Added mutation conventions.

src/HotChocolate/Core/HotChocolate.Core.sln

@@ -33,8 +33,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotChocolate.Subscriptions.
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotChocolate.Subscriptions.Redis", "src\Subscriptions.Redis\HotChocolate.Subscriptions.Redis.csproj", "{35C5F3EF-B192-4A07-B664-A3D360283907}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotChocolate.Types", "src\Types\HotChocolate.Types.csproj", "{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotChocolate.Validation", "src\Validation\HotChocolate.Validation.csproj", "{29FEE730-0D2C-4F31-934E-9BE2E9DC729A}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotChocolate.Abstractions.Tests", "test\Abstractions.Tests\HotChocolate.Abstractions.Tests.csproj", "{80F8703D-804D-4921-A409-AF4BB26E59BE}"
@@ -97,6 +95,12 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotChocolate.Types.NodaTime
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotChocolate.AspNetCore", "..\AspNetCore\src\AspNetCore\HotChocolate.AspNetCore.csproj", "{4AD904D1-7727-48EF-88D9-7B38D98EB314}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Types.Mutations", "src\Types.Mutations\Types.Mutations.csproj", "{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotChocolate.Types.Mutations", "src\Types.Mutations\HotChocolate.Types.Mutations.csproj", "{2B7E7416-E093-4763-B839-504CBFBC8F1C}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotChocolate.Types.Mutations.Tests", "test\Types.Mutations.Tests\HotChocolate.Types.Mutations.Tests.csproj", "{F6FFA925-8C49-4594-9FF2-8F571C2D6389}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -251,18 +255,6 @@ Global
 		{35C5F3EF-B192-4A07-B664-A3D360283907}.Release|x64.Build.0 = Release|Any CPU
 		{35C5F3EF-B192-4A07-B664-A3D360283907}.Release|x86.ActiveCfg = Release|Any CPU
 		{35C5F3EF-B192-4A07-B664-A3D360283907}.Release|x86.Build.0 = Release|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Debug|x64.Build.0 = Debug|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Debug|x86.Build.0 = Debug|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Release|Any CPU.Build.0 = Release|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Release|x64.ActiveCfg = Release|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Release|x64.Build.0 = Release|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Release|x86.ActiveCfg = Release|Any CPU
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63}.Release|x86.Build.0 = Release|Any CPU
 		{29FEE730-0D2C-4F31-934E-9BE2E9DC729A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{29FEE730-0D2C-4F31-934E-9BE2E9DC729A}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{29FEE730-0D2C-4F31-934E-9BE2E9DC729A}.Debug|x64.ActiveCfg = Debug|Any CPU
@@ -611,6 +603,42 @@ Global
 		{4AD904D1-7727-48EF-88D9-7B38D98EB314}.Release|x64.Build.0 = Release|Any CPU
 		{4AD904D1-7727-48EF-88D9-7B38D98EB314}.Release|x86.ActiveCfg = Release|Any CPU
 		{4AD904D1-7727-48EF-88D9-7B38D98EB314}.Release|x86.Build.0 = Release|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Debug|x64.Build.0 = Debug|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Debug|x86.Build.0 = Debug|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Release|x64.ActiveCfg = Release|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Release|x64.Build.0 = Release|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Release|x86.ActiveCfg = Release|Any CPU
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB}.Release|x86.Build.0 = Release|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Debug|x64.Build.0 = Debug|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Debug|x86.Build.0 = Debug|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Release|x64.ActiveCfg = Release|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Release|x64.Build.0 = Release|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Release|x86.ActiveCfg = Release|Any CPU
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C}.Release|x86.Build.0 = Release|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Debug|x64.Build.0 = Debug|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Debug|x86.Build.0 = Debug|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Release|x64.ActiveCfg = Release|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Release|x64.Build.0 = Release|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Release|x86.ActiveCfg = Release|Any CPU
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -628,7 +656,6 @@ Global
 		{350488E5-F800-4CBD-9278-1D5C84C78958} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
 		{CF768605-BAB8-42D8-A748-66791575BCFD} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
 		{35C5F3EF-B192-4A07-B664-A3D360283907} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
-		{1C16FAE5-16F7-4AAD-ABE5-4DA29D925F63} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
 		{29FEE730-0D2C-4F31-934E-9BE2E9DC729A} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
 		{80F8703D-804D-4921-A409-AF4BB26E59BE} = {7462D089-D350-44D6-8131-896D949A65B7}
 		{AADFF9B1-B275-48B4-8F32-F6CD837619E5} = {7462D089-D350-44D6-8131-896D949A65B7}
@@ -658,6 +685,9 @@ Global
 		{07F3E312-EC4C-4B71-A095-E478DF4CB52B} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
 		{414B6DBE-1A3A-42DC-9116-3F9A433C6BBB} = {7462D089-D350-44D6-8131-896D949A65B7}
 		{4AD904D1-7727-48EF-88D9-7B38D98EB314} = {7637D30E-7339-4D4E-9424-87CF2394D234}
+		{F3621170-A3D6-4BE7-9E16-E32BA9ABA1DB} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
+		{2B7E7416-E093-4763-B839-504CBFBC8F1C} = {37B9D3B1-CA34-4720-9A0B-CFF1E64F52C2}
+		{F6FFA925-8C49-4594-9FF2-8F571C2D6389} = {7462D089-D350-44D6-8131-896D949A65B7}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {E4D94C77-6657-4630-9D42-0A9AC5153A1B}

src/HotChocolate/Core/src/Core/HotChocolate.Core.csproj

@@ -11,13 +11,14 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\Subscriptions.InMemory\HotChocolate.Subscriptions.InMemory.csproj" />
     <ProjectReference Include="..\Types\HotChocolate.Types.csproj" />
-    <ProjectReference Include="..\Fetching\HotChocolate.Fetching.csproj" />
+    <ProjectReference Include="..\Types.Mutations\HotChocolate.Types.Mutations.csproj" />
     <ProjectReference Include="..\Types.CursorPagination\HotChocolate.Types.CursorPagination.csproj" />
     <ProjectReference Include="..\Types.OffsetPagination\HotChocolate.Types.OffsetPagination.csproj" />
     <ProjectReference Include="..\Validation\HotChocolate.Validation.csproj" />
+    <ProjectReference Include="..\Fetching\HotChocolate.Fetching.csproj" />
     <ProjectReference Include="..\Execution\HotChocolate.Execution.csproj" />
+    <ProjectReference Include="..\Subscriptions.InMemory\HotChocolate.Subscriptions.InMemory.csproj" />
   </ItemGroup>
 
   <PropertyGroup>

src/HotChocolate/Core/src/Types.Mutations/DependencyInjection/RequestExecutorBuilderExtensions.Errors.cs

@@ -0,0 +1,79 @@
+using HotChocolate.Execution.Configuration;
+
+namespace Microsoft.Extensions.DependencyInjection;
+
+public static class MutationRequestExecutorBuilderExtensions
+{
+    /// <summary>
+    /// Enables mutation conventions which will simplify creating GraphQL mutations.
+    /// </summary>
+    /// <param name="builder">
+    /// The request executor builder
+    /// </param>
+    /// <returns>
+    /// The request executor builder
+    /// </returns>
+    /// <exception cref="ArgumentNullException">
+    /// The <paramref name="builder"/> is null.
+    /// </exception>
+    public static IRequestExecutorBuilder EnableMutationConvention(
+        this IRequestExecutorBuilder builder)
+    {
+        if (builder is null)
+        {
+            throw new ArgumentNullException(nameof(builder));
+        }
+
+        builder
+            .TryAddTypeInterceptor<ErrorTypeInterceptor>()
+            .TryAddTypeInterceptor<InputArgumentTypeInterceptor>()
+            .TryAddTypeInterceptor<PayloadTypeInterceptor>()
+            .Services
+            .AddSingleton<IParameterExpressionBuilder, InputParameterExpressionBuilder>();
+
+        return builder;
+    }
+
+    /// <summary>
+    /// Defines the common interface that all errors implement.
+    /// To specify the interface you can either provide a interface runtime type or a HotChocolate
+    /// interface schema type.
+    ///
+    /// This has to be used together with <see cref="ErrorAttribute"/>  or
+    /// <see cref="ErrorObjectFieldDescriptorExtensions.Error"/>
+    /// </summary>
+    /// <param name="builder">
+    /// The request executor builder
+    /// </param>
+    /// <typeparam name="T">
+    /// The type that is used as the common interface
+    /// </typeparam>
+    /// <returns>
+    /// The schema builder
+    /// </returns>
+    public static IRequestExecutorBuilder AddErrorInterfaceType<T>(
+        this IRequestExecutorBuilder builder) =>
+        builder.ConfigureSchema(x => x.AddErrorInterfaceType<T>());
+
+    /// <summary>
+    /// Defines the common interface that all errors implement.
+    /// To specify the interface you can either provide a interface runtime type or a HotChocolate
+    /// interface schema type.
+    ///
+    /// This has to be used together with <see cref="ErrorAttribute"/>  or
+    /// <see cref="ErrorObjectFieldDescriptorExtensions.Error"/>
+    /// </summary>
+    /// <param name="builder">
+    /// The request executor builder
+    /// </param>
+    /// <param name="type">
+    /// The type that is used as the common interface
+    /// </param>
+    /// <returns>
+    /// The request executor builder
+    /// </returns>
+    public static IRequestExecutorBuilder AddErrorInterfaceType(
+        this IRequestExecutorBuilder builder,
+        Type type) =>
+        builder.ConfigureSchema(x => x.AddErrorInterfaceType(type));
+}

src/HotChocolate/Core/src/Types.Mutations/Errors/CreateError.cs

@@ -0,0 +1,3 @@
+namespace HotChocolate.Types;
+
+internal delegate object? CreateError(Exception exception);

src/HotChocolate/Core/src/Types.Mutations/Errors/ErrorAttribute.cs

@@ -0,0 +1,187 @@
+namespace HotChocolate.Types;
+
+/// <summary>
+/// The <see cref="ErrorAttribute"/> registers a middleware that will catch all exceptions of
+/// type <see cref="ErrorAttribute.ErrorType"/>. By annotating the attribute the response type
+/// of the annotated resolver, will be automatically extended by a field of type
+/// <c>errors:[Error!]</c>. This field will return errors that are caught by the middleware.
+/// All the other fields on this type will be rewritten to nullable types. In case of a error
+/// these fields will be set to null.
+/// <para>
+/// There are three different ways to map exceptions to GraphQL errors.
+/// </para>
+/// </summary>
+/// <remarks>
+/// The idea of the error middleware is to keep the resolver clean of any error handling code
+/// and use exceptions to signal a error state. The HotChocolate schema is automatically
+/// rewritten into a common error handling pattern.
+/// <a href="https://xuorig.medium.com/a-guide-to-graphql-errors-bb9ba9f15f85">Learn More</a>
+/// </remarks>
+/// <example>
+/// <para>
+/// There are three different ways to map exceptions to GraphQL errors.
+/// </para>
+/// <list type="number">
+/// <item>
+/// <para>
+/// <b>Catching exceptions directly</b>
+/// </para>
+/// If <see cref="ErrorAttribute.ErrorType"/> is a exception, the exception is automatically
+/// mapped into a GraphQL error and the middleware will catch this exception
+/// <code>
+/// public class Mutation
+/// {
+///     [Error(typeof(SomeSpecificDomainError))]
+///     [Error(typeof(SomeOtherError))]
+///     public CreateUserPayload CreateUser(CreateUserInput input)
+///     {
+///        // ...
+///     }
+/// }
+///
+/// public record CreateUserInput(string UserName);
+///
+/// public record CreateUserPayload(User User);
+/// </code>
+/// This will generate the following schema
+/// <code>
+/// type Mutation {
+///   createUser(input: CreateUserInput!): CreateUserPayload!
+/// }
+///
+/// input CreateUserInput {
+///   userName: String!
+/// }
+///
+/// type CreateUserPayload {
+///   user: User
+///   errors: [CreateUserError!]
+/// }
+///
+/// type User {
+///   username: String
+/// }
+///
+/// interface Error {
+///   message: String!
+/// }
+///
+/// type SomeSpecificDomainError implements Error {
+///   message: String!
+/// }
+///
+/// type SomeOtherDomainError implements Error {
+///   message: String!
+/// }
+///
+/// union CreateUserError = SomeSpecificDomainError | SomeOtherDomainError
+/// </code>
+///    </item>
+/// <item>
+/// <para>
+/// <b>Map Exceptions with a factory method</b>
+/// </para>
+/// <para>
+/// If there should be any translation between exception and error, you can defined a class
+/// with factory methods. These factory methods receive a <see cref="Exception"/> and return
+/// a object which will be used as the representation of the error
+/// </para>
+/// <para>
+/// A factory method has to be `public static` and the name of the method has to be
+/// `CreateErrorFrom`. There should only be one parameter of type <see cref="Exception"/> and
+/// it can return a arbitrary class/struct/record that will be used as the representation
+/// of the error.
+/// </para>
+/// <code>
+/// public class MyCustomError
+/// {
+///     public static MyCustomError CreateErrorFrom(DomainExceptionA ex)
+///     {
+///         return new MyCustomError();
+///     }
+///
+///     public static MyCustomError CreateErrorFrom(DomainExceptionB ex)
+///     {
+///         return new MyCustomError();
+///     }
+///
+///     public string Message => "My custom error Message";
+/// }
+///
+/// public class Mutation
+/// {
+///     [Error(typeof(MyCustomError))]
+///     public CreateUserPayload CreateUser(CreateUserInput input)
+///     {
+///        // ...
+///     }
+/// }
+///
+/// public record CreateUserInput(string UserName);
+///
+/// public record CreateUserPayload(User User);
+/// </code>
+/// </item>
+/// <item>
+/// <para>
+/// <b>Map exceptions with a constructors</b>
+/// </para>
+/// <para>
+/// As a alternative to mapping exceptions with factory methods, you can also map the exception
+/// in the constructor of the object that should be used to represent the error in the schema.
+/// </para>
+/// <code>
+/// public class MyCustomError
+/// {
+///     public MyCustomError(MyCustomDomainException exception)
+///     {
+///         Message = exception.Message;
+///     }
+///
+///     public MyCustomError(MyCustomDomainException2 exception)
+///     {
+///         Message = exception.Message;
+///     }
+///
+///     public string Message { get; }
+/// }
+///
+/// public class Mutation
+/// {
+///     [Error(typeof(MyCustomError))]
+///     public CreateUserPayload CreateUser(CreateUserInput input)
+///     {
+///        // ...
+///     }
+/// }
+/// </code>
+/// </item>
+/// </list>
+/// </example>
+public class ErrorAttribute : ObjectFieldDescriptorAttribute
+{
+    /// <inheritdoc cref="ErrorAttribute"/>
+    /// <param name="errorType">
+    /// The type of the exception, the class with factory methods or the error with an exception
+    /// as the argument. See the examples in <see cref="ErrorAttribute"/>.
+    /// </param>
+    public ErrorAttribute(Type errorType)
+    {
+        ErrorType = errorType;
+    }
+
+    /// <summary>
+    /// The type of the exception, the class with factory methods or the error with an exception
+    /// as the argument. See the examples in <see cref="ErrorAttribute"/>.
+    /// </summary>
+    public Type ErrorType { get; }
+
+    /// <inheritdoc />
+    public override void OnConfigure(
+        IDescriptorContext context,
+        IObjectFieldDescriptor descriptor,
+        MemberInfo member)
+    {
+        descriptor.Error(ErrorType);
+    }
+}