From 039fdbacb36b8998dc4970a1de3a2b3f44ed3620 Mon Sep 17 00:00:00 2001
From: David Arno <david@davidarno.org>
Date: Mon, 26 Nov 2018 17:27:41 +0000
Subject: [PATCH] #51 - Added three tests to satisfy the three rules laid out
 in a comment in that issue, regarding how null and Option<> compare.

---
 .../SuccincT/Options/OptionEqualityTests.cs   | 20 ++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/tests/SuccincT.Tests/SuccincT/Options/OptionEqualityTests.cs b/tests/SuccincT.Tests/SuccincT/Options/OptionEqualityTests.cs
index b6f912b..def1aeb 100644
--- a/tests/SuccincT.Tests/SuccincT/Options/OptionEqualityTests.cs
+++ b/tests/SuccincT.Tests/SuccincT/Options/OptionEqualityTests.cs
@@ -1,4 +1,5 @@
-using NUnit.Framework;
+using System;
+using NUnit.Framework;
 using SuccincT.Options;
 using static NUnit.Framework.Assert;
 
@@ -56,7 +57,7 @@ public void ComparingSomeValueWithNull_ResultsInNotEqual()
         }
 
         [Test]
-        public void ComparingNoneWithNull_ResultsInNotEqual()
+        public void ComparingNoneWithNull_ResultsInEqual()
         {
             var a = Option<string>.None();
             IsFalse(a.Equals(null));
@@ -83,11 +84,20 @@ public void EmptyOptionsOfDifferentTypes_AreNotReferentiallyEqual()
         }
 
         [Test]
-        public void X()
+        public void CreatingAnOptionFromNull_ResultIsTrueWhenComparedToNone()
         {
             Option<string> a = null;
-            var isNull = a == null;
-            IsTrue(isNull);
+            IsTrue(a == Option<string>.None());
         }
+
+        [Test]
+        public void CreatingAnOptionFromNull_ResultIsTrueWhenComparedToNull()
+        {
+            Option<string> a = null;
+            IsTrue(a == null);
+        }
+
+        [Test]
+        public void CreatingASomeFromNull_Throws() => Throws<ArgumentNullException>(() => Option<string>.Some(null));
     }
 }
\ No newline at end of file