Handling Money Comparison with Null to solve issue #181

Author: MicheleRezk

commercetools.Sdk/Tests/commercetools.Sdk.Domain.Tests/MoneyTest.cs

@@ -1,3 +1,4 @@
+using System;
 using NodaMoney;
 using Xunit;
 
@@ -66,5 +67,18 @@ public void ConvertToMoney()
             Assert.Equal(123457, m.CentAmount);
             Assert.Equal("EUR", m.CurrencyCode);
         }
+        
+        [Fact]
+        public void MoneyComparison()
+        {
+            var m1 = new Money() { CurrencyCode = "EUR", CentAmount = 1234, FractionDigits = 2 };
+            Money m2 = null;
+            
+            Assert.False(m1 == m2);
+            Assert.True(m1 != m2);
+            Assert.False(m1 > m2);
+            Assert.False(m1 < m2);
+            Assert.False(m1.Equals(m2));
+        }
     }
 }

commercetools.Sdk/commercetools.Sdk.Domain/Common/BaseMoney.cs

@@ -32,41 +32,93 @@ public int CompareTo(object obj)
 
         public static bool operator <(BaseMoney moneyLeft, BaseMoney moneyRight)
         {
+            if (ReferenceEquals(moneyLeft, moneyRight))
+            {
+                return false;
+            }
+            if (ReferenceEquals(moneyLeft,null) || ReferenceEquals(moneyRight,null))
+            {
+                return false;
+            }
             return moneyLeft.CompareTo(moneyRight) < 0;
         }
 
         public static bool operator >(BaseMoney moneyLeft, BaseMoney moneyRight)
         {
+            if (ReferenceEquals(moneyLeft, moneyRight))
+            {
+                return false;
+            }
+            if (ReferenceEquals(moneyLeft,null) || ReferenceEquals(moneyRight,null))
+            {
+                return false;
+            }
             return moneyLeft.CompareTo(moneyRight) > 0;
         }
 
         public static bool operator <=(BaseMoney moneyLeft, BaseMoney moneyRight)
         {
+            if (ReferenceEquals(moneyLeft, moneyRight))
+            {
+                return false;
+            }
+            if (ReferenceEquals(moneyLeft,null) || ReferenceEquals(moneyRight,null))
+            {
+                return false;
+            }
             return moneyLeft.CompareTo(moneyRight) <= 0;
         }
 
         public static bool operator >=(BaseMoney moneyLeft, BaseMoney moneyRight)
         {
+            if (ReferenceEquals(moneyLeft, moneyRight))
+            {
+                return false;
+            }
+            if (ReferenceEquals(moneyLeft,null) || ReferenceEquals(moneyRight,null))
+            {
+                return false;
+            }
             return moneyLeft.CompareTo(moneyRight) >= 0;
         }
 
         public static bool operator ==(BaseMoney moneyLeft, BaseMoney moneyRight)
         {
+            if (ReferenceEquals(moneyLeft, moneyRight))
+            {
+                return true;
+            }
+            if (ReferenceEquals(moneyLeft,null) || ReferenceEquals(moneyRight,null))
+            {
+                return false;
+            }
             return moneyLeft.CompareTo(moneyRight) == 0;
         }
 
         public static bool operator !=(BaseMoney moneyLeft, BaseMoney moneyRight)
         {
+            if (ReferenceEquals(moneyLeft, moneyRight))
+            {
+                return false;
+            }
+            if (ReferenceEquals(moneyLeft,null) || ReferenceEquals(moneyRight,null))
+            {
+                return true;
+            }
             return moneyLeft.CompareTo(moneyRight) != 0;
         }
 
         public override bool Equals(object obj)
         {
-            if (!(obj is BaseMoney money))
+            if (ReferenceEquals(this, obj))
             {
-                throw new ArgumentException();
+                return true;
             }
-            if (this.CurrencyCode != money.CurrencyCode)
+            if (ReferenceEquals(obj,null) || ReferenceEquals(this,null))
+            {
+                return false;
+            }
+            if (!(obj is BaseMoney money))
             {
                 throw new ArgumentException();
             }