Introducing the concept of neutral packages. Added the new "installed" folder to gitignore for dev workflows.

Author: AbhitejJohn

.gitignore

@@ -15,6 +15,7 @@ out
 .razorDevKit/
 .razorExtension/
 .vscode-test/
+.roslynCopilot/
 msbuild/signing/signJs/*.log
 msbuild/signing/signVsix/*.log
 dist/

package.json

@@ -424,18 +424,14 @@
     },
     {
       "id": "RoslynCopilot",
-      "description": "Language server for Roslyn Copilot integration (Windows)",
+      "description": "Language server for Roslyn Copilot integration",
       "url": "https://roslyn.blob.core.windows.net/releases/Microsoft.VisualStudio.Copilot.Roslyn.LanguageServer-17.0.460-alpha-g8013717149",
       "installPath": ".roslynCopilot",
       "platforms": [
-        "win32",
-        "linux",
-        "linux-musl",
-        "darwin"
+        "neutral"
       ],
       "architectures": [
-        "x86_64",
-        "arm64"
+        "neutral"
       ],
       "installTestPath": "./.roslynCopilot/Microsoft.VisualStudio.Copilot.Roslyn.LanguageServer.dll",
       "integrity": "9944EBD6EE06BD595BCADD3057CD9BEF4105C3A3952DAE03E54F3114E2E6661F"

src/lsptoolshost/server/roslynLanguageServer.ts

@@ -8,8 +8,6 @@ import * as path from 'path';
 import * as cp from 'child_process';
 import * as uuid from 'uuid';
 import * as net from 'net';
-import * as fs from 'fs';
-import * as util from '../../common';
 import {
     LanguageClientOptions,
     MessageTransports,
@@ -687,7 +685,7 @@ export class RoslynLanguageServer {
             const csharpDevKitArgs = this.getCSharpDevKitExportArgs(additionalExtensionPaths);
             args = args.concat(csharpDevKitArgs);
 
-            await this.setupDevKitEnvironment(dotnetInfo.env, csharpDevkitExtension, additionalExtensionPaths, channel);
+            await this.setupDevKitEnvironment(dotnetInfo.env, csharpDevkitExtension, additionalExtensionPaths);
         } else {
             // C# Dev Kit is not installed - continue C#-only activation.
             channel.info('Activating C# standalone...');
@@ -1066,8 +1064,7 @@ export class RoslynLanguageServer {
     private static async setupDevKitEnvironment(
         env: NodeJS.ProcessEnv,
         csharpDevkitExtension: vscode.Extension<CSharpDevKitExports>,
-        additionalExtensionPaths: string[],
-        channel: vscode.LogOutputChannel
+        additionalExtensionPaths: string[]
     ): Promise<void> {
         const exports: CSharpDevKitExports = await csharpDevkitExtension.activate();
 

src/packageManager/packageFilterer.ts

@@ -7,6 +7,8 @@ import { PlatformInformation } from '../shared/platform';
 import * as util from '../common';
 import { AbsolutePathPackage } from './absolutePathPackage';
 
+const NEUTRAL = 'neutral';
+
 export async function getNotInstalledPackagesForPlatform(
     packages: AbsolutePathPackage[],
     platformInfo: PlatformInformation
@@ -17,7 +19,11 @@ export async function getNotInstalledPackagesForPlatform(
 
 export function filterPlatformPackages(packages: AbsolutePathPackage[], platformInfo: PlatformInformation) {
     return packages.filter(
-        (pkg) => pkg.architectures.includes(platformInfo.architecture) && pkg.platforms.includes(platformInfo.platform)
+        (pkg) =>
+            // Match architecture, packages declared neutral are included as well.
+            (pkg.architectures.includes(NEUTRAL) || pkg.architectures.includes(platformInfo.architecture)) &&
+            // Match platform, packages declared neutral are included as well.
+            (pkg.platforms.includes(NEUTRAL) || pkg.platforms.includes(platformInfo.platform))
     );
 }
 

test/omnisharp/omnisharpUnitTests/packages/packageFilterer.test.ts

@@ -55,6 +55,24 @@ describe(`${getNotInstalledPackagesForPlatform.name}`, () => {
             architectures: ['architecture2'],
             installPath: 'path3',
         },
+        {
+            description: 'neutral platform and architecture uninstalled package',
+            platforms: ['neutral'],
+            architectures: ['neutral'],
+            installPath: 'path6',
+        },
+        {
+            description: 'neutral platform but specific architecture package',
+            platforms: ['neutral'],
+            architectures: ['architecture1'],
+            installPath: 'path7',
+        },
+        {
+            description: 'specific platform but neutral architecture package',
+            platforms: ['linux'],
+            architectures: ['neutral'],
+            installPath: 'path8',
+        },
     ];
 
     beforeEach(async () => {
@@ -79,18 +97,46 @@ describe(`${getNotInstalledPackagesForPlatform.name}`, () => {
     test('Filters the packages based on Platform Information', async () => {
         const platformInfo = new PlatformInformation('win32', 'architecture2');
         const filteredPackages = await getNotInstalledPackagesForPlatform(absolutePathPackages, platformInfo);
-        expect(filteredPackages.length).toEqual(1);
+        expect(filteredPackages.length).toEqual(2);
         expect(filteredPackages[0].description).toEqual('win32-Architecture2 uninstalled package');
         expect(filteredPackages[0].platforms[0]).toEqual('win32');
         expect(filteredPackages[0].architectures[0]).toEqual('architecture2');
+
+        expect(filteredPackages[1].description).toEqual('neutral platform and architecture uninstalled package');
+        expect(filteredPackages[1].platforms[0]).toEqual('neutral');
+        expect(filteredPackages[1].architectures[0]).toEqual('neutral');
     });
 
     test('Returns only the packages where install.Lock is not present', async () => {
         const platformInfo = new PlatformInformation('linux', 'architecture1');
         const filteredPackages = await getNotInstalledPackagesForPlatform(absolutePathPackages, platformInfo);
+        // Should include linux-Architecture1 package + neutral package (both uninstalled)
+        expect(filteredPackages.length).toEqual(4);
+
+        const descriptions = filteredPackages.map((pkg) => pkg.description);
+        expect(descriptions).toContain('linux-Architecture1 uninstalled package');
+        expect(descriptions).toContain('neutral platform and architecture uninstalled package');
+        expect(descriptions).toContain('neutral platform but specific architecture package');
+        expect(descriptions).toContain('specific platform but neutral architecture package');
+    });
+
+    test('Returns only neutral packages when no platform-specific packages match', async () => {
+        const platformInfo = new PlatformInformation('darwin', 'arm64'); // Non-existent platform/arch combo
+        const filteredPackages = await getNotInstalledPackagesForPlatform(absolutePathPackages, platformInfo);
+
+        // Should only include neutral package (uninstalled one)
+        expect(filteredPackages.length).toEqual(1);
+        expect(filteredPackages[0].description).toEqual('neutral platform and architecture uninstalled package');
+        expect(filteredPackages[0].platforms[0]).toEqual('neutral');
+        expect(filteredPackages[0].architectures[0]).toEqual('neutral');
+    });
+
+    test('Filters out installed neutral packages', async () => {
+        const platformInfo = new PlatformInformation('darwin', 'arm64'); // Only neutral packages should match
+        const filteredPackages = await getNotInstalledPackagesForPlatform(absolutePathPackages, platformInfo);
+
+        // Should only return uninstalled neutral package, not the installed one
         expect(filteredPackages.length).toEqual(1);
-        expect(filteredPackages[0].description).toEqual('linux-Architecture1 uninstalled package');
-        expect(filteredPackages[0].platforms[0]).toEqual('linux');
-        expect(filteredPackages[0].architectures[0]).toEqual('architecture1');
+        expect(filteredPackages[0].description).toEqual('neutral platform and architecture uninstalled package');
     });
 });