Fixed type solver for nested public types

Author: dvvrd

VSharp.API/VSharp.cs

@@ -179,7 +179,7 @@ public static Statistics Cover(Assembly assembly, int timeout = -1, string outpu
 
             foreach (var t in assembly.GetTypes())
             {
-                if (t.IsPublic)
+                if (t.IsPublic || t.IsNestedPublic)
                 {
                     foreach (var m in t.GetMethods(bindingFlags))
                     {

VSharp.CSharpUtils/DiagnosticsUtils.cs

@@ -7,4 +7,4 @@ private static bool DebuggerIsAttached()
     {
         return false;
     }
-}
+}

VSharp.SILI.Core/TypeSolver.fs

@@ -107,7 +107,7 @@ module TypeSolver =
                 | None -> sure <- false; assemblies
             for assembly in assemblies do
                 yield! assembly.GetExportedTypes() |> Seq.filter validate |> Seq.map ConcreteType
-            if supertypes |> Seq.forall (fun t -> t.IsPublic) then
+            if supertypes |> Seq.forall (fun t -> t.IsPublic || t.IsNestedPublic) then
                 yield mock supertypes |> MockType
         }