Address Copilot review round 3: remove null-forgiving, validate port range

- Replace null! with null in tests (no nullable context in test project)
- Replace socketSpec! with property pattern (is not { Length: > 0 }) for null flow
- Add port range validation (1-65535) in ReversePortAsync and RemoveReversePortAsync

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

Author: rmarinho

src/Xamarin.Android.Tools.AndroidSdk/Runners/AdbPortSpec.cs

@@ -27,11 +27,9 @@ public record AdbPortSpec (AdbProtocol Protocol, int Port)
 	/// </summary>
 	public static AdbPortSpec? TryParse (string? socketSpec)
 	{
-		if (string.IsNullOrWhiteSpace (socketSpec))
+		if (socketSpec is not { Length: > 0 } value || string.IsNullOrWhiteSpace (value))
 			return null;
 
-		// socketSpec is guaranteed non-null after IsNullOrWhiteSpace check
-		var value = socketSpec!;
 		var colonIndex = value.IndexOf (':');
 		if (colonIndex <= 0 || colonIndex >= value.Length - 1)
 			return null;

src/Xamarin.Android.Tools.AndroidSdk/Runners/AdbRunner.cs

@@ -259,6 +259,10 @@ public virtual async Task ReversePortAsync (string serial, AdbPortSpec remote, A
 			throw new ArgumentNullException (nameof (remote));
 		if (local is null)
 			throw new ArgumentNullException (nameof (local));
+		if (remote.Port <= 0 || remote.Port > 65535)
+			throw new ArgumentOutOfRangeException (nameof (remote), remote.Port, "Port must be between 1 and 65535.");
+		if (local.Port <= 0 || local.Port > 65535)
+			throw new ArgumentOutOfRangeException (nameof (local), local.Port, "Port must be between 1 and 65535.");
 
 		var psi = ProcessUtils.CreateProcessStartInfo (adbPath, "-s", serial, "reverse", remote.ToSocketSpec (), local.ToSocketSpec ());
 		using var stderr = new StringWriter ();
@@ -279,6 +283,8 @@ public virtual async Task RemoveReversePortAsync (string serial, AdbPortSpec rem
 			throw new ArgumentException ("Serial must not be empty.", nameof (serial));
 		if (remote is null)
 			throw new ArgumentNullException (nameof (remote));
+		if (remote.Port <= 0 || remote.Port > 65535)
+			throw new ArgumentOutOfRangeException (nameof (remote), remote.Port, "Port must be between 1 and 65535.");
 
 		var psi = ProcessUtils.CreateProcessStartInfo (adbPath, "-s", serial, "reverse", "--remove", remote.ToSocketSpec ());
 		using var stderr = new StringWriter ();

tests/Xamarin.Android.Tools.AndroidSdk-Tests/AdbRunnerTests.cs

@@ -1021,15 +1021,15 @@ public void ReversePortAsync_NullRemote_ThrowsArgumentNull ()
 	{
 		var runner = new AdbRunner ("/fake/sdk/platform-tools/adb");
 		Assert.ThrowsAsync<System.ArgumentNullException> (
-			async () => await runner.ReversePortAsync ("emulator-5554", (AdbPortSpec) null!, new AdbPortSpec (AdbProtocol.Tcp, 5000)));
+			async () => await runner.ReversePortAsync ("emulator-5554", (AdbPortSpec) null, new AdbPortSpec (AdbProtocol.Tcp, 5000)));
 	}
 
 	[Test]
 	public void ReversePortAsync_NullLocal_ThrowsArgumentNull ()
 	{
 		var runner = new AdbRunner ("/fake/sdk/platform-tools/adb");
 		Assert.ThrowsAsync<System.ArgumentNullException> (
-			async () => await runner.ReversePortAsync ("emulator-5554", new AdbPortSpec (AdbProtocol.Tcp, 5000), (AdbPortSpec) null!));
+			async () => await runner.ReversePortAsync ("emulator-5554", new AdbPortSpec (AdbProtocol.Tcp, 5000), (AdbPortSpec) null));
 	}
 
 	// --- RemoveReversePortAsync parameter validation tests ---
@@ -1047,7 +1047,7 @@ public void RemoveReversePortAsync_NullRemote_ThrowsArgumentNull ()
 	{
 		var runner = new AdbRunner ("/fake/sdk/platform-tools/adb");
 		Assert.ThrowsAsync<System.ArgumentNullException> (
-			async () => await runner.RemoveReversePortAsync ("emulator-5554", (AdbPortSpec) null!));
+			async () => await runner.RemoveReversePortAsync ("emulator-5554", (AdbPortSpec) null));
 	}
 
 	// --- RemoveAllReversePortsAsync parameter validation tests ---