Fix missing IUnitTestRuntimeProvider (#85)

Fixes: #73

SpecFlow.DependencyInjection.Tests/UnitTestRuntimeProvider.feature

@@ -0,0 +1,6 @@
+Feature: UnitTestRuntimeProvider
+    Issue #73: Unable to resolve IUnitTestRuntimeProvider
+    https://github.com/solidtoken/SpecFlow.DependencyInjection/issues/73
+
+Scenario: Assert IUnitTestRuntimeProvider is available
+	Then verify that IUnitTestRuntimeProvider is correctly injected

SpecFlow.DependencyInjection.Tests/UnitTestRuntimeProviderSteps.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using TechTalk.SpecFlow;
+using TechTalk.SpecFlow.UnitTestProvider;
+using Xunit;
+
+namespace SolidToken.SpecFlow.DependencyInjection.Tests
+{
+    [Binding]
+    public class UnitTestRuntimeProviderSteps
+    {
+        private readonly IUnitTestRuntimeProvider _unitTestRuntimeProvider;
+
+        public UnitTestRuntimeProviderSteps(IUnitTestRuntimeProvider unitTestRuntimeProvider)
+        {
+            _unitTestRuntimeProvider = unitTestRuntimeProvider;
+        }
+
+        [Then(@"verify that IUnitTestRuntimeProvider is correctly injected")]
+        public void ThenVerifyThatIUnitTestRuntimeProviderIsCorrectlyInjected()
+        {
+            Assert.NotNull(_unitTestRuntimeProvider);
+        }
+    }
+}

SpecFlow.DependencyInjection/DependencyInjectionPlugin.cs

@@ -155,6 +155,7 @@ private static void RegisterProxyBindings(IObjectContainer objectContainer, ISer
             services.AddSingleton(sp => objectContainer.Resolve<IStepTextAnalyzer>());
             services.AddSingleton(sp => objectContainer.Resolve<IRuntimePluginLoader>());
             services.AddSingleton(sp => objectContainer.Resolve<IBindingAssemblyLoader>());
+            services.AddSingleton(sp => objectContainer.Resolve<IUnitTestRuntimeProvider>());
 
             services.AddTransient(sp =>
             {