AssemblyLoader should use absolute assembly path when loading assemblies (#570)

Author: suhsteve

src/csharp/Microsoft.Spark.UnitTest/AssemblyLoaderTests.cs

@@ -4,14 +4,25 @@
 
 using System;
 using System.IO;
+using System.Reflection;
+using System.Runtime.Loader;
+using Microsoft.Spark.Interop.Ipc;
 using Microsoft.Spark.Utils;
+using Moq;
 using Xunit;
 
 namespace Microsoft.Spark.UnitTest
 {
     [Collection("Spark Unit Tests")]
     public class AssemblyLoaderTests
     {
+        private readonly Mock<IJvmBridge> _mockJvm;
+
+        public AssemblyLoaderTests(SparkFixture _fixture)
+        {
+            _mockJvm = _fixture.MockJvm;
+        }
+
         [Fact]
         public void TestAssemblySearchPathResolver()
         {
@@ -45,5 +56,20 @@ public void TestAssemblySearchPathResolver()
                 AssemblySearchPathResolver.AssemblySearchPathsEnvVarName,
                 null);
         }
+
+        [Fact]
+        public void TestResolveAssemblyWithRelativePath()
+        {
+            _mockJvm.Setup(m => m.CallStaticJavaMethod(
+                "org.apache.spark.SparkFiles",
+                "getRootDirectory"))
+                .Returns(".");
+
+            AssemblyLoader.LoadFromFile = AssemblyLoadContext.Default.LoadFromAssemblyPath;
+            Assembly expectedAssembly = Assembly.GetExecutingAssembly();
+            Assembly actualAssembly = AssemblyLoader.ResolveAssembly(expectedAssembly.FullName);
+
+            Assert.Equal(expectedAssembly, actualAssembly);
+        }
     }
 }

src/csharp/Microsoft.Spark/Utils/AssemblyLoader.cs

@@ -189,12 +189,12 @@ private static bool TryLoadAssembly(string assemblyFileName, ref Assembly assemb
         {
             foreach (string searchPath in s_searchPaths.Value)
             {
-                string assemblyPath = Path.Combine(searchPath, assemblyFileName);
-                if (File.Exists(assemblyPath))
+                var assemblyFile = new FileInfo(Path.Combine(searchPath, assemblyFileName));
+                if (assemblyFile.Exists)
                 {
                     try
                     {
-                        assembly = LoadFromFile(assemblyPath);
+                        assembly = LoadFromFile(assemblyFile.FullName);
                         return true;
                     }
                     catch (Exception ex) when (