Use simctl --json-output flag to avoid stdout pollution

.gitignore

@@ -7,3 +7,4 @@ obj
 *.nupkg
 artifacts/
 .packages/
+.nuget/

Xamarin.MacDev/RuntimeService.cs

@@ -31,7 +31,7 @@ public RuntimeService (ICustomLogger log)
 	/// </summary>
 	public List<SimulatorRuntimeInfo> List (bool availableOnly = false)
 	{
-		var json = simctl.Run ("list", "runtimes", "--json");
+		var json = simctl.RunJson ("list", "runtimes");
 		if (json is null)
 			return new List<SimulatorRuntimeInfo> ();
 

Xamarin.MacDev/SimCtl.cs

@@ -57,4 +57,40 @@ public SimCtl (ICustomLogger log)
 			return null;
 		}
 	}
+
+	/// <summary>
+	/// Runs <c>xcrun simctl {args}</c> with <c>--json --json-output=&lt;file&gt;</c>
+	/// so that structured JSON output is written to a temp file instead of stdout.
+	/// Returns the file contents, or null on failure.
+	/// This is intended for <c>simctl list</c> subcommands that support <c>--json-output</c>.
+	/// </summary>
+	public string? RunJson (params string [] args)
+	{
+		var tempPath = Path.GetTempFileName ();
+		try {
+			var jsonArgs = new string [args.Length + 2];
+			Array.Copy (args, jsonArgs, args.Length);
+			jsonArgs [args.Length] = "--json";
+			jsonArgs [args.Length + 1] = "--json-output=" + tempPath;
+
+			var result = Run (jsonArgs);
+			if (result is null)
+				return null;
+
+			if (!File.Exists (tempPath)) {
+				log.LogInfo ("simctl did not produce JSON output file at '{0}'.", tempPath);
+				return null;
+			}
+
+			var content = File.ReadAllText (tempPath);
+			if (string.IsNullOrWhiteSpace (content)) {
+				log.LogInfo ("simctl produced an empty JSON output file at '{0}'.", tempPath);
+				return null;
+			}
+
+			return content;
+		} finally {
+			try { if (File.Exists (tempPath)) File.Delete (tempPath); } catch { }
+		}
+	}
 }

Xamarin.MacDev/SimulatorService.cs

@@ -31,7 +31,7 @@ public SimulatorService (ICustomLogger log)
 	/// </summary>
 	public List<SimulatorDeviceInfo> List (bool availableOnly = false)
 	{
-		var json = simctl.Run ("list", "devices", "--json");
+		var json = simctl.RunJson ("list", "devices");
 		if (json is null)
 			return new List<SimulatorDeviceInfo> ();
 

eng/Versions.props

@@ -19,5 +19,6 @@
     <NUnitAnalyzersVersion>4.3.0</NUnitAnalyzersVersion>
     <NUnitConsoleRunnerVersion>3.18.1</NUnitConsoleRunnerVersion>
     <NUnit3TestAdapterVersion>5.0.0</NUnit3TestAdapterVersion>
+    <MicrosoftNETTestSdkVersion>17.12.0</MicrosoftNETTestSdkVersion>
   </PropertyGroup>
 </Project>

tests/SimctlOutputParserTests.cs

@@ -379,7 +379,7 @@ public void LiveSimctlList_ParsesWithoutExceptions ()
 		// with no exceptions logged — per rolfbjarne review feedback
 		var logger = new TestLogger ();
 		var simctl = new SimCtl (logger);
-		var json = simctl.Run ("list", "--json");
+		var json = simctl.RunJson ("list");
 		Assert.That (json, Is.Not.Null, "simctl list --json should return output");
 
 		var devices = SimctlOutputParser.ParseDevices (json, logger);

tests/tests.csproj

@@ -8,14 +8,18 @@
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>
     <IsShipping>false</IsShipping>
+    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+    <!-- Explicit Microsoft.NET.Test.Sdk is needed for testhost.runtimeconfig.json;
+         suppress NETSDK1023 on SDKs that implicitly reference it. -->
+    <NoWarn>$(NoWarn);NETSDK1023;NU1504</NoWarn>
   </PropertyGroup>
   <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(MicrosoftNETTestSdkVersion)" />
     <PackageReference Include="NUnit" Version="$(NUnitVersion)" />
     <PackageReference Include="NUnit.Analyzers" Version="$(NUnitAnalyzersVersion)">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="NUnit.ConsoleRunner" Version="$(NUnitConsoleRunnerVersion)" />
     <PackageReference Include="NUnit3TestAdapter" Version="$(NUnit3TestAdapterVersion)" />
   </ItemGroup>
   <ItemGroup>