Use simctl --json-output flag to avoid stdout pollution (#170)

* Initial plan

* fix: route ConsoleLogger Info/Warning/Debug to stderr instead of stdout

LogInfo, LogWarning, and LogDebug in ConsoleLogger now use
Console.Error.WriteLine (stderr) instead of Console.WriteLine (stdout).
This prevents log messages from polluting structured output (e.g. JSON)
for consumers that capture stdout.

Fixes #2

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Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>

* final progress update

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Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>

* remove accidentally committed .nuget/nuget.exe and add .nuget/ to .gitignore

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Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>

* revert ConsoleLogger stderr changes; add SimCtl.RunToFile for file-based output

Per reviewer feedback: writing to stderr breaks MSBuild tasks. Instead,
add SimCtl.RunToFile() so consumers can capture structured output (JSON)
to a file, isolating it from any stdout noise.

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Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>

* address code review: use IsNullOrWhiteSpace and handle file write exceptions

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Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>

* remove .nuget/nuget.exe and add .nuget/ to .gitignore

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Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>

* Use simctl --json-output flag instead of capturing stdout

Per reviewer feedback, use xcrun simctl's native --json-output=<file>
flag to write structured JSON output directly to a temp file, instead
of capturing stdout and writing it ourselves.

- Revert RunToFile/RunCore approach back to original Run() method
- Add RunJson() that passes --json --json-output=<tempPath> to simctl
  and reads the result from the temp file
- Update SimulatorService, RuntimeService, and tests to use RunJson()

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix test runner: add Microsoft.NET.Test.Sdk, downgrade NUnit3TestAdapter to 4.6.0

NUnit3TestAdapter 5.0.0 pulled in Microsoft.Testing.Platform which brought
a broken transitive dependency chain (ApplicationInsights, Telemetry DLLs
not copied to output). Downgrade to 4.6.0 to avoid the Testing Platform
migration issues.

Add Microsoft.NET.Test.Sdk (implicitly referenced by .NET SDK) and
CopyLocalLockFileAssemblies to ensure all test dependencies are resolved
at runtime. Remove NUnit.ConsoleRunner (unused with dotnet test).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address review: use GetTempFileName and check Run() result in RunJson

- Use Path.GetTempFileName() instead of GetRandomFileName() to
  atomically reserve the temp file path (avoids race condition).
- Check Run() return value before reading the file, so simctl
  failures surface the correct error instead of a misleading
  'no JSON output file' message.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix TestHelper.ProjectDir to find source tests dir, not build output

The walk-up logic stopped at artifacts/bin/tests/ (first dir named
'tests') instead of the source tests/ directory. Fix by requiring
tests.csproj to exist as a sentinel, disambiguating the source
directory from the Arcade SDK output layout.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix CI: suppress NETSDK1023/NU1504 for Microsoft.NET.Test.Sdk

The explicit PackageReference is needed for testhost.runtimeconfig.json,
but .NET SDK 10.0+ implicitly references it causing duplicate errors.
Suppress NETSDK1023 and NU1504 in the test project.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Restore NUnit3TestAdapter to 5.0.0; no downgrade needed with explicit Microsoft.NET.Test.Sdk

Tested: build succeeds and 118/119 tests pass (1 skipped) with NUnit3TestAdapter
5.0.0 + Microsoft.NET.Test.Sdk 17.12.0.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>
Co-authored-by: Rui Marinho <me@ruimarinho.net>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

.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>