NH-3807 - Explore alternate way to set global settings in .NET Core.

Can't rely on app.xml for unit tests because there is no App Domains and
Assembly.GetEntryAssembly() isn't set correctly.

Author: ngbrown

src/NHibernate.Test/App.config

@@ -31,7 +31,7 @@
 			<property name="dialect">NHibernate.Dialect.MsSql2008Dialect</property>
 
 			<property name="connection.driver_class">NHibernate.Driver.SqlClientDriver, NHibernate.Driver.SqlClient</property> <!-- Shouldn't be necessary, but is required by some tests -->
-			<property name="connection.connection_string_name">TestConnectionString</property>
+			<property name="connection.connection_string">Server=localhost\sqlexpress;Database=nhibernate;Integrated Security=SSPI</property>
 			<property name="connection.provider">NHibernate.Test.DebugConnectionProvider, NHibernate.Test</property>
 			<property name="connection.isolation">ReadCommitted</property> <!-- See System.Data.IsolationLevel for valid values -->
 			<!--property name="connection.connection_string" /-->

src/NHibernate.Test/ConnectionStringTest/NamedConnectionStringFixture.cs

@@ -32,6 +32,7 @@ public void ConnectionStringInSettingsOverrideNamedConnectionSTring()
 			Assert.AreEqual(conStr, cp.PublicConnectionString);
 		}
 
+#if !NETCOREAPP2_0
 		[Test]
 		public void CanGetNamedConnectionStringFromConfiguration()
 		{
@@ -42,6 +43,7 @@ public void CanGetNamedConnectionStringFromConfiguration()
 
 			Assert.AreEqual("TestConnectionString-TestConnectionString", cp.PublicConnectionString);
 		}
+#endif
 	}
 
 	public class MockConnectionProvider : ConnectionProvider

src/NHibernate.Test/TestsContext.cs

@@ -0,0 +1,27 @@
+using System.Configuration;
+using System.IO;
+using System.Xml;
+
+using NHibernate.Cfg.ConfigurationSchema;
+using NUnit.Framework;
+
+namespace NHibernate.Test
+{
+	[SetUpFixture]
+	public class TestsContext
+    {
+		[OneTimeSetUp]
+		public void RunBeforeAnyTests()
+		{
+			string assemblyPath = Path.Combine(TestContext.CurrentContext.TestDirectory, @"NHibernate.Test.dll");
+			var configuration = ConfigurationManager.OpenExeConfiguration(assemblyPath);
+			ConfigurationSection configSection = configuration.GetSection(CfgXmlHelper.CfgSectionName);
+
+			using (XmlTextReader reader = new XmlTextReader(configSection.SectionInformation.GetRawXml(), XmlNodeType.Document, null))
+			{
+				HibernateConfiguration config = new HibernateConfiguration(reader);
+				NHibernate.Cfg.Environment.InitializeGlobalProperties(config);
+			}
+		}
+	}
+}

src/NHibernate/Cfg/Environment.cs

@@ -209,27 +209,18 @@ static Environment()
 			}
 
 			GlobalProperties = new Dictionary<string, string>();
-			GlobalProperties[PropertyUseReflectionOptimizer] = bool.TrueString;
-			LoadGlobalPropertiesFromAppConfig();
-			VerifyProperties(GlobalProperties);
-
-			BytecodeProviderInstance = BuildBytecodeProvider(GlobalProperties);
-			EnableReflectionOptimizer = PropertiesHelper.GetBoolean(PropertyUseReflectionOptimizer, GlobalProperties);
-
-			if (EnableReflectionOptimizer)
-			{
-				log.Info("Using reflection optimizer");
-			}
+			InitializeGlobalProperties(LoadGlobalPropertiesFromAppConfig());
 		}
 
-		private static void LoadGlobalPropertiesFromAppConfig()
+		private static IHibernateConfiguration LoadGlobalPropertiesFromAppConfig()
 		{
-			object config = ConfigurationManager.GetSection(CfgXmlHelper.CfgSectionName);
+			var configuration = ConfigurationManager.OpenExeConfiguration(Assembly.GetEntryAssembly().Location);
+			object config = configuration.GetSection(CfgXmlHelper.CfgSectionName);
 
 			if (config == null)
 			{
 				log.Info(string.Format("{0} section not found in application configuration file", CfgXmlHelper.CfgSectionName));
-				return;
+				return null;
 			}
 
 			var nhConfig = config as IHibernateConfiguration;
@@ -239,18 +230,39 @@ private static void LoadGlobalPropertiesFromAppConfig()
 					string.Format(
 						"{0} section handler, in application configuration file, is not IHibernateConfiguration, section ignored",
 						CfgXmlHelper.CfgSectionName));
-				return;
+				return null;
 			}
 
-			GlobalProperties[PropertyBytecodeProvider] = nhConfig.ByteCodeProviderType;
-			GlobalProperties[PropertyUseReflectionOptimizer] = nhConfig.UseReflectionOptimizer.ToString();
-			if (nhConfig.SessionFactory != null)
+			return nhConfig;
+		}
+
+		public static void InitializeGlobalProperties(IHibernateConfiguration nhConfig)
+		{
+			GlobalProperties.Clear();
+			GlobalProperties[PropertyUseReflectionOptimizer] = bool.TrueString;
+
+			if (nhConfig != null)
 			{
-				foreach (var kvp in nhConfig.SessionFactory.Properties)
+				GlobalProperties[PropertyBytecodeProvider] = nhConfig.ByteCodeProviderType;
+				GlobalProperties[PropertyUseReflectionOptimizer] = nhConfig.UseReflectionOptimizer.ToString();
+				if (nhConfig.SessionFactory != null)
 				{
-					GlobalProperties[kvp.Key] = kvp.Value;
+					foreach (var kvp in nhConfig.SessionFactory.Properties)
+					{
+						GlobalProperties[kvp.Key] = kvp.Value;
+					}
 				}
 			}
+
+			VerifyProperties(GlobalProperties);
+
+			BytecodeProviderInstance = BuildBytecodeProvider(GlobalProperties);
+			EnableReflectionOptimizer = PropertiesHelper.GetBoolean(PropertyUseReflectionOptimizer, GlobalProperties);
+
+			if (EnableReflectionOptimizer)
+			{
+				log.Info("Using reflection optimizer");
+			}
 		}
 
 		internal static void ResetSessionFactoryProperties()