Remove dependency on mscorlib from portable C# script tests

src/Compilers/Core/CodeAnalysisTest/AnalyzerFileReferenceTests.cs

@@ -229,7 +229,7 @@ public class TestAnalyzer : DiagnosticAnalyzer
                 new SyntaxTree[] { CSharp.SyntaxFactory.ParseSyntaxTree(analyzerSource) },
                 new MetadataReference[]
                 {
-                    SystemRuntimeNetstandard13FacadeRef.Value,
+                    TestReferences.NetStandard13.SystemRuntime,
                     MetadataReference.CreateFromFile(immutable.Path),
                     MetadataReference.CreateFromFile(analyzer.Path)
                 },

src/Scripting/CSharpTest.Desktop/InteractiveSessionTests.cs

@@ -3,30 +3,37 @@
 
 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Diagnostics;
+using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.CSharp.Scripting;
 using Microsoft.CodeAnalysis.Scripting;
 using Microsoft.CodeAnalysis.Scripting.Hosting;
 using Microsoft.CodeAnalysis.Scripting.Test;
 using Microsoft.CodeAnalysis.Test.Utilities;
 using Roslyn.Test.Utilities;
 using Xunit;
-using TestBase = PortableTestUtils::Roslyn.Test.Utilities.TestBase;
 using AssertEx = PortableTestUtils::Roslyn.Test.Utilities.AssertEx;
+using TestBase = PortableTestUtils::Roslyn.Test.Utilities.TestBase;
+using WorkItemAttribute = PortableTestUtils::Roslyn.Test.Utilities.WorkItemAttribute;
 
 namespace Microsoft.CodeAnalysis.CSharp.Scripting.Test
 {
     using static TestCompilationFactory;
     using DiagnosticExtensions = PortableTestUtils::Microsoft.CodeAnalysis.DiagnosticExtensions;
+    using TestReferences = PortableTestUtils::TestReferences;
 
     public class InteractiveSessionTests : TestBase
     {
+        private static readonly CSharpCompilationOptions s_signedDll =
+           new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary, cryptoPublicKey: TestResources.TestKeys.PublicKey_ce65828c82a341f2);
+
+        private static readonly CSharpCompilationOptions s_signedDll2 =
+            new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary, cryptoPublicKey: TestResources.TestKeys.PublicKey_ce65828c82a341f2);
+
         [Fact]
         public async Task CompilationChain_GlobalImportsRebinding()
         {
@@ -362,8 +369,11 @@ public void References_Versioning_StrongNames2()
         [Fact]
         public void References_Versioning_WeakNames1()
         {
-            var c1 = Temp.CreateFile(extension: ".dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib(@"[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")] public class C {}", assemblyName: "C").EmitToArray());
-            var c2 = Temp.CreateFile(extension: ".dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib(@"[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")] public class C {}", assemblyName: "C").EmitToArray());
+            var c1 = Temp.CreateFile(extension: ".dll").WriteAllBytes(
+                CreateCSharpCompilation(@"[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")] public class C {}", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, assemblyName: "C").EmitToArray());
+
+            var c2 = Temp.CreateFile(extension: ".dll").WriteAllBytes(
+                CreateCSharpCompilation(@"[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")] public class C {}", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, assemblyName: "C").EmitToArray());
 
             var result = CSharpScript.EvaluateAsync($@"
 #r ""{c1.Path}""
@@ -378,8 +388,11 @@ public void References_Versioning_WeakNames1()
         [Fact]
         public void References_Versioning_WeakNames2()
         {
-            var c1 = Temp.CreateFile(extension: ".dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib(@"[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")] public class C {}", assemblyName: "C").EmitToArray());
-            var c2 = Temp.CreateFile(extension: ".dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib(@"[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")] public class C {}", assemblyName: "C").EmitToArray());
+            var c1 = Temp.CreateFile(extension: ".dll").WriteAllBytes(
+                CreateCSharpCompilation(@"[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")] public class C {}", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, assemblyName: "C").EmitToArray());
+
+            var c2 = Temp.CreateFile(extension: ".dll").WriteAllBytes(
+                CreateCSharpCompilation(@"[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")] public class C {}", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, assemblyName: "C").EmitToArray());
 
             var result = CSharpScript.Create($@"
 #r ""{c1.Path}""
@@ -395,8 +408,11 @@ public void References_Versioning_WeakNames2()
         [Fact]
         public void References_Versioning_WeakNames3()
         {
-            var c1 = Temp.CreateFile(extension: ".dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib(@"[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")] public class C {}", assemblyName: "C").EmitToArray());
-            var c2 = Temp.CreateFile(extension: ".dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib(@"[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")] public class C {}", assemblyName: "C").EmitToArray());
+            var c1 = Temp.CreateFile(extension: ".dll").WriteAllBytes(
+                CreateCSharpCompilation(@"[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")] public class C {}", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, assemblyName: "C").EmitToArray());
+
+            var c2 = Temp.CreateFile(extension: ".dll").WriteAllBytes(
+                CreateCSharpCompilation(@"[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")] public class C {}", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, assemblyName: "C").EmitToArray());
 
             var script0 = CSharpScript.Create($@"
 #r ""{c1.Path}""
@@ -545,7 +561,7 @@ public async Task MissingRefrencesAutoResolution()
         [Fact]
         public void HostObjectInInMemoryAssembly()
         {
-            var lib = CreateCSharpCompilationWithMscorlib("public class C { public int X = 1, Y = 2; }", "HostLib");
+            var lib = CreateCSharpCompilation("public class C { public int X = 1, Y = 2; }", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, "HostLib");
             var libImage = lib.EmitToArray();
             var libRef = MetadataImageReference.CreateFromImage(libImage);
 
@@ -567,5 +583,541 @@ public void HostObjectInInMemoryAssembly()
                 Assert.Equal(3, result);
             }
         }
+
+
+        [Fact]
+        public async Task SharedLibCopy_Identical_Weak()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase = CreateCSharpCompilation(@"
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib2Name);
+
+            var libBaseImage = libBase.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1();");
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+            var s3 = await s2.ContinueWithAsync($@"var l2 = new Lib2();");
+            var s4 = await s3.ContinueWithAsync($@"l2.libBase.X");
+
+            var c4 = s4.Script.GetCompilation();
+            c4.VerifyAssemblyAliases(
+                lib2Name,
+                lib1Name,
+                "mscorlib",
+                libBaseName + ": <implicit>,global");
+
+            var libBaseRefAndSymbol = c4.GetBoundReferenceManager().GetReferencedAssemblies().ToArray()[3];
+            Assert.Equal(fileBase1.Path, ((PortableExecutableReference)libBaseRefAndSymbol.Key).FilePath);
+        }
+
+        [Fact]
+        public async Task SharedLibCopy_Identical_Strong()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase = CreateCSharpCompilation(@"
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib2Name);
+
+            var libBaseImage = libBase.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1();");
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+            var s3 = await s2.ContinueWithAsync($@"var l2 = new Lib2();");
+            var s4 = await s3.ContinueWithAsync($@"l2.libBase.X");
+
+            var c4 = s4.Script.GetCompilation();
+            c4.VerifyAssemblyAliases(
+                lib2Name,
+                lib1Name,
+                "mscorlib",
+                libBaseName + ": <implicit>,global");
+
+            var libBaseRefAndSymbol = c4.GetBoundReferenceManager().GetReferencedAssemblies().ToArray()[3];
+            Assert.Equal(fileBase1.Path, ((PortableExecutableReference)libBaseRefAndSymbol.Key).FilePath);
+        }
+
+        [Fact]
+        public async Task SharedLibCopy_SameVersion_Weak_DifferentContent()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase1 = CreateCSharpCompilation(@"
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
+
+            var libBase2 = CreateCSharpCompilation(@"
+public class LibBase
+{
+    public readonly int X = 2;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
+
+            var libBase1Image = libBase1.EmitToArray();
+            var libBase2Image = libBase2.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1();");
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+
+            bool exceptionSeen = false;
+            try
+            {
+                await s2.ContinueWithAsync($@"var l2 = new Lib2();");
+            }
+            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
+            {
+                exceptionSeen = true;
+            }
+
+            Assert.True(exceptionSeen);
+        }
+
+        [Fact]
+        public async Task SharedLibCopy_SameVersion_Strong_DifferentContent()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase1 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+
+            var libBase2 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 2;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
+
+            var libBase1Image = libBase1.EmitToArray();
+            var libBase2Image = libBase2.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+
+            bool exceptionSeen = false;
+            try
+            {
+                await s2.ContinueWithAsync($@"new Lib2().libBase.X");
+            }
+            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
+            {
+                exceptionSeen = true;
+            }
+
+            Assert.True(exceptionSeen);
+        }
+
+        [Fact]
+        public async Task SharedLibCopy_SameVersion_StrongWeak_DifferentContent()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase1 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+
+            var libBase2 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 2;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
+
+            var libBase1Image = libBase1.EmitToArray();
+            var libBase2Image = libBase2.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+
+            bool exceptionSeen = false;
+            try
+            {
+                await s2.ContinueWithAsync($@"new Lib2().libBase.X");
+            }
+            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
+            {
+                exceptionSeen = true;
+            }
+
+            Assert.True(exceptionSeen);
+        }
+
+        [Fact]
+        public async Task SharedLibCopy_SameVersion_StrongDifferentPKT_DifferentContent()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase1 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+
+            var libBase2 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 2;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll2);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
+
+            var libBase1Image = libBase1.EmitToArray();
+            var libBase2Image = libBase2.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+
+            bool exceptionSeen = false;
+            try
+            {
+                await s2.ContinueWithAsync($@"new Lib2().libBase.X");
+            }
+            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
+            {
+                exceptionSeen = true;
+            }
+
+            Assert.True(exceptionSeen);
+        }
+
+        [Fact]
+        public async Task SharedLibCopy_DifferentVersion_Weak()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase1 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
+
+            var libBase2 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 2;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase2.ToMetadataReference() }, lib2Name);
+
+            var libBase1Image = libBase1.EmitToArray();
+            var libBase2Image = libBase2.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1().libBase.X;");
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+
+            bool exceptionSeen = false;
+            try
+            {
+                await s2.ContinueWithAsync($@"var l2 = new Lib2().libBase.X;");
+            }
+            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
+            {
+                exceptionSeen = true;
+            }
+
+            Assert.True(exceptionSeen);
+        }
+
+        [Fact]
+        public async Task SharedLibCopy_DifferentVersion_Strong()
+        {
+            string libBaseName = "LibBase_" + Guid.NewGuid();
+            string lib1Name = "Lib1_" + Guid.NewGuid();
+            string lib2Name = "Lib2_" + Guid.NewGuid();
+
+            var libBase1 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 1;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+
+            var libBase2 = CreateCSharpCompilation(@"
+[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")]
+public class LibBase
+{
+    public readonly int X = 2;
+}
+", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+
+            var lib1 = CreateCSharpCompilation(@"
+public class Lib1
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
+
+            var lib2 = CreateCSharpCompilation(@"
+public class Lib2
+{
+    public LibBase libBase = new LibBase();
+}
+", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase2.ToMetadataReference() }, lib2Name);
+
+            var libBase1Image = libBase1.EmitToArray();
+            var libBase2Image = libBase2.EmitToArray();
+            var lib1Image = lib1.EmitToArray();
+            var lib2Image = lib2.EmitToArray();
+
+            var root = Temp.CreateDirectory();
+            var dir1 = root.CreateDirectory("1");
+            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
+            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
+
+            var dir2 = root.CreateDirectory("2");
+            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
+            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
+
+            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
+            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
+            Assert.Equal(1, s1.ReturnValue);
+            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
+            var s3 = await s2.ContinueWithAsync($@"new Lib2().libBase.X");
+            Assert.Equal(2, s3.ReturnValue);
+        }
+
+        [Fact, WorkItem(6457, "https://github.com/dotnet/roslyn/issues/6457")]
+        public async Task MissingReferencesReuse()
+        {
+            var source = @"
+public class C
+{
+    public System.Diagnostics.Process P;
+}
+";
+
+            var lib = CSharpCompilation.Create(
+                "Lib",
+                new[] { SyntaxFactory.ParseSyntaxTree(source) },
+                new[] { TestReferences.NetFx.v4_0_30319.mscorlib, TestReferences.NetFx.v4_0_30319.System },
+                new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
+
+            var libFile = Temp.CreateFile("lib").WriteAllBytes(lib.EmitToArray());
+
+            var s0 = await CSharpScript.RunAsync("C c;", ScriptOptions.Default.WithReferences(libFile.Path));
+            var s1 = await s0.ContinueWithAsync("c = new C()");
+        }
     }
 }

src/Scripting/CSharpTest/CommandLineRunnerTests.cs

@@ -577,16 +577,16 @@ public void ReferenceSearchPaths1()
 ");
 
             var dir1 = Temp.CreateDirectory();
-            dir1.CreateFile("1.dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib("public class C1 {}", "1").EmitToArray());
+            dir1.CreateFile("1.dll").WriteAllBytes(CreateCSharpCompilationWithCorlib("public class C1 {}", "1").EmitToArray());
 
             var dir2 = Temp.CreateDirectory();
-            dir2.CreateFile("2.dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib("public class C2 {}", "2").EmitToArray());
+            dir2.CreateFile("2.dll").WriteAllBytes(CreateCSharpCompilationWithCorlib("public class C2 {}", "2").EmitToArray());
 
             var dir3 = Temp.CreateDirectory();
-            dir3.CreateFile("3.dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib("public class C3 {}", "3").EmitToArray());
+            dir3.CreateFile("3.dll").WriteAllBytes(CreateCSharpCompilationWithCorlib("public class C3 {}", "3").EmitToArray());
 
             var dir4 = Temp.CreateDirectory();
-            dir4.CreateFile("4.dll").WriteAllBytes(CreateCSharpCompilationWithMscorlib("public class C4 {}", "4").EmitToArray());
+            dir4.CreateFile("4.dll").WriteAllBytes(CreateCSharpCompilationWithCorlib("public class C4 {}", "4").EmitToArray());
 
             var runner = CreateRunner(new[] { "/r:4.dll", $"/lib:{dir1.Path}", $"/libpath:{dir2.Path}", $"/libpaths:{dir3.Path};{dir4.Path}", main.Path });
 

src/Scripting/CSharpTest/InteractiveSessionTests.cs

@@ -30,12 +30,6 @@ public class HostModel
 
     public class InteractiveSessionTests : TestBase
     {
-        private static readonly CSharpCompilationOptions s_signedDll =
-            new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary, cryptoPublicKey: TestResources.TestKeys.PublicKey_ce65828c82a341f2);
-
-        private static readonly CSharpCompilationOptions s_signedDll2 =
-            new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary, cryptoPublicKey: TestResources.TestKeys.PublicKey_ce65828c82a341f2);
-
         internal static readonly Assembly HostAssembly = typeof(InteractiveSessionTests).GetTypeInfo().Assembly;
 
         #region Namespaces, Types
@@ -1134,579 +1128,69 @@ public void AwaitChain2()
         [Fact]
         public void ReferenceDirective_FileWithDependencies()
         {
-            string file1 = Temp.CreateFile().WriteAllBytes(TestResources.MetadataTests.InterfaceAndClass.CSClasses01).Path;
-            string file2 = Temp.CreateFile().WriteAllBytes(TestResources.MetadataTests.InterfaceAndClass.CSInterfaces01).Path;
-
-            // ICSPropImpl in CSClasses01.dll implements ICSProp in CSInterfces01.dll.
-            object result = CSharpScript.EvaluateAsync(@"
-#r """ + file1 + @"""
-#r """ + file2 + @"""
-new Metadata.ICSPropImpl()
-").Result;
-            Assert.NotNull(result);
-        }
-
-        [Fact]
-        public void ReferenceDirective_RelativeToBaseParent()
-        {
-            string path = Temp.CreateFile().WriteAllBytes(TestResources.MetadataTests.InterfaceAndClass.CSClasses01).Path;
-            string fileName = Path.GetFileName(path);
-            string dir = Path.Combine(Path.GetDirectoryName(path), "subdir");
-
-            var script = CSharpScript.Create($@"#r ""..\{fileName}""",
-                ScriptOptions.Default.WithFilePath(Path.Combine(dir, "a.csx")));
-
-            script.GetCompilation().VerifyDiagnostics();
-        }
-
-        [Fact]
-        public void ReferenceDirective_RelativeToBaseRoot()
-        {
-            string path = Temp.CreateFile().WriteAllBytes(TestResources.MetadataTests.InterfaceAndClass.CSClasses01).Path;
-            string root = Path.GetPathRoot(path);
-            string unrooted = path.Substring(root.Length);
-
-            string dir = Path.Combine(root, "foo", "bar", "baz");
-
-            var script = CSharpScript.Create($@"#r ""\{unrooted}""",
-                ScriptOptions.Default.WithFilePath(Path.Combine(dir, "a.csx")));
-
-            script.GetCompilation().VerifyDiagnostics();
-        }
-
-        [Fact, WorkItem(6457, "https://github.com/dotnet/roslyn/issues/6457")]
-        public async Task MissingReferencesReuse()
-        {
-            var source = @"
-public class C
-{
-    public System.Diagnostics.Process P;
-}
-";
-
-            var lib = CSharpCompilation.Create(
-                "Lib",
-                new[] { SyntaxFactory.ParseSyntaxTree(source) },
-                new[] { TestReferences.NetFx.v4_0_30319.mscorlib, TestReferences.NetFx.v4_0_30319.System },
-                new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
-
-            var libFile = Temp.CreateFile("lib").WriteAllBytes(lib.EmitToArray());
-
-            var s0 = await CSharpScript.RunAsync("C c;", ScriptOptions.Default.WithReferences(libFile.Path));
-            var s1 = await s0.ContinueWithAsync("c = new C()");
-        }
-
-        [Fact]
-        public async Task SharedLibCopy_Identical_Weak()
-        {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase = CreateCSharpCompilation(@"
-public class LibBase
-{
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
-
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib1Name);
-
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib2Name);
-
-            var libBaseImage = libBase.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
-
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
-
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
-
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1();");
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-            var s3 = await s2.ContinueWithAsync($@"var l2 = new Lib2();");
-            var s4 = await s3.ContinueWithAsync($@"l2.libBase.X");
-
-            var c4 = s4.Script.GetCompilation();
-            c4.VerifyAssemblyAliases(
-                lib2Name,
-                lib1Name,
-                "mscorlib",
-                libBaseName + ": <implicit>,global");
-
-            var libBaseRefAndSymbol = c4.GetBoundReferenceManager().GetReferencedAssemblies().ToArray()[3];
-            Assert.Equal(fileBase1.Path, ((PortableExecutableReference)libBaseRefAndSymbol.Key).FilePath);
-        }
-
-        [Fact]
-        public async Task SharedLibCopy_Identical_Strong()
-        {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase = CreateCSharpCompilation(@"
-public class LibBase
-{
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
-
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib1Name);
-
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase.ToMetadataReference() }, lib2Name);
-
-            var libBaseImage = libBase.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
-
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
-
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBaseImage);
-
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1();");
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-            var s3 = await s2.ContinueWithAsync($@"var l2 = new Lib2();");
-            var s4 = await s3.ContinueWithAsync($@"l2.libBase.X");
-
-            var c4 = s4.Script.GetCompilation();
-            c4.VerifyAssemblyAliases(
-                lib2Name,
-                lib1Name,
-                "mscorlib",
-                libBaseName + ": <implicit>,global");
-
-            var libBaseRefAndSymbol = c4.GetBoundReferenceManager().GetReferencedAssemblies().ToArray()[3];
-            Assert.Equal(fileBase1.Path, ((PortableExecutableReference)libBaseRefAndSymbol.Key).FilePath);
-        }
-
-        [Fact]
-        public async Task SharedLibCopy_SameVersion_Weak_DifferentContent()
-        {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase1 = CreateCSharpCompilation(@"
-public class LibBase
-{
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
-
-            var libBase2 = CreateCSharpCompilation(@"
-public class LibBase
-{
-    public readonly int X = 2;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
-
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
-
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
-
-            var libBase1Image = libBase1.EmitToArray();
-            var libBase2Image = libBase2.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
-
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
-
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
-
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1();");
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-
-            bool exceptionSeen = false;
-            try
-            {
-                await s2.ContinueWithAsync($@"var l2 = new Lib2();");
-            }
-            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
-            {
-                exceptionSeen = true;
-            }
-
-            Assert.True(exceptionSeen);
-        }
-
-        [Fact]
-        public async Task SharedLibCopy_SameVersion_Strong_DifferentContent()
-        {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase1 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+            var file1 = Temp.CreateFile();
+            var file2 = Temp.CreateFile();
 
-            var libBase2 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
+            var lib1 = CreateCSharpCompilationWithCorlib(@"
+public interface I
 {
-    public readonly int X = 2;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
-
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
-
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
-
-            var libBase1Image = libBase1.EmitToArray();
-            var libBase2Image = libBase2.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
-
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
-
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
-
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-
-            bool exceptionSeen = false;
-            try
-            {
-                await s2.ContinueWithAsync($@"new Lib2().libBase.X");
-            }
-            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
-            {
-                exceptionSeen = true;
-            }
-
-            Assert.True(exceptionSeen);
-        }
-
-        [Fact]
-        public async Task SharedLibCopy_SameVersion_StrongWeak_DifferentContent()
-        {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase1 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
-
-            var libBase2 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 2;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
-
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
-
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
-
-            var libBase1Image = libBase1.EmitToArray();
-            var libBase2Image = libBase2.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
-
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
-
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
-
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-
-            bool exceptionSeen = false;
-            try
-            {
-                await s2.ContinueWithAsync($@"new Lib2().libBase.X");
-            }
-            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
-            {
-                exceptionSeen = true;
-            }
+    int F();
+}");
 
-            Assert.True(exceptionSeen);
-        }
+            lib1.Emit(file1.Path);
 
-        [Fact]
-        public async Task SharedLibCopy_SameVersion_StrongDifferentPKT_DifferentContent()
-        {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase1 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
+            var lib2 = CreateCSharpCompilation(@" 
+public class C : I
 {
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+    public int F() => 1;
+}", new MetadataReference[] { TestReferences.NetStandard13.SystemRuntime, lib1.ToMetadataReference() });
 
-            var libBase2 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 2;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll2);
-
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
+            lib2.Emit(file2.Path);
 
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib2Name);
-
-            var libBase1Image = libBase1.EmitToArray();
-            var libBase2Image = libBase2.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
-
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
-
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
-
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-
-            bool exceptionSeen = false;
-            try
-            {
-                await s2.ContinueWithAsync($@"new Lib2().libBase.X");
-            }
-            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
-            {
-                exceptionSeen = true;
-            }
-
-            Assert.True(exceptionSeen);
+            object result = CSharpScript.EvaluateAsync($@"
+#r ""{file1.Path}""
+#r ""{file2.Path}""
+new C()
+").Result;
+            Assert.NotNull(result);
         }
 
         [Fact]
-        public async Task SharedLibCopy_DifferentVersion_Weak()
+        public void ReferenceDirective_RelativeToBaseParent()
         {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase1 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
-
-            var libBase2 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 2;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName);
-
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
-
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase2.ToMetadataReference() }, lib2Name);
+            var file = Temp.CreateFile();
+            var lib = CreateCSharpCompilationWithCorlib("public class C {}");
+            lib.Emit(file.Path);
 
-            var libBase1Image = libBase1.EmitToArray();
-            var libBase2Image = libBase2.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
+            string dir = Path.Combine(Path.GetDirectoryName(file.Path), "subdir");
+            string libFileName = Path.GetFileName(file.Path);
+            string scriptPath = Path.Combine(dir, "a.csx");
 
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
-
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
-
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"var l1 = new Lib1().libBase.X;");
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-
-            bool exceptionSeen = false;
-            try
-            {
-                await s2.ContinueWithAsync($@"var l2 = new Lib2().libBase.X;");
-            }
-            catch (FileLoadException fileLoadEx) when (fileLoadEx.InnerException is InteractiveAssemblyLoaderException)
-            {
-                exceptionSeen = true;
-            }
+            var script = CSharpScript.Create(
+                $@"#r ""..\{libFileName}""",
+                ScriptOptions.Default.WithFilePath(scriptPath));
 
-            Assert.True(exceptionSeen);
+            script.GetCompilation().VerifyDiagnostics();
         }
 
         [Fact]
-        public async Task SharedLibCopy_DifferentVersion_Strong()
+        public void ReferenceDirective_RelativeToBaseRoot()
         {
-            string libBaseName = "LibBase_" + Guid.NewGuid();
-            string lib1Name = "Lib1_" + Guid.NewGuid();
-            string lib2Name = "Lib2_" + Guid.NewGuid();
-
-            var libBase1 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""1.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 1;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+            var file = Temp.CreateFile();
+            var lib = CreateCSharpCompilationWithCorlib("public class C {}");
+            lib.Emit(file.Path);
 
-            var libBase2 = CreateCSharpCompilation(@"
-[assembly: System.Reflection.AssemblyVersion(""2.0.0.0"")]
-public class LibBase
-{
-    public readonly int X = 2;
-}
-", new[] { TestReferences.NetFx.v4_0_30319.mscorlib }, libBaseName, s_signedDll);
+            string root = Path.GetPathRoot(file.Path);
+            string unrooted = file.Path.Substring(root.Length);
 
-            var lib1 = CreateCSharpCompilation(@"
-public class Lib1
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase1.ToMetadataReference() }, lib1Name);
-
-            var lib2 = CreateCSharpCompilation(@"
-public class Lib2
-{
-    public LibBase libBase = new LibBase();
-}
-", new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libBase2.ToMetadataReference() }, lib2Name);
-
-            var libBase1Image = libBase1.EmitToArray();
-            var libBase2Image = libBase2.EmitToArray();
-            var lib1Image = lib1.EmitToArray();
-            var lib2Image = lib2.EmitToArray();
-
-            var root = Temp.CreateDirectory();
-            var dir1 = root.CreateDirectory("1");
-            var file1 = dir1.CreateFile(lib1Name + ".dll").WriteAllBytes(lib1Image);
-            var fileBase1 = dir1.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase1Image);
+            string dir = Path.Combine(root, "foo", "bar", "baz");
+            string scriptPath = Path.Combine(dir, "a.csx");
 
-            var dir2 = root.CreateDirectory("2");
-            var file2 = dir2.CreateFile(lib2Name + ".dll").WriteAllBytes(lib2Image);
-            var fileBase2 = dir2.CreateFile(libBaseName + ".dll").WriteAllBytes(libBase2Image);
+            var script = CSharpScript.Create(
+                $@"#r ""\{unrooted}""",
+                ScriptOptions.Default.WithFilePath(scriptPath));
 
-            var s0 = await CSharpScript.RunAsync($@"#r ""{file1.Path}""");
-            var s1 = await s0.ContinueWithAsync($@"new Lib1().libBase.X");
-            Assert.Equal(1, s1.ReturnValue);
-            var s2 = await s1.ContinueWithAsync($@"#r ""{file2.Path}""");
-            var s3 = await s2.ContinueWithAsync($@"new Lib2().libBase.X");
-            Assert.Equal(2, s3.ReturnValue);
+            script.GetCompilation().VerifyDiagnostics();
         }
 
         [Fact]
@@ -1715,13 +1199,13 @@ public void ExtensionPriority1()
             string mainName = "Main_" + Guid.NewGuid();
             string libName = "Lib_" + Guid.NewGuid();
 
-            var libExe = TestCompilationFactory.CreateCSharpCompilationWithMscorlib(@"public class C { public string F = ""exe""; }", libName);
-            var libDll = TestCompilationFactory.CreateCSharpCompilationWithMscorlib(@"public class C { public string F = ""dll""; }", libName);
-            var libWinmd = TestCompilationFactory.CreateCSharpCompilationWithMscorlib(@"public class C { public string F = ""winmd""; }", libName);
+            var libExe = CreateCSharpCompilationWithCorlib(@"public class C { public string F = ""exe""; }", libName);
+            var libDll = CreateCSharpCompilationWithCorlib(@"public class C { public string F = ""dll""; }", libName);
+            var libWinmd = CreateCSharpCompilationWithCorlib(@"public class C { public string F = ""winmd""; }", libName);
 
             var main = CreateCSharpCompilation(
                 @"public static class M { public static readonly C X = new C(); }",
-                new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libExe.ToMetadataReference() },
+                new MetadataReference[] { TestReferences.NetStandard13.SystemRuntime, libExe.ToMetadataReference() },
                 mainName);
 
             var exeImage = libExe.EmitToArray();
@@ -1745,13 +1229,13 @@ public void ExtensionPriority2()
             string mainName = "Main_" + Guid.NewGuid();
             string libName = "Lib_" + Guid.NewGuid();
 
-            var libExe = TestCompilationFactory.CreateCSharpCompilationWithMscorlib(@"public class C { public string F = ""exe""; }", libName);
-            var libDll = TestCompilationFactory.CreateCSharpCompilationWithMscorlib(@"public class C { public string F = ""dll""; }", libName);
-            var libWinmd = TestCompilationFactory.CreateCSharpCompilationWithMscorlib(@"public class C { public string F = ""winmd""; }", libName);
+            var libExe = CreateCSharpCompilationWithCorlib(@"public class C { public string F = ""exe""; }", libName);
+            var libDll = CreateCSharpCompilationWithCorlib(@"public class C { public string F = ""dll""; }", libName);
+            var libWinmd = CreateCSharpCompilationWithCorlib(@"public class C { public string F = ""winmd""; }", libName);
 
             var main = CreateCSharpCompilation(
                 @"public static class M { public static readonly C X = new C(); }",
-                new MetadataReference[] { TestReferences.NetFx.v4_0_30319.mscorlib, libExe.ToMetadataReference() },
+                new MetadataReference[] { TestReferences.NetStandard13.SystemRuntime, libExe.ToMetadataReference() },
                 mainName);
 
             var exeImage = libExe.EmitToArray();
@@ -1779,7 +1263,7 @@ public class D { }
 public class E { }
 ";
 
-            var libRef = CreateCSharpCompilationWithMscorlib(source, "lib").EmitToImageReference();
+            var libRef = CreateCSharpCompilationWithCorlib(source, "lib").EmitToImageReference();
 
             var script = CSharpScript.Create(@"new C()",
                 ScriptOptions.Default.WithReferences(libRef.WithAliases(new[] { "Hidden" })).WithImports("Hidden::N"));

src/Scripting/CoreTestUtilities/TestCompilationFactory.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.VisualBasic;
 
@@ -9,28 +10,28 @@ internal static class TestCompilationFactory
     {
         // TODO: we need to clean up and refactor CreateCompilationWithMscorlib in compiler tests 
         // so that it can be used in portable tests.
-        internal static Compilation CreateCSharpCompilationWithMscorlib(string source, string assemblyName)
+        internal static Compilation CreateCSharpCompilationWithCorlib(string source, string assemblyName = null)
         {
             return CSharpCompilation.Create(
-                assemblyName,
+                assemblyName ?? Guid.NewGuid().ToString(),
                 new[] { CSharp.SyntaxFactory.ParseSyntaxTree(source) },
-                new[] { TestReferences.NetFx.v4_0_30319.mscorlib },
+                new[] { TestReferences.NetStandard13.SystemRuntime },
                 new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
         }
 
-        internal static Compilation CreateVisualBasicCompilationWithMscorlib(string source, string assemblyName)
+        internal static Compilation CreateVisualBasicCompilationWithCorlib(string source, string assemblyName = null)
         {
             return VisualBasicCompilation.Create(
-                assemblyName,
+                assemblyName ?? Guid.NewGuid().ToString(),
                 new[] { VisualBasic.SyntaxFactory.ParseSyntaxTree(source) },
-                new[] { TestReferences.NetFx.v4_0_30319.mscorlib },
+                new[] { TestReferences.NetStandard13.SystemRuntime },
                 new VisualBasicCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
         }
 
-        internal static Compilation CreateCSharpCompilation(string source, MetadataReference[] references, string assemblyName, CSharpCompilationOptions options = null)
+        internal static Compilation CreateCSharpCompilation(string source, MetadataReference[] references, string assemblyName = null, CSharpCompilationOptions options = null)
         {
             return CSharpCompilation.Create(
-                assemblyName,
+                assemblyName ?? Guid.NewGuid().ToString(),
                 new[] { CSharp.SyntaxFactory.ParseSyntaxTree(source) },
                 references,
                 options ?? new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));

src/Scripting/VisualBasicTest/CommandLineRunnerTests.vb

@@ -80,7 +80,7 @@ Type ""#help"" for more information.
 
         <Fact()>
         Public Sub TestReferenceDirective()
-            Dim file1 = Temp.CreateFile("1.dll").WriteAllBytes(TestCompilationFactory.CreateVisualBasicCompilationWithMscorlib("
+            Dim file1 = Temp.CreateFile("1.dll").WriteAllBytes(TestCompilationFactory.CreateVisualBasicCompilationWithCorlib("
 public Class C1
 Public Function Foo() As String
     Return ""Bar""

src/Test/Utilities/Desktop/TestHelpers.cs

@@ -120,7 +120,7 @@ public class TestAnalyzer : DiagnosticAnalyzer
                 new SyntaxTree[] { SyntaxFactory.ParseSyntaxTree(analyzerSource) },
                 new MetadataReference[]
                 {
-                    TestBase.SystemRuntimeNetstandard13FacadeRef.Value,
+                    TestReferences.NetStandard13.SystemRuntime,
                     MetadataReference.CreateFromFile(immutable.Path),
                     MetadataReference.CreateFromFile(analyzer.Path)
                 },

src/Test/Utilities/Shared/Mocks/TestReferences.cs

@@ -534,6 +534,23 @@ public static PortableExecutableReference mscorlib
         }
     }
 
+    public static class NetStandard13
+    {
+        private static PortableExecutableReference s_systemRuntime;
+        public static PortableExecutableReference SystemRuntime
+        {
+            get
+            {
+                if (s_systemRuntime == null)
+                {
+                    s_systemRuntime = AssemblyMetadata.CreateFromImage(TestResources.NetFX.ReferenceAssemblies_netstandard1_3.System_Runtime).GetReference(display: @"System.Runtime.dll (netstandard13 ref)");
+                }
+
+                return s_systemRuntime;
+            }
+        }
+    }
+
     public static class DiagnosticTests
     {
         public static class ErrTestLib01

src/Test/Utilities/Shared/TestBase.cs

@@ -526,11 +526,6 @@ public static MetadataReference SystemRuntimePP7Ref
             }
         }
 
-        public static Lazy<MetadataReference> SystemRuntimeNetstandard13FacadeRef { get; } =
-            new Lazy<MetadataReference>(() => AssemblyMetadata.CreateFromImage(
-                TestResources.NetFX.ReferenceAssemblies_netstandard1_3.System_Runtime)
-                .GetReference(display: "System.Runtime.dll"));
-
         private static MetadataReference s_FSharpTestLibraryRef;
         public static MetadataReference FSharpTestLibraryRef
         {