Update startup logic to handle session failure reasons

These used to be sent given that the logic existed, but the server was
no longer sending them at all. Now that it does, we can handle them.

Author: andyleejordan

src/session.ts

@@ -44,7 +44,6 @@ export enum RunspaceType {
 export interface IEditorServicesSessionDetails {
     status: string;
     reason: string;
-    detail: string;
     powerShellVersion: string;
     channel: string;
     languageServicePort: number;
@@ -430,7 +429,7 @@ export class SessionManager implements Middleware {
 
     private async startPowerShell(): Promise<PowerShellProcess | undefined> {
         if (this.PowerShellExeDetails === undefined) {
-            this.setSessionFailure("Unable to find PowerShell.");
+            void this.setSessionFailedGetPowerShell("Unable to find PowerShell, try installing it?");
             return;
         }
 
@@ -498,10 +497,10 @@ export class SessionManager implements Middleware {
                 void this.setSessionFailedOpenBug("Language client failed to start: " + (err instanceof Error ? err.message : "unknown"));
             }
         } else if (this.sessionDetails.status === "failed") { // Server started but indicated it failed
-            if (this.sessionDetails.reason === "unsupported") {
+            if (this.sessionDetails.reason === "powerShellVersion") {
                 void this.setSessionFailedGetPowerShell(`PowerShell ${this.sessionDetails.powerShellVersion} is not supported, please update!`);
-            } else if (this.sessionDetails.reason === "languageMode") {
-                this.setSessionFailure(`PowerShell language features are disabled due to an unsupported LanguageMode: ${this.sessionDetails.detail}`);
+            } else if (this.sessionDetails.reason === "dotNetVersion") { // Only applies to PowerShell 5.1
+                void this.setSessionFailedGetDotNet(".NET Framework is out-of-date, please install at least 4.8!");
             } else {
                 void this.setSessionFailedOpenBug(`PowerShell could not be started for an unknown reason: ${this.sessionDetails.reason}`);
             }
@@ -728,7 +727,7 @@ Type 'help' to get help.
         try {
             await this.languageClient.start();
         } catch (err) {
-            this.setSessionFailure("Could not start language service: ", err instanceof Error ? err.message : "unknown");
+            void this.setSessionFailedOpenBug("Could not start language service: " + (err instanceof Error ? err.message : "unknown"));
             return;
         }
 
@@ -799,11 +798,6 @@ Type 'help' to get help.
         this.setSessionStatus("Executing...", SessionStatus.Busy);
     }
 
-    private setSessionFailure(message: string, ...additionalMessages: string[]): void {
-        this.setSessionStatus("Initialization Error!", SessionStatus.Failed);
-        void this.logger.writeAndShowError(message, ...additionalMessages);
-    }
-
     private async setSessionFailedOpenBug(message: string): Promise<void> {
         this.setSessionStatus("Initialization Error!", SessionStatus.Failed);
         await this.logger.writeAndShowErrorWithActions(message, [{
@@ -825,6 +819,17 @@ Type 'help' to get help.
         );
     }
 
+    private async setSessionFailedGetDotNet(message: string): Promise<void> {
+        this.setSessionStatus("Initialization Error!", SessionStatus.Failed);
+        await this.logger.writeAndShowErrorWithActions(message, [{
+            prompt: "Open .NET Framework Documentation",
+            action: async (): Promise<void> => {
+                await vscode.env.openExternal(
+                    vscode.Uri.parse("https://dotnet.microsoft.com/en-us/download/dotnet-framework"));
+            }}]
+        );
+    }
+
     private async changePowerShellDefaultVersion(exePath: IPowerShellExeDetails): Promise<void> {
         this.suppressRestartPrompt = true;
         try {