[tests] Unit tests for finding NDK location based on $PATH (#40)

Commit 511d580 didn't provide unit tests to ensure that the
Android NDK could be found based on probing `$PATH` for `ndk-stack`.

Update `AndroidSdkInfoTests` to ensure that the NDK to be found based
on `$PATH`, as well as the Android SDK and JDK.

Additionally, JDK-via-$PATH detection hit a few hiccups:

 1. `JdkInfo.GetKnownSystemJdkInfos()` would always check
    `/usr/libexec/java_home` before `$PATH`, meaning it wasn't
    possible to test JDK-via-$PATH!

    Alter the ordering of `JdkInfo.GetKnownSystemJdkInfos()` so that
    we probe `$PATH` before hitting `/usr/libexec/java_home`.

 2. `JdkInfo` requires that the `java.home` property be printed, which
    `JdkInfoTests.CreateFauxJdk()` didn't print, which caused the fake
    JDK to be skipped.  Fix `JdkInfoTests.CreateFauxJdk()` so that the
    resulting `java` is acceptable by `JdkInfo`.

Additionally, for greater `monodroid-config.xml` sanity (see also
a4aad18 and b42c217), instead of backing up the *global*
`monodroid-config.xml` file, instead allow the location of
`monodroid-config.xml` to be overridden by the unit tests by setting a
value accessible by `AppDomain.GetData()`, a'la a4aad18.

Finally, allow the `logger` parameter to
`JdkInfo.GetKnownSystemJdkInfos()` to be optional; if not provided, it
will print to the Console.

Author: jonpryor

src/Xamarin.Android.Tools.AndroidSdk/AndroidSdkInfo.cs

@@ -144,7 +144,7 @@ public static void SetPreferredAndroidNdkPath (string path, Action<TraceLevel, s
 			sdk.SetPreferredAndroidNdkPath(path);
 		}
 
-		static void DefaultConsoleLogger (TraceLevel level, string message)
+		internal static void DefaultConsoleLogger (TraceLevel level, string message)
 		{
 			switch (level) {
 			case TraceLevel.Error:

src/Xamarin.Android.Tools.AndroidSdk/JdkInfo.cs

@@ -207,14 +207,16 @@ static Dictionary<string, List<string>> GetJavaProperties (string java)
 			return props;
 		}
 
-		public static IEnumerable<JdkInfo> GetKnownSystemJdkInfos (Action<TraceLevel, string> logger)
+		public static IEnumerable<JdkInfo> GetKnownSystemJdkInfos (Action<TraceLevel, string> logger = null)
 		{
+			logger  = logger ?? AndroidSdkInfo.DefaultConsoleLogger;
+
 			return GetWindowsJdks (logger)
 				.Concat (GetConfiguredJdks (logger))
 				.Concat (GetMacOSMicrosoftJdks (logger))
 				.Concat (GetJavaHomeEnvironmentJdks (logger))
-				.Concat (GetLibexecJdks (logger))
 				.Concat (GetPathEnvironmentJdks (logger))
+				.Concat (GetLibexecJdks (logger))
 				.Concat (GetJavaAlternativesJdks (logger))
 				;
 		}

src/Xamarin.Android.Tools.AndroidSdk/Sdks/AndroidSdkUnix.cs

@@ -205,6 +205,8 @@ void AddToList (string path)
 			}
 		}
 
+		static  readonly    string  GetUnixConfigDirOverrideName            = $"UnixConfigPath directory override! {typeof (AndroidSdkInfo).AssemblyQualifiedName}";
+
 		// There's a small problem with the code below. Namely, if it runs under `sudo` the folder location
 		// returned by Environment.GetFolderPath will depend on how sudo was invoked:
 		//
@@ -231,8 +233,12 @@ void AddToList (string path)
 		//
 		private static string UnixConfigPath {
 			get {
-				var p = Environment.GetFolderPath (Environment.SpecialFolder.ApplicationData);
-				return Path.Combine (Path.Combine (p, "xbuild"), "monodroid-config.xml");
+				var p   = AppDomain.CurrentDomain.GetData (GetUnixConfigDirOverrideName)?.ToString ();
+				if (string.IsNullOrEmpty (p)) {
+					p   = Environment.GetFolderPath (Environment.SpecialFolder.ApplicationData);
+					p   = Path.Combine (p, "xbuild");
+				}
+				return Path.Combine (p, "monodroid-config.xml");
 			}
 		}
 

src/Xamarin.Android.Tools.AndroidSdk/Tests/AndroidSdkInfoTests.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using System.Text;
 using System.Xml.Linq;
 
@@ -12,6 +13,35 @@ namespace Xamarin.Android.Tools.Tests
 	[TestFixture]
 	public class AndroidSdkInfoTests
 	{
+		string      UnixConfigDirOverridePath;
+		string      PreferredJdksOverridePath;
+
+		static  readonly    string  GetMacOSMicrosoftJdkPathsOverrideName   = $"GetMacOSMicrosoftJdkPaths jdks override! {typeof (JdkInfo).AssemblyQualifiedName}";
+		static  readonly    string  GetUnixConfigDirOverrideName            = $"UnixConfigPath directory override! {typeof (AndroidSdkInfo).AssemblyQualifiedName}";
+
+		[OneTimeSetUp]
+		public void FixtureSetUp ()
+		{
+			UnixConfigDirOverridePath   = Path.GetTempFileName ();
+			File.Delete (UnixConfigDirOverridePath);
+			Directory.CreateDirectory (UnixConfigDirOverridePath);
+			AppDomain.CurrentDomain.SetData (GetUnixConfigDirOverrideName, UnixConfigDirOverridePath);
+
+			PreferredJdksOverridePath   = Path.GetTempFileName ();
+			File.Delete (PreferredJdksOverridePath);
+			Directory.CreateDirectory (PreferredJdksOverridePath);
+			AppDomain.CurrentDomain.SetData (GetMacOSMicrosoftJdkPathsOverrideName, PreferredJdksOverridePath);
+		}
+
+		[OneTimeTearDown]
+		public void FixtureTearDown ()
+		{
+			AppDomain.CurrentDomain.SetData (GetMacOSMicrosoftJdkPathsOverrideName, null);
+			AppDomain.CurrentDomain.SetData (GetUnixConfigDirOverrideName, null);
+			Directory.Delete (UnixConfigDirOverridePath, recursive: true);
+			Directory.Delete (PreferredJdksOverridePath, recursive: true);
+		}
+
 		[Test]
 		public void Constructor_NullLogger ()
 		{
@@ -22,27 +52,17 @@ public void Constructor_NullLogger ()
 		[Test]
 		public void Constructor_Paths ()
 		{
-			var root    = Path.GetTempFileName ();
-			File.Delete (root);
-			Directory.CreateDirectory (root);
-
-			var sdk     = Path.Combine (root, "sdk");
-			var jdk     = Path.Combine (root, "jdk");
-
-			Directory.CreateDirectory (sdk);
-			Directory.CreateDirectory (jdk);
-
-			CreateFauxAndroidSdkDirectory (sdk, "26.0.0");
-			CreateFauxJavaSdkDirectory (jdk, "1.8.0", out var _, out var _);
+			CreateSdks (out string root, out string jdk, out string ndk, out string sdk);
 
 			var logs    = new StringWriter ();
 			Action<TraceLevel, string> logger = (level, message) => {
 				logs.WriteLine ($"[{level}] {message}");
 			};
 
 			try {
-				var info    = new AndroidSdkInfo (logger, androidSdkPath: sdk, javaSdkPath: jdk, androidNdkPath: null);
+				var info    = new AndroidSdkInfo (logger, androidSdkPath: sdk, androidNdkPath: ndk, javaSdkPath: jdk);
 
+				Assert.AreEqual (ndk, info.AndroidNdkPath,  "AndroidNdkPath not preserved!");
 				Assert.AreEqual (sdk, info.AndroidSdkPath,  "AndroidSdkPath not preserved!");
 				Assert.AreEqual (jdk, info.JavaSdkPath,     "JavaSdkPath not preserved!");
 			}
@@ -51,8 +71,58 @@ public void Constructor_Paths ()
 			}
 		}
 
+		[Test]
+		public void Constructor_SetValuesFromPath ()
+		{
+			CreateSdks (out string root, out string jdk, out string ndk, out string sdk);
+			JdkInfoTests.CreateFauxJdk (jdk, "1.8.0");
+
+			Action<TraceLevel, string> logger = (level, message) => {
+				Console.WriteLine ($"[{level}] {message}");
+			};
+			var oldPath = Environment.GetEnvironmentVariable ("PATH");
+			try {
+				var paths   = new List<string> () {
+					Path.Combine (jdk, "bin"),
+					ndk,
+					Path.Combine (sdk, "platform-tools"),
+				};
+				paths.AddRange (oldPath.Split (new[]{Path.PathSeparator}, StringSplitOptions.RemoveEmptyEntries));
+				Environment.SetEnvironmentVariable ("PATH", string.Join (Path.PathSeparator.ToString (), paths));
+
+				var info    = new AndroidSdkInfo (logger);
+
+				Assert.AreEqual (ndk, info.AndroidNdkPath,  "AndroidNdkPath not set from $PATH!");
+				Assert.AreEqual (sdk, info.AndroidSdkPath,  "AndroidSdkPath not set from $PATH!");
+				Assert.AreEqual (jdk, info.JavaSdkPath,     "JavaSdkPath not set from $PATH!");
+			}
+			finally {
+				Environment.SetEnvironmentVariable ("PATH", oldPath);
+				Directory.Delete (root, recursive: true);
+			}
+		}
+
 		static  bool    IsWindows   => OS.IsWindows;
 
+		static void CreateSdks (out string root, out string jdk, out string ndk, out string sdk)
+		{
+			root    = Path.GetTempFileName ();
+			File.Delete (root);
+			Directory.CreateDirectory (root);
+
+			ndk     = Path.Combine (root, "ndk");
+			sdk     = Path.Combine (root, "sdk");
+			jdk     = Path.Combine (root, "jdk");
+
+			Directory.CreateDirectory (sdk);
+			Directory.CreateDirectory (ndk);
+			Directory.CreateDirectory (jdk);
+
+			CreateFauxAndroidSdkDirectory (sdk, "26.0.0");
+			CreateFauxAndroidNdkDirectory (ndk);
+			CreateFauxJavaSdkDirectory (jdk, "1.8.0", out var _, out var _);
+		}
+
 		static void CreateFauxAndroidSdkDirectory (string androidSdkDirectory, string buildToolsVersion, ApiInfo [] apiLevels = null)
 		{
 			var androidSdkToolsPath             = Path.Combine (androidSdkDirectory, "tools");
@@ -90,7 +160,28 @@ struct ApiInfo {
 			public  string      Id;
 		}
 
-		protected string CreateFauxJavaSdkDirectory (string javaPath, string javaVersion, out string javaExe, out string javacExe)
+		static void CreateFauxAndroidNdkDirectory (string androidNdkDirectory)
+		{
+			File.WriteAllText (Path.Combine (androidNdkDirectory, "ndk-stack"),     "");
+			File.WriteAllText (Path.Combine (androidNdkDirectory, "ndk-stack.cmd"), "");
+
+			string prebuiltHostName = "";
+			if (OS.IsWindows)
+				prebuiltHostName    = "windows-x86_64";
+			else if (OS.IsMac)
+				prebuiltHostName    = "darwin-x86_64";
+			else
+				prebuiltHostName    = "linux-x86_64";
+
+
+			var toolchainsDir   = Path.Combine (androidNdkDirectory, "toolchains");
+			var armToolchainDir = Path.Combine (toolchainsDir, "arm-linux-androideabi-4.9");
+			var armPrebuiltDir  = Path.Combine (armToolchainDir, "prebuilt", prebuiltHostName);
+
+			Directory.CreateDirectory (armPrebuiltDir);
+		}
+
+		static string CreateFauxJavaSdkDirectory (string javaPath, string javaVersion, out string javaExe, out string javacExe)
 		{
 			javaExe             = IsWindows ? "Java.cmd" : "java.bash";
 			javacExe            = IsWindows ? "Javac.cmd" : "javac.bash";
@@ -106,7 +197,7 @@ protected string CreateFauxJavaSdkDirectory (string javaPath, string javaVersion
 			return javaPath;
 		}
 
-		void CreateFauxJavaExe (string javaExeFullPath, string version)
+		static void CreateFauxJavaExe (string javaExeFullPath, string version)
 		{
 			var sb  = new StringBuilder ();
 			if (IsWindows) {
@@ -126,7 +217,7 @@ void CreateFauxJavaExe (string javaExeFullPath, string version)
 			}
 		}
 
-		void CreateFauxJavacExe (string javacExeFullPath, string version)
+		static void CreateFauxJavacExe (string javacExeFullPath, string version)
 		{
 			var sb  = new StringBuilder ();
 			if (IsWindows) {
@@ -142,7 +233,7 @@ void CreateFauxJavacExe (string javacExeFullPath, string version)
 			}
 		}
 
-		protected void Exec (string exe, string args)
+		static void Exec (string exe, string args)
 		{
 			var psi     = new ProcessStartInfo {
 				FileName                = exe,
@@ -168,10 +259,6 @@ public void DetectAndSetPreferredJavaSdkPathToLatest ()
 			Action<TraceLevel, string> logger = (level, message) => {
 				Console.WriteLine ($"[{level}] {message}");
 			};
-			var jdks    = Path.GetTempFileName ();
-			File.Delete (jdks);
-			Directory.CreateDirectory (jdks);
-			AppDomain.CurrentDomain.SetData ($"GetMacOSMicrosoftJdkPaths jdks override! {typeof (JdkInfo).AssemblyQualifiedName}", jdks);
 
 			var backupConfig    = UnixConfigPath + "." + Path.GetRandomFileName ();
 			try {
@@ -180,7 +267,7 @@ public void DetectAndSetPreferredJavaSdkPathToLatest ()
 					return;
 				}
 				Assert.Throws<NotSupportedException>(() => AndroidSdkInfo.DetectAndSetPreferredJavaSdkPathToLatest (logger));
-				var newJdkPath  = Path.Combine (jdks, "microsoft_dist_openjdk_1.8.999");
+				var newJdkPath  = Path.Combine (PreferredJdksOverridePath, "microsoft_dist_openjdk_1.8.999");
 				JdkInfoTests.CreateFauxJdk (newJdkPath, "1.8.999");
 
 				if (File.Exists (UnixConfigPath))
@@ -190,16 +277,14 @@ public void DetectAndSetPreferredJavaSdkPathToLatest ()
 				AssertJdkPath (newJdkPath);
 			}
 			finally {
-				AppDomain.CurrentDomain.SetData ($"GetMacOSMicrosoftJdkPaths jdks override! {typeof (JdkInfo).AssemblyQualifiedName}", null);
-				Directory.Delete (jdks, recursive: true);
 				if (File.Exists (backupConfig)) {
 					File.Delete (UnixConfigPath);
 					File.Move (backupConfig, UnixConfigPath);
 				}
 			}
 		}
 
-		static void AssertJdkPath (string expectedJdkPath)
+		void AssertJdkPath (string expectedJdkPath)
 		{
 			var config_file     = XDocument.Load (UnixConfigPath);
 			var javaEl          = config_file.Root.Element ("java-sdk");
@@ -208,10 +293,9 @@ static void AssertJdkPath (string expectedJdkPath)
 			Assert.AreEqual (expectedJdkPath, actualJdkPath);
 		}
 
-		static string UnixConfigPath {
+		string UnixConfigPath {
 			get {
-				var p = Environment.GetFolderPath (Environment.SpecialFolder.ApplicationData);
-				return Path.Combine (Path.Combine (p, "xbuild"), "monodroid-config.xml");
+				return Path.Combine (UnixConfigDirOverridePath, "monodroid-config.xml");
 			}
 		}
 	}

src/Xamarin.Android.Tools.AndroidSdk/Tests/JdkInfoTests.cs

@@ -58,8 +58,18 @@ internal static void CreateFauxJdk (string dir, string version)
 			Directory.CreateDirectory (jli);
 			Directory.CreateDirectory (jre);
 
+
+			string java =
+				$"echo Property settings:{Environment.NewLine}" +
+				$"echo \"    java.home = {dir}\"{Environment.NewLine}" +
+				$"echo \"    java.vendor = Xamarin.Android Unit Tests\"{Environment.NewLine}" +
+				$"echo \"    java.version = 100.100.100\"{Environment.NewLine}" +
+				$"echo \"    xamarin.multi-line = line the first\"{Environment.NewLine}" +
+				$"echo \"        line the second\"{Environment.NewLine}" +
+				$"echo \"        .\"{Environment.NewLine}";
+
 			CreateShellScript (Path.Combine (bin, "jar"), "");
-			CreateShellScript (Path.Combine (bin, "java"), JavaScript);
+			CreateShellScript (Path.Combine (bin, "java"), java);
 			CreateShellScript (Path.Combine (bin, "javac"), "");
 			CreateShellScript (Path.Combine (dir, "jli", "libjli.dylib"), "");
 			CreateShellScript (Path.Combine (jre, "libjvm.so"), "");
@@ -72,14 +82,6 @@ public void DeleteFauxJdk ()
 			Directory.Delete (FauxJdkDir, recursive: true);
 		}
 
-		static readonly string JavaScript =
-			$"echo Property settings:{Environment.NewLine}" +
-			$"echo \"    java.vendor = Xamarin.Android Unit Tests\"{Environment.NewLine}" +
-			$"echo \"    java.version = 100.100.100\"{Environment.NewLine}" +
-			$"echo \"    xamarin.multi-line = line the first\"{Environment.NewLine}" +
-			$"echo \"        line the second\"{Environment.NewLine}" +
-			$"echo \"        .\"{Environment.NewLine}";
-
 		static void CreateShellScript (string path, string contents)
 		{
 			if (OS.IsWindows)
@@ -142,11 +144,14 @@ public void JavaSettingsProperties ()
 		{
 			var jdk     = new JdkInfo (FauxJdkDir);
 
-			Assert.AreEqual (3, jdk.JavaSettingsPropertyKeys.Count ());
+			Assert.AreEqual (4, jdk.JavaSettingsPropertyKeys.Count ());
 
 			Assert.IsFalse(jdk.GetJavaSettingsPropertyValue ("does-not-exist", out var _));
 			Assert.IsFalse(jdk.GetJavaSettingsPropertyValues ("does-not-exist", out var _));
 
+			Assert.IsTrue (jdk.GetJavaSettingsPropertyValue ("java.home", out var home));
+			Assert.AreEqual (FauxJdkDir, home);
+
 			Assert.IsTrue (jdk.GetJavaSettingsPropertyValue ("java.version", out var version));
 			Assert.AreEqual ("100.100.100", version);