Fix sort ordering for ndk-bundle, add macOS support (#91)

Fixes: #92
Context: #90 (comment)
The PR builds for #90 encountered an "unrelated test failure" in `AndroidSdkInfoTests.Ndk_PathInSdk()` on Windows, because Windows
is non-deterministic: the test asserts that given an Android SDK
directory `androidSdk` which contains the file
`{androidSdk}\ndk-bundle\ndk-stack.cmd`, then this:
var info = new AndroidSdkInfo (logger: null, androidSdkPath: androidSdk);
will have `info.AndroidNdkPath`==`{androidSdk}\ndk-bundle`.
Instead, this test would occasionally fail on CI:
Ndk_PathInSdk
AndroidNdkPath not found inside sdk!
Expected string length 71 but was 53. Strings differ at index 3.
Expected: "C:\Users\VssAdministrator\AppData\Local\Temp\tmpAE78.tmp\sdk\..."
But was: "C:\Program Files (x86)\Android\android-sdk\ndk-bundle"
Here, the "preferred"/system-wide NDK is being chosen over the
`{androidSdk}\ndk-bundle` directory that the unit test created.
The wrong directory was chosen for two reasons: 1. `AndroidSdkBase.Initialize()` would use `PreferedAndroidNdkPath`
when `androidNdkPath` was null, *first*, before we checked
`{androidSdk}\ndk-bundle`.
2. If `PreferedAndroidNdkPath` happened to be null, then
`AndroidSdkBase.Initialize()` would try to use
`AllAndroidNdks.FirstOrDefault()` as a default value, also before
checking `{androidSdk}\ndk-bundle`. The problem here is that the
`AllAndrdoidNdks` property uses [`Enumerable.Distinct()`][0], which
returns an *unordered* list of directories.
That the test ever worked at all is a minor miracle.
Additionally, the support for `{androidSdk}\ndk-bundle` was Windows-
specific; it didn't run on macOS.
Update `AndroidSdkInfo` so that `{androidSdk}/ndk-bundle` is supported
on macOS, and that `{androidSdk}/ndk-bundle` is *preferred* when the
`androidNdkPath` parameter is `null`, *before* checking any other
plausible default locations.
This allows the `AndroidSdkInfoTests.Ndk_PathInSdk()` test to run
everywhere, and work reliably.
[0]: https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.distinct?view=netcore-3.1

Author: jonathanpeppers

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

@@ -10,22 +10,21 @@ namespace Xamarin.Android.Tools
 abstractclassAndroidSdkBase
 {
 string[]?allAndroidSdks;
-string[]?allAndroidNdks;
 
 publicstring[]AllAndroidSdks{
 get{
-if(allAndroidSdks==null)
-allAndroidSdks=GetAllAvailableAndroidSdks().Distinct().ToArray();
+if(allAndroidSdks==null){
+vardirs=newList<string?>();
+dirs.Add(AndroidSdkPath);
+dirs.AddRange(GetAllAvailableAndroidSdks());
+allAndroidSdks=dirs.Where(d =>ValidateAndroidSdkLocation(d))
+.Select(d =>d!)
+.Distinct()
+.ToArray();
+}
 returnallAndroidSdks;
 }
 }
-publicstring[]AllAndroidNdks{
-get{
-if(allAndroidNdks==null)
-allAndroidNdks=GetAllAvailableAndroidNdks().Distinct().ToArray();
-returnallAndroidNdks;
-}
-}
 
 publicreadonlyAction<TraceLevel,string>Logger;
 
@@ -57,13 +56,10 @@ public AndroidSdkBase (Action<TraceLevel, string> logger)
 
 publicvirtualvoidInitialize(string?androidSdkPath=null,string?androidNdkPath=null,string?javaSdkPath=null)
 {
-androidSdkPath=androidSdkPath??PreferedAndroidSdkPath;
-androidNdkPath=androidNdkPath??PreferedAndroidNdkPath;
-javaSdkPath=javaSdkPath??PreferedJavaSdkPath;
+AndroidSdkPath=GetValidPath(ValidateAndroidSdkLocation,androidSdkPath,()=>PreferedAndroidSdkPath,()=>GetAllAvailableAndroidSdks());
+JavaSdkPath=GetValidPath(ValidateJavaSdkLocation,javaSdkPath,()=>PreferedJavaSdkPath,()=>GetJavaSdkPaths());
 
-AndroidSdkPath=ValidateAndroidSdkLocation(androidSdkPath)?androidSdkPath:AllAndroidSdks.FirstOrDefault();
-AndroidNdkPath=ValidateAndroidNdkLocation(androidNdkPath)?androidNdkPath:AllAndroidNdks.FirstOrDefault();
-JavaSdkPath=ValidateJavaSdkLocation(javaSdkPath)?javaSdkPath:GetJavaSdkPath();
+AndroidNdkPath=GetValidNdkPath(androidNdkPath);
 
 if(!string.IsNullOrEmpty(JavaSdkPath)){
 JavaBinPath=Path.Combine(JavaSdkPath,"bin");
@@ -93,11 +89,60 @@ public virtual void Initialize (string? androidSdkPath = null, string? androidNd
 NdkStack=GetExecutablePath(AndroidNdkPath,NdkStack);
 }
 
+staticstring?GetValidPath(Func<string?,bool>pathValidator,string?ctorParam,Func<string?>getPreferredPath,Func<IEnumerable<string>>getAllPaths)
+{
+if(pathValidator(ctorParam))
+returnctorParam;
+ctorParam=getPreferredPath();
+if(pathValidator(ctorParam))
+returnctorParam;
+foreach(varpathingetAllPaths()){
+if(pathValidator(path))
+returnpath;
+}
+returnnull;
+}
+
+string?GetValidNdkPath(string?ctorParam)
+{
+if(ValidateAndroidNdkLocation(ctorParam))
+returnctorParam;
+if(AndroidSdkPath!=null){
+stringbundle=Path.Combine(AndroidSdkPath,"ndk-bundle");
+if(Directory.Exists(bundle)&&ValidateAndroidNdkLocation(bundle))
+returnbundle;
+}
+ctorParam=PreferedAndroidNdkPath;
+if(ValidateAndroidNdkLocation(ctorParam))
+returnctorParam;
+foreach(varpathinGetAllAvailableAndroidNdks()){
+if(ValidateAndroidNdkLocation(path))
+returnpath;
+}
+returnnull;
+}
+
 protectedabstractIEnumerable<string>GetAllAvailableAndroidSdks();
-protectedabstractIEnumerable<string>GetAllAvailableAndroidNdks();
-protectedabstractstring?GetJavaSdkPath();
 protectedabstractstringGetShortFormPath(stringpath);
 
+protectedvirtualIEnumerable<string>GetAllAvailableAndroidNdks()
+{
+// Look in PATH
+foreach(varndkStackinProcessUtils.FindExecutablesInPath(NdkStack)){
+varndkDir=Path.GetDirectoryName(ndkStack);
+if(ndkDir==null)
+continue;
+yieldreturnndkDir;
+}
+
+// Check for the "ndk-bundle" directory inside other SDK directories
+foreach(varsdkinGetAllAvailableAndroidSdks()){
+if(sdk==AndroidSdkPath)
+continue;
+yieldreturnPath.Combine(sdk,"ndk-bundle");
+}
+}
+
 publicabstractvoidSetPreferredAndroidSdkPath(string?path);
 publicabstractvoidSetPreferredJavaSdkPath(string?path);
 publicabstractvoidSetPreferredAndroidNdkPath(string?path);
@@ -108,6 +153,12 @@ public string NdkHostPlatform {
 get{returnIsNdk64Bit?NdkHostPlatform64Bit:NdkHostPlatform32Bit;}
 }
 
+IEnumerable<string>GetJavaSdkPaths()
+{
+returnJdkInfo.GetKnownSystemJdkInfos(Logger)
+.Select(jdk =>jdk.HomePath);
+}
+
 /// <summary>
 /// Checks that a value is the location of an Android SDK.
 /// </summary>

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

@@ -98,33 +98,15 @@ protected override IEnumerable<string> GetAllAvailableAndroidSdks ()
 // Strip off "platform-tools"
 vardir=Path.GetDirectoryName(path);
 
-if(ValidateAndroidSdkLocation(dir))
-yieldreturndir;
+if(dir==null)
+continue;
+
+yieldreturndir;
 }
 
 // Check some hardcoded paths for good measure
 varmacSdkPath=Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal),"Library","Android","sdk");
-if(ValidateAndroidSdkLocation(macSdkPath))
-yieldreturnmacSdkPath;
-}
-
-protectedoverridestring?GetJavaSdkPath()
-{
-returnJdkInfo.GetKnownSystemJdkInfos(Logger).FirstOrDefault()?.HomePath;
-}
-
-protectedoverrideIEnumerable<string>GetAllAvailableAndroidNdks()
-{
-varpreferedNdkPath=PreferedAndroidNdkPath;
-if(!string.IsNullOrEmpty(preferedNdkPath))
-yieldreturnpreferedNdkPath!;
-
-// Look in PATH
-foreach(varndkStackinProcessUtils.FindExecutablesInPath(NdkStack)){
-varndkDir=Path.GetDirectoryName(ndkStack);
-if(ValidateAndroidNdkLocation(ndkDir))
-yieldreturnndkDir;
-}
+yieldreturnmacSdkPath;
 }
 
 protectedoverridestringGetShortFormPath(stringpath)

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

@@ -102,14 +102,7 @@ protected override IEnumerable<string> GetAllAvailableAndroidSdks ()
 };
 foreach(varbasePathinpaths)
 if(Directory.Exists(basePath))
-if(ValidateAndroidSdkLocation(basePath))
-yieldreturnbasePath;
-}
-
-protectedoverridestring?GetJavaSdkPath()
-{
-varjdk=JdkInfo.GetKnownSystemJdkInfos(Logger).FirstOrDefault();
-returnjdk?.HomePath;
+yieldreturnbasePath;
 }
 
 internalstaticIEnumerable<JdkInfo>GetJdkInfos(Action<TraceLevel,string>logger)
@@ -223,24 +216,13 @@ private static IEnumerable<string> GetOracleJdkPaths ()
 
 protectedoverrideIEnumerable<string>GetAllAvailableAndroidNdks()
 {
+
 varroots=new[]{RegistryEx.CurrentUser,RegistryEx.LocalMachine};
 varwow=RegistryEx.Wow64.Key32;
 varregKey=GetMDRegistryKey();
 
 Logger(TraceLevel.Info,"Looking for Android NDK...");
 
-// Check for the "ndk-bundle" directory inside the SDK directories
-stringndk;
-
-varsdks=GetAllAvailableAndroidSdks().ToList();
-if(!string.IsNullOrEmpty(AndroidSdkPath))
-sdks.Add(AndroidSdkPath!);
-
-foreach(varsdkinsdks.Distinct())
-if(Directory.Exists(ndk=Path.Combine(sdk,"ndk-bundle")))
-if(ValidateAndroidNdkLocation(ndk))
-yieldreturnndk;
-
 // Check for the key the user gave us in the VS/addin options
 foreach(varrootinroots)
 if(CheckRegistryKeyForExecutable(root,regKey,MDREG_ANDROID_NDK,wow,".",NdkStack))
@@ -265,6 +247,10 @@ protected override IEnumerable<string> GetAllAvailableAndroidNdks ()
 foreach(vardirinDirectory.GetDirectories(basePath,"android-ndk-r*"))
 if(ValidateAndroidNdkLocation(dir))
 yieldreturndir;
+
+foreach(vardirinbase.GetAllAvailableAndroidNdks()){
+yieldreturndir;
+}
 }
 
 protectedoverridestringGetShortFormPath(stringpath)

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

@@ -67,9 +67,6 @@ public void Constructor_Paths ()
 [Test]
 publicvoidNdk_PathInSdk()
 {
-if(!OS.IsWindows)
-Assert.Ignore("This only works in Windows");
-
 CreateSdks(outstringroot,outstringjdk,outstringndk,outstringsdk);
 
 varlogs=newStringWriter();
@@ -79,10 +76,11 @@ public void Ndk_PathInSdk()
 
 try
 {
+varextension=OS.IsWindows?".cmd":"";
 varndkPath=Path.Combine(sdk,"ndk-bundle");
 Directory.CreateDirectory(ndkPath);
 Directory.CreateDirectory(Path.Combine(ndkPath,"toolchains"));
-File.WriteAllText(Path.Combine(ndkPath,"ndk-stack.cmd"),"");
+File.WriteAllText(Path.Combine(ndkPath,$"ndk-stack{extension}"),"");
 
 varinfo=newAndroidSdkInfo(logger,androidSdkPath:sdk,androidNdkPath:null,javaSdkPath:jdk);