Allow selector to be null when using Select.

src/GreenDonut/src/Core/Projections/SelectionDataLoaderExtensions.cs

@@ -32,9 +32,9 @@ public static class SelectionDataLoaderExtensions
     /// <exception cref="ArgumentNullException">
     /// Throws if <paramref name="dataLoader"/> is <c>null</c>.
     /// </exception>
-    public static ISelectionDataLoader<TKey, TValue> Select<TKey, TValue>(
+    public static IDataLoader<TKey, TValue> Select<TKey, TValue>(
         this IDataLoader<TKey, TValue> dataLoader,
-        Expression<Func<TValue, TValue>> selector)
+        Expression<Func<TValue, TValue>>? selector)
         where TKey : notnull
     {
         if (dataLoader is null)
@@ -44,7 +44,14 @@ public static ISelectionDataLoader<TKey, TValue> Select<TKey, TValue>(
 
         if (selector is null)
         {
-            throw new ArgumentNullException(nameof(selector));
+            return dataLoader;
+        }
+
+        if (dataLoader is ISelectionDataLoader<TKey, TValue>)
+        {
+            var context = (DefaultSelectorBuilder<TValue>)dataLoader.ContextData[typeof(ISelectorBuilder).FullName!]!;
+            context.Add(selector);
+            return dataLoader;
         }
 
         var branchKey = selector.ToString();
@@ -65,48 +72,6 @@ static IDataLoader CreateBranch(
         }
     }
 
-    /// <summary>
-    /// Adds another selector to the branched DataLoader.
-    /// </summary>
-    /// <param name="dataLoader">
-    /// The branched DataLoader.
-    /// </param>
-    /// <param name="selector">
-    /// The data selector.
-    /// </param>
-    /// <typeparam name="TKey">
-    /// The key type.
-    /// </typeparam>
-    /// <typeparam name="TValue">
-    /// The value type.
-    /// </typeparam>
-    /// <returns>
-    /// Returns the branched DataLoader with the selector applied.
-    /// </returns>
-    /// <exception cref="ArgumentNullException">
-    /// Throws if <paramref name="dataLoader"/> is <c>null</c>.
-    /// </exception>
-    public static ISelectionDataLoader<TKey, TValue> Select<TKey, TValue>(
-        this ISelectionDataLoader<TKey, TValue> dataLoader,
-        Expression<Func<TValue, TValue>> selector)
-        where TKey : notnull
-    {
-        if (dataLoader is null)
-        {
-            throw new ArgumentNullException(nameof(dataLoader));
-        }
-
-        if (selector is null)
-        {
-            throw new ArgumentNullException(nameof(selector));
-        }
-
-        var context = (DefaultSelectorBuilder<TValue>)dataLoader.ContextData[typeof(ISelectorBuilder).FullName!]!;
-        context.Add(selector);
-        return dataLoader;
-    }
-
-    /*
     /// <summary>
     /// Includes a property in the query.
     /// </summary>
@@ -161,54 +126,9 @@ public static IDataLoader<TKey, TValue> Include<TKey, TValue>(
                 nameof(includeSelector));
         }
 
-        DefaultSelectorBuilder<TValue> context;
-        if (dataLoader.ContextData.TryGetValue(typeof(ISelectorBuilder).FullName!, out var value)
-            && value is DefaultSelectorBuilder<TValue> casted)
-        {
-            context = casted;
-        }
-        else
-        {
-            context = new DefaultSelectorBuilder<TValue>();
-        }
-
-        context.Add(ExpressionHelpers.Rewrite(includeSelector));
-        dataLoader.ContextData = dataLoader.ContextData.SetItem(typeof(ISelectorBuilder).FullName!, context);
-        return dataLoader;
-    }
-    */
-
-    public static ISelectionDataLoader<TKey, TValue> Include<TKey, TValue>(
-        this ISelectionDataLoader<TKey, TValue> dataLoader,
-        Expression<Func<TValue, object?>> includeSelector)
-        where TKey : notnull
-    {
-        if (dataLoader is null)
-        {
-            throw new ArgumentNullException(nameof(dataLoader));
-        }
-
-        if (includeSelector is null)
-        {
-            throw new ArgumentNullException(nameof(includeSelector));
-        }
-
-        if (includeSelector is not LambdaExpression lambda)
-        {
-            throw new ArgumentException(
-                "The include selector must be a lambda expression.",
-                nameof(includeSelector));
-        }
-
-        if (lambda.Body is not MemberExpression member
-            || member.Member.MemberType != MemberTypes.Property)
-        {
-            throw new ArgumentException(
-                "The include selector must be a property selector.",
-                nameof(includeSelector));
-        }
-
-        var context = (DefaultSelectorBuilder<TValue>)dataLoader.ContextData[typeof(ISelectorBuilder).FullName!]!;
+        var context = dataLoader.GetOrSetState(
+            typeof(ISelectorBuilder).FullName!,
+            _ => new DefaultSelectorBuilder<TValue>());
         context.Add(Rewrite(includeSelector));
         return dataLoader;
     }

src/HotChocolate/Core/src/Execution/Projections/HotChocolateExecutionDataLoaderExtensions.cs

@@ -29,7 +29,7 @@ public static class HotChocolateExecutionDataLoaderExtensions
     /// <returns>
     /// Returns a new data loader that applies the selection.
     /// </returns>
-    public static ISelectionDataLoader<TKey, TValue> Select<TKey, TValue>(
+    public static IDataLoader<TKey, TValue> Select<TKey, TValue>(
         this IDataLoader<TKey, TValue> dataLoader,
         ISelection selection)
         where TKey : notnull

src/HotChocolate/Core/src/Types/Types/Descriptors/Contracts/IObjectFieldDescriptor.cs

@@ -319,4 +319,26 @@ IObjectFieldDescriptor Directive<T>()
     /// <param name="arguments">The arguments of the directive</param>
     /// <returns>The descriptor</returns>
     IObjectFieldDescriptor Directive(string name, params ArgumentNode[] arguments);
+
+    /// <summary>
+    /// Specifies the requirements for the parent object.
+    /// </summary>
+    /// <param name="requires">
+    /// The requirements for the parent object.
+    /// </param>
+    /// <returns>
+    /// Returns the descriptor to chain further configuration.
+    /// </returns>
+    IObjectFieldDescriptor ParentRequires<TParent>(string? requires);
+
+    /// <summary>
+    /// Specifies the requirements for the parent object.
+    /// </summary>
+    /// <param name="requires">
+    /// The requirements for the parent object.
+    /// </param>
+    /// <returns>
+    /// Returns the descriptor to chain further configuration.
+    /// </returns>
+    IObjectFieldDescriptor ParentRequires(string? requires);
 }

src/HotChocolate/Core/src/Types/Types/Descriptors/ObjectFieldDescriptor.cs

@@ -472,6 +472,39 @@ public IObjectFieldDescriptor Use(FieldMiddleware middleware)
         return this;
     }
 
+    /// <inheritdoc />
+    public IObjectFieldDescriptor ParentRequires<TParent>(string? requires)
+    {
+        if (!(requires?.Length > 0))
+        {
+            Definition.Flags &= ~FieldFlags.WithRequirements;
+            Definition.ContextData.Remove(FieldRequirementsSyntax);
+            Definition.ContextData.Remove(FieldRequirementsEntity);
+            return this;
+        }
+
+        Definition.Flags |= FieldFlags.WithRequirements;
+        Definition.ContextData[FieldRequirementsSyntax] = requires;
+        Definition.ContextData[FieldRequirementsEntity] = typeof(TParent);
+        return this;
+    }
+
+    public IObjectFieldDescriptor ParentRequires(string? requires)
+    {
+        if (!(requires?.Length > 0))
+        {
+            Definition.Flags &= ~FieldFlags.WithRequirements;
+            Definition.ContextData.Remove(FieldRequirementsSyntax);
+            Definition.ContextData.Remove(FieldRequirementsEntity);
+            return this;
+        }
+
+        Definition.Flags |= FieldFlags.WithRequirements;
+        Definition.ContextData[FieldRequirementsSyntax] = requires;
+        Definition.ContextData[FieldRequirementsEntity] = Definition.SourceType;
+        return this;
+    }
+
     /// <summary>
     /// Creates a new instance of <see cref="ObjectFieldDescriptor"/>
     /// </summary>

src/HotChocolate/Core/test/Execution.Tests/Projections/ProjectableDataLoaderTests.cs

@@ -1,3 +1,4 @@
+using System.Linq.Expressions;
 using CookieCrumble;
 using GreenDonut;
 using GreenDonut.Projections;
@@ -49,6 +50,37 @@ public async Task Brand_With_Name()
             .MatchMarkdownSnapshot();
     }
 
+    [Fact]
+    public async Task Brand_With_Name_Selector_is_Null()
+    {
+        // Arrange
+        var queries = new List<string>();
+        var connectionString = CreateConnectionString();
+        await CatalogContext.SeedAsync(connectionString);
+
+        // Act
+        var result = await new ServiceCollection()
+            .AddScoped(_ => queries)
+            .AddTransient(_ => new CatalogContext(connectionString))
+            .AddGraphQL()
+            .AddQueryType<Query>()
+            .AddPagingArguments()
+            .ModifyRequestOptions(o => o.IncludeExceptionDetails = true)
+            .ExecuteRequestAsync(
+                """
+                {
+                    brandByIdSelectorNull(id: 1) {
+                        name
+                    }
+                }
+                """);
+
+        Snapshot.Create()
+            .AddSql(queries)
+            .AddResult(result)
+            .MatchMarkdownSnapshot();
+    }
+
     [Fact]
     public async Task Manual_Include_Of_Brand()
     {
@@ -399,6 +431,70 @@ public async Task Brand_Details_Requires_Brand_Name()
             .MatchMarkdownSnapshot();
     }
 
+    [Fact]
+    public async Task Brand_Details_Requires_Brand_Name_With_Proper_Type()
+    {
+        // Arrange
+        var queries = new List<string>();
+        var connectionString = CreateConnectionString();
+        await CatalogContext.SeedAsync(connectionString);
+
+        // Act
+        var result = await new ServiceCollection()
+            .AddScoped(_ => queries)
+            .AddTransient(_ => new CatalogContext(connectionString))
+            .AddGraphQL()
+            .AddQueryType<Query>()
+            .AddType<BrandWithRequirementType>()
+            .AddPagingArguments()
+            .ModifyRequestOptions(o => o.IncludeExceptionDetails = true)
+            .ExecuteRequestAsync(
+                """
+                {
+                    brandById(id: 1) {
+                        details
+                    }
+                }
+                """);
+
+        Snapshot.Create()
+            .AddSql(queries)
+            .AddResult(result)
+            .MatchMarkdownSnapshot();
+    }
+
+    [Fact]
+    public async Task Brand_Details_Requires_Brand_Name_With_Proper_Type_With_Explicit_Generic()
+    {
+        // Arrange
+        var queries = new List<string>();
+        var connectionString = CreateConnectionString();
+        await CatalogContext.SeedAsync(connectionString);
+
+        // Act
+        var result = await new ServiceCollection()
+            .AddScoped(_ => queries)
+            .AddTransient(_ => new CatalogContext(connectionString))
+            .AddGraphQL()
+            .AddQueryType<Query>()
+            .AddType<BrandWithRequirementTypeWithGeneric>()
+            .AddPagingArguments()
+            .ModifyRequestOptions(o => o.IncludeExceptionDetails = true)
+            .ExecuteRequestAsync(
+                """
+                {
+                    brandById(id: 1) {
+                        details
+                    }
+                }
+                """);
+
+        Snapshot.Create()
+            .AddSql(queries)
+            .AddResult(result)
+            .MatchMarkdownSnapshot();
+    }
+
     [Fact]
     public async Task Brand_Details_Requires_Brand_Name_2()
     {
@@ -460,7 +556,7 @@ public async Task Brand_Products_TypeName()
                 """);
 
         // at the moment we do not support projections on lists
-        // so products will be empty and we will just select the brand.Id
+        // so products will be empty, and we will just select the brand.Id
         Snapshot.Create()
             .AddSql(queries)
             .AddResult(result)
@@ -529,14 +625,18 @@ public class Query
             CancellationToken cancellationToken)
             => await productById.Select(selection).Include(c => c.Brand).LoadAsync(id, cancellationToken);
 
-        /*
         public async Task<Product?> GetProductByIdWithBrandNoSelectionAsync(
             int id,
             ISelection selection,
             ProductByIdDataLoader productById,
             CancellationToken cancellationToken)
             => await productById.Include(c => c.Brand).LoadAsync(id, cancellationToken);
-            */
+
+        public async Task<Brand?> GetBrandByIdSelectorNullAsync(
+            int id,
+            BrandByIdDataLoader brandById,
+            CancellationToken cancellationToken)
+            => await brandById.Select(default(Expression<Func<Brand, Brand>>)).LoadAsync(id, cancellationToken);
     }
 
     [ExtendObjectType<Brand>]
@@ -557,6 +657,28 @@ public string GetDetails(
             => "Brand Name:" + brand.Name;
     }
 
+    public class BrandWithRequirementType : ObjectType<Brand>
+    {
+        protected override void Configure(IObjectTypeDescriptor<Brand> descriptor)
+        {
+            descriptor
+                .Field(t => t.Details)
+                .ParentRequires(nameof(Brand.Name))
+                .Resolve(ctx => "Brand Name:" + ctx.Parent<Brand>().Name);
+        }
+    }
+
+    public class BrandWithRequirementTypeWithGeneric : ObjectType<Brand>
+    {
+        protected override void Configure(IObjectTypeDescriptor<Brand> descriptor)
+        {
+            descriptor
+                .Field(t => t.Details)
+                .ParentRequires<Brand>(nameof(Brand.Name))
+                .Resolve(ctx => "Brand Name:" + ctx.Parent<Brand>().Name);
+        }
+    }
+
     [ExtendObjectType<Product>]
     public class ProductExtensions
     {