Preserve explicit AndroidSdkHome when directory doesn't exist yet

AndroidSdk.Tests/SdkTool_PreserveHome_Tests.cs

@@ -0,0 +1,141 @@
+#nullable enable
+using System;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace AndroidSdk.Tests;
+
+/// <summary>
+/// Tests that SdkTool and AndroidSdkManager preserve explicitly specified
+/// home directories even when the directory does not yet exist on disk.
+/// This is critical for the Acquire/DownloadSdk workflow where the SDK
+/// must be downloaded to a new directory.
+/// </summary>
+public class SdkTool_PreserveHome_Tests : TestsBase
+{
+	public SdkTool_PreserveHome_Tests(ITestOutputHelper outputHelper)
+		: base(outputHelper)
+	{
+	}
+
+	[Fact]
+	public void SdkManager_PreservesHome_WhenDirectoryDoesNotExist()
+	{
+		var nonExistentPath = Path.Combine(Path.GetTempPath(), "AndroidSdk.Tests", "NonExistent", Guid.NewGuid().ToString("N"));
+		Assert.False(Directory.Exists(nonExistentPath));
+
+		var mgr = new SdkManager(new SdkManagerToolOptions
+		{
+			AndroidSdkHome = new DirectoryInfo(nonExistentPath),
+			SkipVersionCheck = true
+		});
+
+		Assert.NotNull(mgr.AndroidSdkHome);
+		Assert.Equal(nonExistentPath, mgr.AndroidSdkHome!.FullName);
+	}
+
+	[Fact]
+	public void AndroidSdkManager_PreservesHome_WhenDirectoryDoesNotExist()
+	{
+		var nonExistentPath = Path.Combine(Path.GetTempPath(), "AndroidSdk.Tests", "NonExistent", Guid.NewGuid().ToString("N"));
+		Assert.False(Directory.Exists(nonExistentPath));
+
+		var mgr = new AndroidSdkManager(new DirectoryInfo(nonExistentPath));
+
+		Assert.NotNull(mgr.Home);
+		Assert.Equal(nonExistentPath, mgr.Home!.FullName);
+	}
+
+	[Fact]
+	public async Task SdkManager_DownloadSdk_DoesNotThrow_WhenDirectoryDoesNotExist()
+	{
+		var nonExistentPath = Path.Combine(Path.GetTempPath(), "AndroidSdk.Tests", "NonExistent", Guid.NewGuid().ToString("N"));
+		Assert.False(Directory.Exists(nonExistentPath));
+
+		var mgr = new SdkManager(new SdkManagerToolOptions
+		{
+			AndroidSdkHome = new DirectoryInfo(nonExistentPath),
+			SkipVersionCheck = true
+		});
+
+		// DownloadSdk should not throw DirectoryNotFoundException
+		// because AndroidSdkHome should be preserved
+		var ex = await Record.ExceptionAsync(() => mgr.DownloadSdk());
+
+		// If it throws, it should NOT be the "Directory was not specified" error
+		if (ex != null)
+		{
+			Assert.DoesNotContain("was not specified", ex.Message);
+		}
+
+		// Clean up if anything was created
+		try { if (Directory.Exists(nonExistentPath)) Directory.Delete(nonExistentPath, true); } catch { }
+	}
+
+	[Fact]
+	public void SdkManager_UsesLocatedPath_WhenDirectoryExists()
+	{
+		// When the directory exists and contains an SDK, Locate should find it
+		var existingPath = Path.Combine(Path.GetTempPath(), "AndroidSdk.Tests", "ExistingDir", Guid.NewGuid().ToString("N"));
+		Directory.CreateDirectory(existingPath);
+
+		try
+		{
+			var mgr = new SdkManager(new SdkManagerToolOptions
+			{
+				AndroidSdkHome = new DirectoryInfo(existingPath),
+				SkipVersionCheck = true
+			});
+
+			// Should still resolve to the existing path
+			Assert.NotNull(mgr.AndroidSdkHome);
+			Assert.Equal(existingPath, mgr.AndroidSdkHome!.FullName);
+		}
+		finally
+		{
+			try { Directory.Delete(existingPath, true); } catch { }
+		}
+	}
+
+	[Fact]
+	public void AndroidSdkManager_UsesLocatedPath_WhenDirectoryExists()
+	{
+		var existingPath = Path.Combine(Path.GetTempPath(), "AndroidSdk.Tests", "ExistingDir", Guid.NewGuid().ToString("N"));
+		Directory.CreateDirectory(existingPath);
+
+		try
+		{
+			var mgr = new AndroidSdkManager(new DirectoryInfo(existingPath));
+
+			Assert.NotNull(mgr.Home);
+			Assert.Equal(existingPath, mgr.Home!.FullName);
+		}
+		finally
+		{
+			try { Directory.Delete(existingPath, true); } catch { }
+		}
+	}
+
+	[Fact]
+	public void SdkManager_HomeIsNull_WhenNoPathSpecified()
+	{
+		// When no path is given and no SDK is found via env vars, 
+		// Home might be null or point to a discovered SDK — either is valid.
+		// The key invariant: if Locate() returns something, use it.
+		var mgr = new SdkManager(new SdkManagerToolOptions
+		{
+			AndroidSdkHome = null,
+			SkipVersionCheck = true
+		});
+
+		// AndroidSdkHome should be whatever Locate() found (possibly null)
+		var located = new SdkLocator().Locate()?.FirstOrDefault();
+		if (located != null)
+			Assert.Equal(located.FullName, mgr.AndroidSdkHome?.FullName);
+		else
+			Assert.Null(mgr.AndroidSdkHome);
+	}
+}

AndroidSdk/AndroidSdkManager.cs

@@ -28,7 +28,8 @@ public static IEnumerable<DirectoryInfo> FindHome(string specificHome = null, pa
 
 		public AndroidSdkManager(DirectoryInfo home = null)
 		{
-			Home = new SdkLocator().Locate(home?.FullName)?.FirstOrDefault();
+			Home = home
+				?? new SdkLocator().Locate()?.FirstOrDefault();
 
 			SdkManager = new SdkManager(new SdkManagerToolOptions { AndroidSdkHome = Home });
 			AvdManager = new AvdManager(Home);

AndroidSdk/SdkTool.cs

@@ -24,14 +24,16 @@ public SdkTool(string? androidSdkHome)
 		public SdkTool(DirectoryInfo? androidSdkHome)
 			: this(new SdkToolOptions { AndroidSdkHome = androidSdkHome })
 		{
-			AndroidSdkHome = new SdkLocator().Locate(androidSdkHome?.FullName)?.FirstOrDefault();
-			Jdks = new JdkLocator().LocateJdk()?.ToArray() ?? new JdkInfo[0];
 		}
 
 		public SdkTool(SdkToolOptions? options)
 		{
 			options ??= new();
-			AndroidSdkHome = new SdkLocator().Locate(options.AndroidSdkHome?.FullName)?.FirstOrDefault();
+			// When a path is explicitly provided, always honor it — the caller
+			// may intend to download/create the SDK there.  Only auto-discover
+			// when no path is specified.
+			AndroidSdkHome = options.AndroidSdkHome
+				?? new SdkLocator().Locate()?.FirstOrDefault();
 			Jdks = new JdkLocator().LocateJdk()?.ToArray() ?? new JdkInfo[0];
 		}