerShellExeDetails.exePath,
                 bundledModulesPath,
-                "[TEMP] PowerShell Extension",
+                true,
                 this.logger,
                 this.getEditorServicesArgs(bundledModulesPath, this.PowerShellExeDetails) + "-DebugServiceOnly ",
                 this.getNewSessionFilePath(),
@@ -528,11 +528,14 @@ export class SessionManager implements Middleware {
         cancellationToken: vscode.CancellationToken): Promise<PowerShellProcess> {
 
         const bundledModulesPath = await this.getBundledModulesPath();
+
+        // Dispose any stale terminals from previous killed sessions.
+        PowerShellProcess.cleanUpTerminals();
         const languageServerProcess =
             new PowerShellProcess(
                 powerShellExeDetails.exePath,
                 bundledModulesPath,
-                "PowerShell Extension",
+                false,
                 this.logger,
                 this.getEditorServicesArgs(bundledModulesPath, powerShellExeDetails),
                 this.getNewSessionFilePath(),