[Xamarin.Android.Tools.AndroidSdk] Preview Build-Tools are Last

Makefile

@@ -1,5 +1,5 @@
 CONFIGURATION   := Debug
-NUNIT_CONSOLE   := packages/NUnit.ConsoleRunner.3.9.0/tools/nunit3-console.exe
+NUNIT_CONSOLE   := packages/nunit.consolerunner/3.9.0/tools/nunit3-console.exe
 OS              := $(shell uname)
 RUNTIME         := mono --debug=casts
 V               ?= 0
@@ -23,7 +23,7 @@ define RUN_NUNIT_TEST
 	$(RUNTIME) \
 		$(NUNIT_CONSOLE) $(NUNIT_EXTRA) $(1) \
 		$(if $(RUN),-run:$(RUN)) \
-		--result="TestResult-$(basename $(notdir $(1))).xml;format=nunit2" \
+		--result="TestResult-$(basename $(notdir $(1))).xml" \
 		-output=bin/Test$(CONFIGURATION)/TestOutput-$(basename $(notdir $(1))).txt \
 	|| true ; \
 	if [ -f "bin/Test$(CONFIGURATION)/TestOutput-$(basename $(notdir $(1))).txt" ] ; then \

NuGet.config

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+    <!-- ensure only the sources defined below are used -->
+    <add key="dotnet-eng" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-eng/nuget/v3/index.json" protocolVersion="3" />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
+    <add key="dotnet internal feed" value="https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json" protocolVersion="3" />
+
+     <!-- This is needed (currently) for the Xamarin.Android.Deploy.Installer dependency, getting the installer -->
+     <!-- Android binary, to support delta APK install -->
+     <add key="xamarin.android util" value="https://pkgs.dev.azure.com/xamarin/public/_packaging/Xamarin.Android/nuget/v3/index.json" />
+  </packageSources>
+  <config>
+    <add key="globalPackagesFolder" value="packages" />
+  </config>
+</configuration>

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

@@ -45,17 +45,17 @@ public IEnumerable<string> GetBuildToolsPaths ()
 		{
 			var buildTools  = Path.Combine (AndroidSdkPath, "build-tools");
 			if (Directory.Exists (buildTools)) {
+				var sorted = SortedSubdirectoriesByVersion (buildTools);
+
+				foreach (var d in sorted)
+					yield return d;
+
 				var preview = Directory.EnumerateDirectories (buildTools)
 					.Where(x => TryParseVersion (Path.GetFileName (x)) == null)
 					.Select(x => x);
 
 				foreach (var d in preview)
 					yield return d;
-
-				var sorted = SortedSubdirectoriesByVersion (buildTools);
-
-				foreach (var d in sorted)
-					yield return d;
 			}
 			var ptPath  = Path.Combine (AndroidSdkPath, "platform-tools");
 			if (Directory.Exists (ptPath))

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

@@ -448,5 +448,30 @@ string UnixConfigPath {
 				return Path.Combine (UnixConfigDirOverridePath, "monodroid-config.xml");
 			}
 		}
+
+		[Test]
+		public void GetBuildToolsPaths_StableVersionsFirst ()
+		{
+			CreateSdks (out string root, out string jdk, out string ndk, out string sdk);
+			CreateFauxAndroidSdkDirectory (sdk, "27.0.0-rc4");
+
+			var logs    = new StringWriter ();
+			Action<TraceLevel, string> logger = (level, message) => {
+				logs.WriteLine ($"[{level}] {message}");
+			};
+
+			try {
+				var info    = new AndroidSdkInfo (logger, androidSdkPath: sdk, androidNdkPath: ndk, javaSdkPath: jdk);
+
+				var buildToolsPaths = info.GetBuildToolsPaths ().ToList ();
+				Assert.AreEqual (3, buildToolsPaths.Count);
+				Assert.AreEqual (Path.Combine (sdk, "build-tools", "26.0.0"),       buildToolsPaths [0]);
+				Assert.AreEqual (Path.Combine (sdk, "build-tools", "27.0.0-rc4"),   buildToolsPaths [1]);
+				Assert.AreEqual (Path.Combine (sdk, "platform-tools"),              buildToolsPaths [2]);
+			}
+			finally {
+				Directory.Delete (root, recursive: true);
+			}
+		}
 	}
 }