AutoMapProperty/AutoMapProperty.Tests/MappingRegressionTests.cs

using Microsoft.CodeAnalysis;
using Xunit;

namespace AutoMapProperty.Tests;

public class MappingRegressionTests
{
    [Fact]
    public void NullableNestedDtosMapNullAndNonNullValues()
    {
        var compilation = new GeneratorTestCompilation("""
            namespace Fixtures
            {
                public class Child
                {
                    [AutoMapProperty("Response")]
                    public int Value { get; set; }
                }
                public class Parent
                {
                    [AutoMapProperty("Response", typeof(ChildResponse), Nullability = AutoMapNullability.Nullable)]
                    public Child Child { get; set; } = new Child();
                }
                public static class Check
                {
                    public static bool Run()
                    {
                        var parent = new Parent { Child = new Child { Value = 42 } };
                        var dto = new ParentResponse().ApplyFrom(null, parent);
                        if (dto.Child.Value != 42 || dto.GetProjectorFrom(null).Compile()(parent).Child.Value != 42)
                            return false;
                        dto.Child = null;
                        dto.ApplyTo(null, parent);
                        if (parent.Child != null || new ParentResponse().ApplyFrom(null, parent).Child != null ||
                            dto.GetProjectorFrom(null).Compile()(parent).Child != null)
                            return false;
                        if (!ParentResponse.EqualExpression(null, parent).Compile()(dto) ||
                            !dto.Equals(new ParentResponse { Child = null }))
                            return false;
                        dto.Child = new ChildResponse { Value = 17 };
                        dto.ApplyTo(null, parent);
                        return parent.Child.Value == 17;
                    }
                }
            }
            """);
        Assert.Equal(NullableAnnotation.Annotated, compilation.Property("Fixtures.ParentResponse", "Child").Type.NullableAnnotation);
        Assert.Equal(true, compilation.Evaluate());
    }

    [Fact]
    public void InheritedGeneratedPropertiesParticipateInMappings()
    {
        var compilation = new GeneratorTestCompilation("""
            namespace Fixtures
            {
                public class Base
                {
                    [AutoMapProperty("Request", Nullability = AutoMapNullability.NonNullable)]
                    public string? Name { get; set; }
                }
                public class Derived : Base
                {
                    [AutoMapProperty("Request")]
                    public int Value { get; set; }
                }
                public partial class DerivedRequest : BaseRequest { }
                public static class Check
                {
                    public static bool Run()
                    {
                        var entity = new Derived { Name = "name", Value = 42 };
                        var dto = new DerivedRequest().ApplyFrom(null, entity);
                        var projected = dto.GetProjectorFrom(null).Compile()(entity);
                        dto.Name = "changed";
                        dto.ApplyTo(null, entity);
                        return entity.Name == "changed" && projected.Name == "name" && projected.Value == 42;
                    }
                }
            }
            """);
        Assert.Equal(true, compilation.Evaluate());
    }

    [Fact]
    public void CustomConvertersReceiveOverriddenNullableValues()
    {
        var compilation = new GeneratorTestCompilation("""
            namespace Fixtures
            {
                public class Entity
                {
                    [AutoMapProperty("Request", typeof(string), nameof(Parse), nameof(Format), Nullability = AutoMapNullability.Nullable)]
                    public int Value { get; set; }
                    public static int Parse(IServiceProvider providers, Entity entity, string? value) => value == null ? 0 : int.Parse(value);
                    public static string Format(IServiceProvider providers, Entity entity, int value) => value.ToString();
                }
                public static class Check
                {
                    public static bool Run()
                    {
                        var entity = new Entity { Value = 42 };
                        var dto = new EntityRequest().ApplyFrom(null, entity);
                        if (dto.Value != "42" || dto.GetProjectorFrom(null).Compile()(entity).Value != "42")
                            return false;
                        dto.Value = null;
                        dto.ApplyTo(null, entity);
                        return entity.Value == 0;
                    }
                }
            }
            """);
        Assert.Equal(true, compilation.Evaluate());
    }

    [Fact]
    public void FiltersMappingAttributesFromSharedListsAndKeepsValidationAttributes()
    {
        var compilation = new GeneratorTestCompilation("""
            namespace Fixtures
            {
                public class Entity
                {
                    [System.ComponentModel.DataAnnotations.Required, AutoMapProperty("Response", Nullability = AutoMapNullability.Nullable)]
                    public string Value { get; set; } = "initial";
                }
            }
            """);
        compilation.AssertCompiles();
        var attribute = Assert.Single(compilation.Property("Fixtures.EntityResponse", "Value").GetAttributes());
        Assert.Equal("RequiredAttribute", attribute.AttributeClass!.Name);
    }

    [Fact]
    public void NestedCollectionsAndArrayTypeReplacementsKeepMappingAndInitializerBehavior()
    {
        var compilation = new GeneratorTestCompilation("""
            namespace Fixtures
            {
                public class Child
                {
                    [AutoMapProperty("Response")]
                    public int Value { get; set; }
                }
                public class Parent
                {
                    [AutoMapProperty("Response", typeof(ChildResponse[]), Nullability = AutoMapNullability.Nullable)]
                    public Child[] Children { get; set; } = Array.Empty<Child>();
                }
                public static class Check
                {
                    public static bool Run()
                    {
                        var parent = new Parent { Children = new[] { new Child { Value = 42 } } };
                        var dto = new ParentResponse().ApplyFrom(null, parent);
                        if (dto.Children[0].Value != 42 || dto.GetProjectorFrom(null).Compile()(parent).Children[0].Value != 42)
                            return false;
                        dto.Children[0].Value = 17;
                        dto.ApplyTo(null, parent);
                        if (parent.Children[0].Value != 17)
                            return false;
                        dto.Children = null;
                        dto.ApplyTo(null, parent);
                        return parent.Children.Length == 0;
                    }
                }
            }
            """);
        Assert.Equal(true, compilation.Evaluate());
    }

    [Fact]
    public void SupportsInterfacesComputedPropertiesAndNullTypeArguments()
    {
        var compilation = new GeneratorTestCompilation("""
            namespace Fixtures
            {
                public interface ISource
                {
                    [AutoMapProperty("Request", Nullability = AutoMapNullability.Nullable)]
                    string Name { get; }
                }
                public class Entity
                {
                    [AutoMapProperty("Response", null, Nullability = AutoMapNullability.NonNullable)]
                    public string? Name => "name";
                }
                public static class Check
                {
                    public static bool Run() => new EntityResponse().ApplyFrom(null, new Entity()).Name == "name";
                }
            }
            """);
        Assert.Equal(NullableAnnotation.Annotated, compilation.Property("Fixtures.ISourceRequest", "Name").Type.NullableAnnotation);
        Assert.Equal(NullableAnnotation.NotAnnotated, compilation.Property("Fixtures.EntityResponse", "Name").Type.NullableAnnotation);
        Assert.Equal(true, compilation.Evaluate());
    }
}