GraphQL - custom scalar support (#1012)

* x

* CustomScalars

* more tests

* .

* add or set

* ...

* x

test/WireMock.Net.Tests/Matchers/Models/WireMockCustomScalarGraphTypeTests.cs

@@ -0,0 +1,96 @@
+#if GRAPHQL
+using System;
+using FluentAssertions;
+using WireMock.Matchers.Models;
+using Xunit;
+
+namespace WireMock.Net.Tests.Matchers.Models;
+
+public class WireMockCustomScalarGraphTypeTests
+{
+    private class MyIntScalarGraphType : WireMockCustomScalarGraphType<int> { }
+
+    private class MyStringScalarGraphType : WireMockCustomScalarGraphType<string> { }
+
+    [Fact]
+    public void ParseValue_ShouldReturnNull_When_ValueIsNull()
+    {
+        // Arrange
+        var intGraphType = new MyIntScalarGraphType();
+
+        // Act
+        var result = intGraphType.ParseValue(null);
+
+        // Assert
+        result.Should().BeNull();
+    }
+
+    [Fact]
+    public void ParseValue_ShouldReturnValue_When_ValueIsOfCorrectType()
+    {
+        // Arrange
+        var intGraphType = new MyIntScalarGraphType();
+
+        // Act
+        var result = intGraphType.ParseValue(5);
+
+        // Assert
+        result.Should().Be(5);
+    }
+
+    [Theory]
+    [InlineData("someString")]
+    [InlineData("100")]
+    public void ParseValue_ShouldThrowInvalidCastException_When_ValueIsStringAndTargetIsNotString(string stringValue)
+    {
+        // Arrange
+        var intGraphType = new MyIntScalarGraphType();
+
+        // Act
+        Action act = () => intGraphType.ParseValue(stringValue);
+
+        // Assert
+        act.Should().Throw<InvalidCastException>()
+           .WithMessage("Unable to convert value '*' of type 'System.String' to type 'System.Int32'.");
+    }
+
+    [Fact]
+    public void ParseValue_ShouldConvertValue_WhenTypeIsConvertible()
+    {
+        // Arrange
+        var intGraphType = new MyIntScalarGraphType();
+
+        // Act
+        var result = intGraphType.ParseValue(5L);
+
+        // Assert
+        result.Should().Be(5);
+    }
+
+    [Fact]
+    public void ParseValue_ShouldThrowException_When_ValueIsMaxLongAndTargetIsInt()
+    {
+        // Arrange
+        var intGraphType = new MyIntScalarGraphType();
+
+        // Act
+        Action act = () => intGraphType.ParseValue(long.MaxValue);
+
+        // Assert
+        act.Should().Throw<OverflowException>();
+    }
+
+    [Fact]
+    public void ParseValue_ShouldReturnStringValue_When_TypeIsString()
+    {
+        // Arrange
+        var stringGraphType = new MyStringScalarGraphType();
+
+        // Act
+        var result = stringGraphType.ParseValue("someString");
+
+        // Assert
+        result.Should().Be("someString");
+    }
+}
+#endif