Adds Refactor to Equals in Path String, Adds Regression Tests

Author: Justin Kotalik

src/Microsoft.AspNetCore.Http.Abstractions/PathString.cs

@@ -213,7 +213,7 @@ public string Add(QueryString other)
         /// <returns>True if both PathString values are equal</returns>
         public bool Equals(PathString other)
         {
-            return string.Equals(_value, other._value, StringComparison.OrdinalIgnoreCase);
+            return Equals(other, StringComparison.OrdinalIgnoreCase);
         }
 
         /// <summary>
@@ -224,6 +224,10 @@ public bool Equals(PathString other)
         /// <returns>True if both PathString values are equal</returns>
         public bool Equals(PathString other, StringComparison comparisonType)
         {
+            if (!HasValue && !other.HasValue)
+            {
+                return true;
+            }
             return string.Equals(_value, other._value, comparisonType);
         }
 
@@ -236,9 +240,9 @@ public override bool Equals(object obj)
         {
             if (ReferenceEquals(null, obj))
             {
-                return false;
+                return !HasValue;
             }
-            return obj is PathString && Equals((PathString)obj, StringComparison.OrdinalIgnoreCase);
+            return obj is PathString && Equals((PathString)obj);
         }
 
         /// <summary>
@@ -247,7 +251,7 @@ public override bool Equals(object obj)
         /// <returns>The hash code</returns>
         public override int GetHashCode()
         {
-            return (_value != null ? StringComparer.OrdinalIgnoreCase.GetHashCode(_value) : 0);
+            return (HasValue ? StringComparer.OrdinalIgnoreCase.GetHashCode(_value) : 0);
         }
 
         /// <summary>
@@ -258,7 +262,7 @@ public override int GetHashCode()
         /// <returns>True if both PathString values are equal</returns>
         public static bool operator ==(PathString left, PathString right)
         {
-            return left.Equals(right, StringComparison.OrdinalIgnoreCase);
+            return left.Equals(right);
         }
 
         /// <summary>
@@ -269,7 +273,7 @@ public override int GetHashCode()
         /// <returns>True if both PathString values are not equal</returns>
         public static bool operator !=(PathString left, PathString right)
         {
-            return !left.Equals(right, StringComparison.OrdinalIgnoreCase);
+            return !left.Equals(right);
         }
 
         /// <summary>

test/Microsoft.AspNetCore.Http.Abstractions.Tests/PathStringTests.cs

@@ -16,6 +16,44 @@ public void CtorThrows_IfPathDoesNotHaveLeadingSlash()
             ExceptionAssert.ThrowsArgument(() => new PathString("hello"), "value", "The path in 'value' must start with '/'.");
         }
 
+        [Fact]
+        public void Equals_EmptyPathStringAndDefaultPathString()
+        {
+            // Act and Assert
+            Assert.Equal(PathString.Empty, default(PathString));
+            Assert.Equal(default(PathString), PathString.Empty);
+            Assert.True(PathString.Empty == default(PathString));
+            Assert.True(default(PathString) == PathString.Empty);
+            Assert.True(PathString.Empty.Equals(default(PathString)));
+            Assert.True(default(PathString).Equals(PathString.Empty));
+        }
+
+        [Fact]
+        public void NotEquals_DefaultPathStringAndNonNullPathString()
+        {
+            // Arrange
+            var pathString = new PathString("/hello");
+
+            // Act and Assert
+            Assert.NotEqual(pathString, default(PathString));
+        }
+
+        [Fact]
+        public void NotEquals_EmptyPathStringAndNonNullPathString()
+        {
+            // Arrange
+            var pathString = new PathString("/hello");
+
+            // Act and Assert
+            Assert.NotEqual(pathString, PathString.Empty);
+        }
+
+        [Fact]
+        public void HashCode_CheckNullAndEmptyHaveSameHashcodes()
+        {
+            Assert.Equal(PathString.Empty.GetHashCode(), default(PathString).GetHashCode());
+        }
+
         [Theory]
         [InlineData(null, null)]
         [InlineData("", null)]