Add Mediatr functional extensions

src/Codehard.Core.sln

@@ -49,6 +49,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Codehard.Functional.Marten"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Codehard.Functional.Marten.Tests", "Codehard.Functional\Codehard.Functional.Marten.Tests\Codehard.Functional.Marten.Tests.csproj", "{BCB6D4C3-DD27-43AD-B0E9-6C8DE6821AD5}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Codehard.Functional.Mediatr", "Codehard.Functional\Codehard.Functional.Mediatr\Codehard.Functional.Mediatr.csproj", "{8952083F-5A2A-4A37-9039-8588B08CA6EE}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -143,6 +145,10 @@ Global
 		{BCB6D4C3-DD27-43AD-B0E9-6C8DE6821AD5}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{BCB6D4C3-DD27-43AD-B0E9-6C8DE6821AD5}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BCB6D4C3-DD27-43AD-B0E9-6C8DE6821AD5}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8952083F-5A2A-4A37-9039-8588B08CA6EE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8952083F-5A2A-4A37-9039-8588B08CA6EE}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8952083F-5A2A-4A37-9039-8588B08CA6EE}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8952083F-5A2A-4A37-9039-8588B08CA6EE}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -173,5 +179,6 @@ Global
 		{6277AC9F-217C-4F89-8589-51FCB4E9BADF} = {2F98EF48-527C-44C5-8FC3-65F25C808AC9}
 		{8D62918D-C27F-45AF-B26A-437B594C0D5C} = {0C257E94-AD98-4AFB-93B7-B6F64EB7D2BA}
 		{BCB6D4C3-DD27-43AD-B0E9-6C8DE6821AD5} = {0C257E94-AD98-4AFB-93B7-B6F64EB7D2BA}
+		{8952083F-5A2A-4A37-9039-8588B08CA6EE} = {0C257E94-AD98-4AFB-93B7-B6F64EB7D2BA}
 	EndGlobalSection
 EndGlobal

src/Codehard.Functional/Codehard.Functional.Mediatr/Codehard.Functional.Mediatr.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net6.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="LanguageExt.Core" Version="4.4.7" />
+      <PackageReference Include="MediatR" Version="12.1.1" />
+    </ItemGroup>
+
+</Project>

src/Codehard.Functional/Codehard.Functional.Mediatr/ExpectedResultError.cs

@@ -0,0 +1,32 @@
+using LanguageExt;
+using LanguageExt.Common;
+
+using static LanguageExt.Prelude;
+
+namespace Codehard.Functional.Mediatr;
+
+public record ExpectedResultError : Expected
+{
+    public ExpectedResultError(object errorObject, Error? inner)
+        : base(string.Empty, 0, Optional(inner))
+    {
+        this.ErrorObject = errorObject;
+    }
+
+    public ExpectedResultError(object errorObject, Exception? exception = null)
+        : base(string.Empty, 0, exception == null ? Option<Error>.None : Option<Error>.Some(ErrorException.New(exception)))
+    {
+        this.ErrorObject = errorObject;
+    }
+
+    public override ErrorException ToErrorException() => ErrorException.New(this.ErrorObject.ToString() ?? string.Empty);
+
+    public override string ToString() => this.ErrorObject.ToString() ?? string.Empty;
+
+    public object ErrorObject { get; init; }
+
+    public void Deconstruct(out object errorObject)
+    {
+        errorObject = this.ErrorObject;
+    }
+}

src/Codehard.Functional/Codehard.Functional.Mediatr/ICommand.cs

@@ -0,0 +1,8 @@
+using LanguageExt;
+using MediatR;
+
+namespace Codehard.Functional.Mediatr;
+
+public interface ICommand<TCommandResult> : IRequest<Fin<TCommandResult>>
+{
+}

src/Codehard.Functional/Codehard.Functional.Mediatr/ICommandHandler.cs

@@ -0,0 +1,9 @@
+using LanguageExt;
+using MediatR;
+
+namespace Codehard.Functional.Mediatr;
+
+public interface ICommandHandler<in TCommand, TCommandResult> : IRequestHandler<TCommand, Fin<TCommandResult>>
+    where TCommand : ICommand<TCommandResult>
+{
+}

src/Codehard.Functional/Codehard.Functional.Mediatr/IQuery.cs

@@ -0,0 +1,8 @@
+using LanguageExt;
+using MediatR;
+
+namespace Codehard.Functional.Mediatr;
+
+public interface IQuery<TQueryResult> : IRequest<Fin<TQueryResult>>
+{
+}

src/Codehard.Functional/Codehard.Functional.Mediatr/QueryHandler.cs

@@ -0,0 +1,9 @@
+using LanguageExt;
+using MediatR;
+
+namespace Codehard.Functional.Mediatr;
+
+public interface IQueryHandler<in TQuery, TQueryResult> : IRequestHandler<TQuery, Fin<TQueryResult>>
+    where TQuery : IQuery<TQueryResult>
+{
+}