From 2ccd581fa7d9e7af91b4dcd5f138ffa3ecaa28c2 Mon Sep 17 00:00:00 2001
From: Aleksbgbg <kozichka01@abv.bg>
Date: Wed, 19 Jun 2019 12:25:39 +0100
Subject: [PATCH] [ServiceEntry] Add hashable class that contains a service
 type and service key, to store in a dictionary and access by both type and
 key.

---
 Wingman.Tests/Container/ServiceEntryTests.cs | 61 ++++++++++++++++++++
 Wingman/Container/ServiceEntry.cs            | 33 +++++++++++
 2 files changed, 94 insertions(+)
 create mode 100644 Wingman.Tests/Container/ServiceEntryTests.cs
 create mode 100644 Wingman/Container/ServiceEntry.cs

diff --git a/Wingman.Tests/Container/ServiceEntryTests.cs b/Wingman.Tests/Container/ServiceEntryTests.cs
new file mode 100644
index 0000000..7536d8c
--- /dev/null
+++ b/Wingman.Tests/Container/ServiceEntryTests.cs
@@ -0,0 +1,61 @@
+namespace Wingman.Tests.Container
+{
+    using Wingman.Container;
+
+    using Xunit;
+
+    public class ServiceEntryTests
+    {
+        [Fact]
+        public void TestIdenticalEntriesIdenticalHashCode()
+        {
+            ServiceEntry serviceEntry0 = new ServiceEntry(typeof(IService), "SomeKey");
+            ServiceEntry serviceEntry1 = new ServiceEntry(typeof(IService), "SomeKey");
+
+            int hashCode0 = serviceEntry0.GetHashCode();
+            int hashCode1 = serviceEntry1.GetHashCode();
+
+            Assert.Equal(hashCode0, hashCode1);
+        }
+
+        [Fact]
+        public void TestNullServiceMatches()
+        {
+            ServiceEntry serviceEntry0 = new ServiceEntry(typeof(IService), null);
+            ServiceEntry serviceEntry1 = new ServiceEntry(typeof(IService), null);
+
+            int hashCode0 = serviceEntry0.GetHashCode();
+            int hashCode1 = serviceEntry1.GetHashCode();
+
+            Assert.Equal(hashCode0, hashCode1);
+        }
+
+        [Fact]
+        public void TestNullKeyMatches()
+        {
+            ServiceEntry serviceEntry0 = new ServiceEntry(null, "SomeKey");
+            ServiceEntry serviceEntry1 = new ServiceEntry(null, "SomeKey");
+
+            int hashCode0 = serviceEntry0.GetHashCode();
+            int hashCode1 = serviceEntry1.GetHashCode();
+
+            Assert.Equal(hashCode0, hashCode1);
+        }
+
+        [Fact]
+        public void TestDifferentEntriesDifferentHashCode()
+        {
+            ServiceEntry serviceEntry0 = new ServiceEntry(typeof(IService), "SomeKey");
+            ServiceEntry serviceEntry1 = new ServiceEntry(typeof(IService1), "SomeKey");
+
+            int hashCode0 = serviceEntry0.GetHashCode();
+            int hashCode1 = serviceEntry1.GetHashCode();
+
+            Assert.NotEqual(hashCode0, hashCode1);
+        }
+
+        private interface IService { }
+
+        private interface IService1 { }
+    }
+}
\ No newline at end of file
diff --git a/Wingman/Container/ServiceEntry.cs b/Wingman/Container/ServiceEntry.cs
new file mode 100644
index 0000000..46d5685
--- /dev/null
+++ b/Wingman/Container/ServiceEntry.cs
@@ -0,0 +1,33 @@
+namespace Wingman.Container
+{
+    using System;
+
+    internal class ServiceEntry
+    {
+        private readonly Type _serviceType;
+
+        private readonly string _key;
+
+        internal ServiceEntry(Type serviceType, string key)
+        {
+            _serviceType = serviceType;
+            _key = key;
+        }
+
+        public override int GetHashCode()
+        {
+            unchecked
+            {
+                const int prime1 = 17;
+                const int prime2 = 23;
+
+                int hash = prime1;
+
+                hash = (hash * prime2) + (_serviceType?.GetHashCode() ?? 0);
+                hash = (hash * prime2) + (_key?.GetHashCode() ?? 0);
+
+                return hash;
+            }
+        }
+    }
+}
\ No newline at end of file