GraphQL - custom scalar support (#1012)

* x

* CustomScalars

* more tests

* .

* add or set

* ...

* x

test/WireMock.Net.Tests/Matchers/GraphQLMatcherTests.cs

@@ -1,7 +1,10 @@
 #if GRAPHQL
 using System;
+using System.Collections.Generic;
+using CSScripting;
 using FluentAssertions;
 using GraphQLParser.Exceptions;
+using WireMock.Exceptions;
 using WireMock.Matchers;
 using WireMock.Models;
 using Xunit;
@@ -99,6 +102,62 @@ public class GraphQLMatcherTests
         matcher.GetPatterns().Should().Contain(TestSchema);
     }
 
+    [Fact]
+    public void GraphQLMatcher_For_ValidSchema_And_CorrectGraphQL_UsingCustomType_Mutation_IsMatch()
+    {
+        // Arrange
+        const string testSchema = @"
+  scalar DateTime
+  scalar MyCustomScalar
+
+  type Message {
+    id: ID!
+  }
+
+  type Mutation {
+    createMessage(x: MyCustomScalar, dt: DateTime): Message
+  }";
+
+        var input = @"{
+    ""query"": ""mutation CreateMessage($x: MyCustomScalar!, $dt: DateTime!) { createMessage(x: $x, dt: $dt) { id } }"",
+    ""variables"": { ""x"": 100, ""dt"": ""2007-12-03T10:15:30Z"" }
+}";
+
+        var customScalars = new Dictionary<string, Type> { { "MyCustomScalar", typeof(int) } };
+
+        // Act
+        var matcher = new GraphQLMatcher(testSchema, customScalars);
+        var result = matcher.IsMatch(input);
+
+        // Assert
+        result.Score.Should().Be(MatchScores.Perfect);
+
+        matcher.GetPatterns().Should().Contain(testSchema);
+    }
+
+    [Fact]
+    public void GraphQLMatcher_For_ValidSchema_And_CorrectGraphQL_UsingCustomType_But_NoDefinedCustomScalars_Mutation_IsNoMatch()
+    {
+        // Arrange
+        const string testSchema = @"
+  scalar DateTime
+  scalar MyCustomScalar
+
+  type Message {
+    id: ID!
+  }
+
+  type Mutation {
+    createMessage(x: MyCustomScalar, dt: DateTime): Message
+  }";
+
+        // Act
+        Action action = () => _ = new GraphQLMatcher(testSchema);
+
+        // Assert
+        action.Should().Throw<WireMockException>().WithMessage("The GraphQL Scalar type 'MyCustomScalar' is not defined in the CustomScalars dictionary.");
+    }
+
     [Fact]
     public void GraphQLMatcher_For_ValidSchema_And_IncorrectQuery_IsMismatch()
     {