src/HotChocolate/Core/src/Types/Types/Scalars/UuidType.cs

@@ -1,5 +1,7 @@
 using System;
 using System.Buffers.Text;
+using System.Linq;
+using System.Text;
 using HotChocolate.Language;
 using HotChocolate.Properties;
 
@@ -85,12 +87,17 @@ public UuidType(
 
         protected override bool IsInstanceOfType(StringValueNode valueSyntax)
         {
-            if (Utf8Parser.TryParse(valueSyntax.AsSpan(), out Guid _, out _, _format[0]))
+            if (_enforceFormat)
             {
-                return true;
-            }
+                ReadOnlySpan<byte> value = valueSyntax.AsSpan();
 
-            if (!_enforceFormat && Guid.TryParse(valueSyntax.Value, out _))
+                if (Utf8Parser.TryParse(value, out Guid _, out var consumed, _format[0]) &&
+                    consumed == value.Length)
+                {
+                    return true;
+                }
+            }
+            else if(Guid.TryParse(valueSyntax.Value, out _))
             {
                 return true;
             }
@@ -100,12 +107,17 @@ protected override bool IsInstanceOfType(StringValueNode valueSyntax)
 
         protected override Guid ParseLiteral(StringValueNode valueSyntax)
         {
-            if (Utf8Parser.TryParse(valueSyntax.AsSpan(), out Guid g, out _, _format[0]))
+            if (_enforceFormat)
             {
-                return g;
-            }
+                ReadOnlySpan<byte> value = valueSyntax.AsSpan();
 
-            if (!_enforceFormat && Guid.TryParse(valueSyntax.Value, out g))
+                if (Utf8Parser.TryParse(value, out Guid g, out var consumed, _format[0]) &&
+                    consumed == value.Length)
+                {
+                    return g;
+                }
+            }
+            else if(Guid.TryParse(valueSyntax.Value, out Guid g))
             {
                 return g;
             }
@@ -168,10 +180,23 @@ public override bool TryDeserialize(object? resultValue, out object? runtimeValu
                 return true;
             }
 
-            if (resultValue is string s && Guid.TryParse(s, out Guid guid))
+            if (resultValue is string s)
             {
-                runtimeValue = guid;
-                return true;
+                byte[] bytes = Encoding.UTF8.GetBytes(s);
+
+                if (_enforceFormat &&
+                    Utf8Parser.TryParse(bytes, out Guid guid, out var consumed, _format[0]) &&
+                    consumed == bytes.Length)
+                {
+                    runtimeValue = guid;
+                    return true;
+                }
+
+                if (!_enforceFormat && Guid.TryParse(s, out guid))
+                {
+                    runtimeValue = guid;
+                    return true;
+                }
             }
 
             if (resultValue is Guid)

src/HotChocolate/Core/test/Types.Tests/Types/Scalars/UuidTypeTests.cs

@@ -86,7 +86,7 @@ public void Serialize_Null()
             var uuidType = new UuidType();
 
             // act
-            object? serializedValue = uuidType.Serialize(null);
+            var serializedValue = uuidType.Serialize(null);
 
             // assert
             Assert.Null(serializedValue);
@@ -113,7 +113,7 @@ public void Deserialize_Null()
             var uuidType = new UuidType();
 
             // act
-            var success = uuidType.TryDeserialize(null, out object? o);
+            var success = uuidType.TryDeserialize(null, out var o);
 
             // assert
             Assert.True(success);
@@ -128,7 +128,7 @@ public void Deserialize_String()
             var guid = Guid.NewGuid();
 
             // act
-            var success = uuidType.TryDeserialize(guid.ToString("N"), out object? o);
+            var success = uuidType.TryDeserialize(guid.ToString("N"), out var o);
 
             // assert
             Assert.True(success);
@@ -143,7 +143,7 @@ public void Deserialize_Guid()
             var guid = Guid.NewGuid();
 
             // act
-            var success = uuidType.TryDeserialize(guid, out object? o);
+            var success = uuidType.TryDeserialize(guid, out var o);
 
             // assert
             Assert.True(success);
@@ -219,7 +219,7 @@ public void ParseLiteral_NullValueNode()
             NullValueNode literal = NullValueNode.Default;
 
             // act
-            object? value = uuidType.ParseLiteral(literal);
+            var value = uuidType.ParseLiteral(literal);
 
             // assert
             Assert.Null(value);
@@ -283,7 +283,7 @@ public void ParseValue_Int()
         }
 
         [Fact]
-        public void EnsureDateTypeKindIsCorret()
+        public void EnsureDateTypeKindIsCorrect()
         {
             // arrange
             var type = new UuidType();
@@ -374,12 +374,108 @@ public void Specify_Invalid_Format()
             void Action() => new UuidType(defaultFormat: 'z');
 
             // assert
-            #if NETCOREAPP2_1
+#if NETCOREAPP2_1
             Assert.Throws<ArgumentException>(Action).Message
                 .MatchSnapshot(new SnapshotNameExtension("NETCOREAPP2_1"));
-            #else
+#else
             Assert.Throws<ArgumentException>(Action).Message.MatchSnapshot();
-            #endif
+#endif
+        }
+
+        [InlineData(false)]
+        [InlineData(true)]
+        [Theory]
+        public void Parse_Guid_String_With_Appended_String(bool enforceFormat)
+        {
+            // arrange
+            var input = new StringValueNode("fbdef721-93c5-4267-8f92-ca27b60aa51f-foobar");
+            var uuidType = new UuidType(defaultFormat: 'D', enforceFormat: enforceFormat);
+
+            // act
+            void Fail() => uuidType.ParseLiteral(input);
+
+            // assert
+            Assert.Throws<SerializationException>(Fail);
+        }
+
+        [InlineData(false)]
+        [InlineData(true)]
+        [Theory]
+        public void Parse_Guid_Valid_Input(bool enforceFormat)
+        {
+            // arrange
+            var input = new StringValueNode("fbdef721-93c5-4267-8f92-ca27b60aa51f");
+            var uuidType = new UuidType(defaultFormat: 'D', enforceFormat: enforceFormat);
+
+            // act
+            var guid = (Guid)uuidType.ParseLiteral(input)!;
+
+            // assert
+            Assert.Equal(input.Value, guid.ToString("D"));
+        }
+
+        [InlineData(false)]
+        [InlineData(true)]
+        [Theory]
+        public void Deserialize_Guid_String_With_Appended_String(bool enforceFormat)
+        {
+            // arrange
+            var input = "fbdef721-93c5-4267-8f92-ca27b60aa51f-foobar";
+            var uuidType = new UuidType(defaultFormat: 'D', enforceFormat: enforceFormat);
+
+            // act
+            void Fail() => uuidType.Deserialize(input);
+
+            // assert
+            Assert.Throws<SerializationException>(Fail);
+        }
+
+        [InlineData(false)]
+        [InlineData(true)]
+        [Theory]
+        public void Deserialize_Guid_Valid_Format(bool enforceFormat)
+        {
+            // arrange
+            var input = "fbdef721-93c5-4267-8f92-ca27b60aa51f";
+            var uuidType = new UuidType(defaultFormat: 'D', enforceFormat: enforceFormat);
+
+            // act
+            var guid = (Guid)uuidType.Deserialize(input)!;
+
+            // assert
+            Assert.Equal(input, guid.ToString("D"));
+        }
+
+        [InlineData(false)]
+        [InlineData(true)]
+        [Theory]
+        public void IsInstanceOf_Guid_String_With_Appended_String(bool enforceFormat)
+        {
+            // arrange
+            var input = new StringValueNode("fbdef721-93c5-4267-8f92-ca27b60aa51f-foobar");
+            var uuidType = new UuidType(defaultFormat: 'D', enforceFormat: enforceFormat);
+
+            // act
+            var result = uuidType.IsInstanceOfType(input);
+
+            // assert
+            Assert.False(result);
+        }
+
+        [InlineData(false)]
+        [InlineData(true)]
+        [Theory]
+        public void IsInstanceOf_Guid_Valid_Format(bool enforceFormat)
+        {
+            // arrange
+            var input = new StringValueNode("fbdef721-93c5-4267-8f92-ca27b60aa51f");
+            var uuidType = new UuidType(defaultFormat: 'D', enforceFormat: enforceFormat);
+
+            // act
+            var result = uuidType.IsInstanceOfType(input);
+
+            // assert
+            Assert.True(result);
         }
     }
 }