Add option to disable devkit

package.json

@@ -1169,6 +1169,12 @@
             "default": null,
             "description": "Sets a path where MSBuild binary logs are written to when loading projects, to help diagnose loading errors."
           },
+          "dotnet.loadProjectsWithCSharpExtension": {
+            "scope": "machine-overridable",
+            "type": "boolean",
+            "default": false,
+            "description": "%configuration.dotnet.loadProjectsWithCSharpExtension%"
+          },
           "dotnet.implementType.insertionBehavior": {
             "type": "string",
             "enum": [

package.nls.json

@@ -5,6 +5,7 @@
   "configuration.dotnet.server.waitForDebugger": "Passes the --debug flag when launching the server to allow a debugger to be attached. (Previously `omnisharp.waitForDebugger`)",
   "configuration.dotnet.server.trace": "Sets the logging level for the language server",
   "configuration.dotnet.server.extensionPaths": "Override for path to language server --extension arguments",
+  "configuration.dotnet.loadProjectsWithCSharpExtension": "Forces projects to load with the C# extension only.  This can be useful when using legacy project types that are not supported by the C# Dev Kit. (Requires window reload)",
   "configuration.dotnet.implementType.insertionBehavior": "The insertion location of properties, events, and methods When implement interface or abstract class.",
   "configuration.dotnet.implementType.insertionBehavior.withOtherMembersOfTheSameKind": "Place them with other members of the same kind.",
   "configuration.dotnet.implementType.insertionBehavior.atTheEnd": "Place them at the end.",

src/lsptoolshost/roslynLanguageServer.ts

@@ -403,7 +403,7 @@ export class RoslynLanguageServer {
     }
 
     private async sendOrSubscribeForServiceBrokerConnection(): Promise<void> {
-        const csharpDevKitExtension = vscode.extensions.getExtension<CSharpDevKitExports>(csharpDevkitExtensionId);
+        const csharpDevKitExtension = getCSharpDevKit();
         if (csharpDevKitExtension) {
             const exports = await csharpDevKitExtension.activate();
 
@@ -469,7 +469,7 @@ export class RoslynLanguageServer {
         // Get the brokered service pipe name from C# Dev Kit (if installed).
         // We explicitly call this in the LSP server start action instead of awaiting it
         // in our activation because C# Dev Kit depends on C# activation completing.
-        const csharpDevkitExtension = vscode.extensions.getExtension<CSharpDevKitExports>(csharpDevkitExtensionId);
+        const csharpDevkitExtension = getCSharpDevKit();
         if (csharpDevkitExtension) {
             _wasActivatedWithCSharpDevkit = true;
 

src/main.ts

@@ -89,7 +89,7 @@ export async function activate(
 
     requiredPackageIds.push('Razor');
 
-    const csharpDevkitExtension = vscode.extensions.getExtension(csharpDevkitExtensionId);
+    const csharpDevkitExtension = getCSharpDevKit();
     const useOmnisharpServer = !csharpDevkitExtension && commonOptions.useOmnisharpServer;
     if (useOmnisharpServer) {
         requiredPackageIds.push('OmniSharp');

src/shared/options.ts

@@ -72,6 +72,7 @@ export interface LanguageServerOptions {
     readonly logLevel: string;
     readonly documentSelector: DocumentSelector;
     readonly extensionsPaths: string[] | null;
+    readonly loadProjectsWithCSharpExtension: boolean;
 }
 
 export interface RazorOptions {
@@ -377,6 +378,9 @@ class LanguageServerOptionsImpl implements LanguageServerOptions {
     public get extensionsPaths() {
         return readOption<string[] | null>('dotnet.server.extensionPaths', null);
     }
+    public get loadProjectsWithCSharpExtension() {
+        return readOption<boolean>('dotnet.loadProjectsWithCSharpExtension', false);
+    }
 }
 
 class RazorOptionsImpl implements RazorOptions {
@@ -469,4 +473,5 @@ export const OmnisharpOptionsThatTriggerReload: ReadonlyArray<keyof OmnisharpSer
 export const LanguageServerOptionsThatTriggerReload: ReadonlyArray<keyof LanguageServerOptions> = [
     'logLevel',
     'documentSelector',
+    'loadProjectsWithCSharpExtension',
 ];

src/utils/getCSharpDevKit.ts

@@ -5,10 +5,16 @@
 
 import * as vscode from 'vscode';
 import { CSharpDevKitExports } from '../csharpDevKitExports';
+import { languageServerOptions } from '../shared/options';
 
 export const csharpDevkitExtensionId = 'ms-dotnettools.csdevkit';
 export const csharpDevkitIntelliCodeExtensionId = 'ms-dotnettools.vscodeintellicode-csharp';
 
 export function getCSharpDevKit(): vscode.Extension<CSharpDevKitExports> | undefined {
+    // Devkit is explicitly disabled via the option - we should ignore it even if it exists.
+    if (languageServerOptions.loadProjectsWithCSharpExtension) {
+        return undefined;
+    }
+
     return vscode.extensions.getExtension<CSharpDevKitExports>(csharpDevkitExtensionId);
 }