Add PATH for Arm emulation x64 on Mac

vscode-dotnet-runtime-library/src/Acquisition/DotnetCoreAcquisitionWorker.ts

@@ -476,7 +476,7 @@ To keep your .NET version up to date, please reconnect to the internet at your s
         }
 
         let dotnetPath : string = await installer.getExpectedGlobalSDKPath(installingVersion,
-            context.acquisitionContext.architecture ?? this.getDefaultInternalArchitecture(context.acquisitionContext.architecture));
+            context.acquisitionContext.architecture ?? this.getDefaultInternalArchitecture(context.acquisitionContext.architecture), false);
         const existingInstall = await this.getExistingInstall(context, installedVersions, install, dotnetPath);
         if(existingInstall)
         {
@@ -501,6 +501,10 @@ ${WinMacGlobalInstaller.InterpretExitCode(installerResult)}`), install);
 
         TelemetryUtilities.setDotnetSDKTelemetryToMatch(context.isExtensionTelemetryInitiallyEnabled, this.extensionContext, context, this.utilityContext).catch(() => {});
 
+        // in case the path does not exist, try resetting the path using an automatic path search setting
+        dotnetPath = await installer.getExpectedGlobalSDKPath(installingVersion,
+            context.acquisitionContext.architecture ?? this.getDefaultInternalArchitecture(context.acquisitionContext.architecture));
+
         try
         {
             context.installationValidator.validateDotnetInstall(install, dotnetPath, os.platform() !== 'win32');

vscode-dotnet-runtime-library/src/Acquisition/IGlobalInstaller.ts

@@ -24,7 +24,7 @@ export abstract class IGlobalInstaller {
 
     public abstract uninstallSDK(install : DotnetInstall) : Promise<string>
 
-    public abstract getExpectedGlobalSDKPath(specificSDKVersionInstalled : string, installedArch : string) : Promise<string>
+    public abstract getExpectedGlobalSDKPath(specificSDKVersionInstalled : string, installedArch : string, macPathShouldExist? : boolean) : Promise<string>
 
     public abstract getGlobalSdkVersionsInstalledOnMachine() : Promise<Array<string>>;
 

vscode-dotnet-runtime-library/src/Acquisition/LinuxGlobalInstaller.ts

@@ -35,7 +35,7 @@ export class LinuxGlobalInstaller extends IGlobalInstaller {
         return this.linuxSDKResolver.UninstallSDK(this.version);
     }
 
-    public async getExpectedGlobalSDKPath(specificSDKVersionInstalled : string, installedArch : string) : Promise<string>
+    public async getExpectedGlobalSDKPath(specificSDKVersionInstalled : string, installedArch : string, macPathShouldExist = true) : Promise<string>
     {
         await this.linuxSDKResolver.Initialize();
 

vscode-dotnet-runtime-library/src/Acquisition/WinMacGlobalInstaller.ts

@@ -319,7 +319,7 @@ Permissions: ${JSON.stringify(await this.commandRunner.execute(CommandExecutor.m
 
     // async is needed to match the interface even if we don't use await.
     // eslint-disable-next-line @typescript-eslint/require-await
-    public async getExpectedGlobalSDKPath(specificSDKVersionInstalled : string, installedArch : string) : Promise<string>
+    public async getExpectedGlobalSDKPath(specificSDKVersionInstalled : string, installedArch : string, macPathShouldExist = true) : Promise<string>
     {
         if(os.platform() === 'win32')
         {
@@ -330,7 +330,7 @@ Permissions: ${JSON.stringify(await this.commandRunner.execute(CommandExecutor.m
         }
         else if(os.platform() === 'darwin')
         {
-            return this.getMacPath();
+            return this.getMacPath(macPathShouldExist);
         }
 
         const err = new DotnetUnexpectedInstallerOSError(new EventBasedError('DotnetUnexpectedInstallerOSError',
@@ -352,11 +352,15 @@ If you were waiting for the install to succeed, please extend the timeout settin
         }
     }
 
-    private getMacPath() : string
+    private getMacPath(macPathShouldExist = true) : string
     {
-        // On an arm machine we would install to /usr/local/share/dotnet/x64/dotnet/sdk` for a 64 bit sdk
-        // but we don't currently allow customizing the install architecture so that would never happen.
-        return path.resolve(`/usr/local/share/dotnet/dotnet`);
+        const standardHostPath = path.resolve(`/usr/local/share/dotnet/dotnet`);
+        const arm64EmulationHostPath = path.resolve(`/usr/local/share/dotnet/x64/dotnet`);
+        if(!macPathShouldExist || fs.existsSync(standardHostPath) || !fs.existsSync(arm64EmulationHostPath))
+        {
+            return standardHostPath;
+        }
+        return arm64EmulationHostPath;
     }
 
     /**

vscode-dotnet-runtime-library/src/test/unit/WinMacGlobalInstaller.test.ts

@@ -228,4 +228,34 @@ ${fs.readdirSync(installerDownloadFolder).join(', ')}`);
             await installer.installSDK(install);
             mockExecutor.resetReturnValues();
         }).timeout(150000);
+
+        test('It will use arm64 emulation path IFF path does not exist and option to use it is set', async () =>
+        {
+            if(os.platform() === 'darwin')
+            {
+                const sdkVersionThatShouldNotExist = '3.0.500';
+                const standardHostPath = path.resolve(`/usr/local/share/dotnet/dotnet`);
+                const arm64EmulationHostPath = path.resolve(`/usr/local/share/dotnet/x64/dotnet`);
+
+                let cleanUpPath = false;
+                const defaultPath = await installer.getExpectedGlobalSDKPath(sdkVersionThatShouldNotExist, os.arch(), false);
+                if(!fs.existsSync(arm64EmulationHostPath))
+                {
+                    fs.mkdirSync(arm64EmulationHostPath, {recursive: true});
+                    cleanUpPath = true;
+                }
+                let shouldNotExistOptionPath = await installer.getExpectedGlobalSDKPath(sdkVersionThatShouldNotExist, os.arch());
+
+                assert.equal(defaultPath, standardHostPath, 'It uses the standard path if false is set and path dne');
+                assert.equal(shouldNotExistOptionPath, arm64EmulationHostPath, 'It uses the emu path if the std path does not exist and option is set');
+
+                if(cleanUpPath)
+                {
+                    fs.rmdirSync(arm64EmulationHostPath, {recursive: true});
+
+                    shouldNotExistOptionPath = await installer.getExpectedGlobalSDKPath(sdkVersionThatShouldNotExist, os.arch());
+                    assert.equal(shouldNotExistOptionPath, standardHostPath, 'It wont use the emu path if it does not exist');
+                }
+            }
+        }).timeout(standardTimeoutTime);
 });