Add mediatr handlers with tests

Author: jicking

JixMinApi/Features/Todo/Commands/CreateTodoCommand.cs

@@ -0,0 +1,36 @@
+using JixMinApi.Shared;
+using MediatR;
+
+namespace JixMinApi.Features.Todo.Commands;
+
+public record CreateTodoCommand(TodoCreateDto input) : IRequest<Result<TodoDto>>;
+
+public class CreateTodoCommandHandler : IRequestHandler<CreateTodoCommand, Result<TodoDto>>
+{
+    private readonly TodoDb _db;
+    private readonly ILogger<CreateTodoCommandHandler> _logger;
+
+    public CreateTodoCommandHandler(TodoDb db, ILogger<CreateTodoCommandHandler> logger) => (_db, _logger) = (db, logger);
+
+    public async Task<Result<TodoDto>> Handle(CreateTodoCommand request, CancellationToken cancellationToken)
+    {
+        var todo = new Todo() { Name = request.input.Name, IsComplete = request.input.IsComplete };
+
+        try
+        {
+            await _db.Todos.AddAsync(todo);
+            await _db.SaveChangesAsync();
+
+            _logger.LogInformation("Todo {Id} is successfully created", todo.Id);
+            // await _emailService.SendEmail(email);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError("Todo {Id} failed due to an error: {ExMessage}",
+            todo.Id, ex.Message);
+            return new Result<TodoDto>(ex);
+        }
+
+        return new Result<TodoDto>(todo.ToDto());
+    }
+}

JixMinApi/Features/Todo/Extensions.cs

@@ -16,4 +16,25 @@ public static void MapTodoApi(this WebApplication app)
         group.MapGet("/", TodoApi.GetAllTodos);
         group.MapPost("/", TodoApi.CreateTodo);
     }
+
+    public static TodoDto ToDto(this Todo model)
+    {
+        return new TodoDto(model.Id, model.Name, model.IsComplete);
+    }
+
+    public static List<TodoDto> ToDto(this IList<Todo> model)
+    {
+        var result = new List<TodoDto>();
+        foreach (var item in model)
+            result.Add(item.ToDto());
+        return result;
+    }
+    public static void SeedTestData(this TodoDb db)
+    {
+        if (db.Todos.Any())
+            return;
+
+        db.Todos.AddRange(TodoDbDefaultValues.TestTodos);
+        db.SaveChanges();
+    }
 }

JixMinApi/Features/Todo/Queries/GetAllTodosQuery.cs

@@ -0,0 +1,24 @@
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+
+namespace JixMinApi.Features.Todo.Queries;
+
+public record GetAllTodosQuery : IRequest<List<TodoDto>>;
+
+public class GetAllTodosQueryHandler : IRequestHandler<GetAllTodosQuery, List<TodoDto>>
+{
+    private readonly TodoDb _db;
+    private readonly ILogger<GetAllTodosQueryHandler> _logger;
+
+    public GetAllTodosQueryHandler(TodoDb db, ILogger<GetAllTodosQueryHandler> logger) => (_db, _logger) = (db, logger);
+
+    public async Task<List<TodoDto>> Handle(GetAllTodosQuery request, CancellationToken cancellationToken)
+    {
+        _logger.LogDebug($"Start query");
+        var data = await _db.Todos
+            .AsNoTracking()
+            .ToListAsync();
+        _logger.LogDebug($"End query");
+        return data.ToDto();
+    }
+}

JixMinApi/Features/Todo/README.md

@@ -0,0 +1 @@
+Classes are  stored in single file for simplicity and will be extracted to individual file as needed.

JixMinApi/Features/Todo/TodoApi.cs

@@ -13,7 +13,7 @@ public static async Task<Ok<Todo[]>> GetAllTodos(TodoDb db)
 
     public static async Task<Created<Todo>> CreateTodo(TodoCreateDto input, TodoDb db)
     {
-        var todo = new Todo() { Name= input.Name, IsComplete= input.IsComplete };
+        var todo = new Todo() { Name = input.Name, IsComplete = input.IsComplete };
 
         db.Todos.Add(todo);
         await db.SaveChangesAsync();

JixMinApi/Features/Todo/TodoDbDefaultValues.cs

@@ -0,0 +1,18 @@
+namespace JixMinApi.Features.Todo;
+
+public static class TodoDbDefaultValues
+{
+    public static Guid TestTodoId = new Guid("684d921c-755a-450c-91d7-af495e116d9b");
+
+    public static List<Todo> TestTodos = new List<Todo> {
+        new Todo() {
+            Id = Guid.NewGuid(),
+            Name = "Completed Todo",
+            IsComplete = true,
+        },
+        new Todo() {
+            Id = TestTodoId,
+            Name = "Test Todo",
+        }
+    };
+}

JixMinApi/JixMinApi.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk.Web">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
@@ -9,6 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="MediatR" Version="12.2.0" />
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.3" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.3" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="8.0.3" />

JixMinApi/Program.cs

@@ -1,11 +1,11 @@
 using JixMinApi.Features.Todo;
-using Microsoft.EntityFrameworkCore;
 
 var builder = WebApplication.CreateBuilder(args);
 
 // Add services to the container.
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
+builder.Services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(typeof(Program).Assembly));
 
 // Api dependencies
 builder.Services.InjectTodoApiDependencies();

JixMinApi/Shared/Result.cs

@@ -0,0 +1,41 @@
+namespace JixMinApi.Shared;
+
+
+public class Result<T>
+{
+    public bool IsSuccess { get; set; }
+    public T? Value { get; set; }
+
+    public bool IsError { get; set; }
+    public Exception? Exception { get; set; }
+
+    public bool HasValidationError { get; set; }
+    public List<KeyValuePair<string, string>> ValidationErrors { get; set; } = new List<KeyValuePair<string, string>>();
+
+
+    public Result(T value)
+    {
+        Value = value;
+        IsSuccess = true;
+    }
+
+    public Result(Exception exception)
+    {
+        Exception = exception;
+        IsError = true;
+    }
+
+    public Result(List<KeyValuePair<string, string>> validationErrors)
+    {
+        ValidationErrors = validationErrors;
+        HasValidationError = true;
+    }
+
+    public Result(string field, string validationErrorMessage)
+    {
+        var validationErrors = new List<KeyValuePair<string, string>>();
+        validationErrors.Add(new KeyValuePair<string, string>(field, validationErrorMessage));
+        ValidationErrors = validationErrors;
+        HasValidationError = true;
+    }
+}

JixMinApiTests/Features/Todo/Commands/CreateTodoCommandHandlerTests.cs

@@ -0,0 +1,36 @@
+using JixMinApiTests.Features.Todo;
+using Xunit;
+using Assert = Microsoft.VisualStudio.TestTools.UnitTesting.Assert;
+
+namespace JixMinApi.Features.Todo.Commands.Tests;
+
+public class CreateTodoCommandHandlerTests
+{
+    private CreateTodoCommandHandler sut;
+
+    internal void Setup()
+    {
+        var (db, logger) = TestSetup.CreateTestMocks<CreateTodoCommandHandler>();
+        sut = new CreateTodoCommandHandler(db, logger);
+    }
+
+    [Fact()]
+    public void CreateTodoCommandHandlerTest()
+    {
+        Setup();
+        Assert.IsNotNull(sut);
+    }
+
+    [Fact()]
+    public async void HandleTest()
+    {
+        Setup();
+        var input = new TodoCreateDto("Test", true);
+        var result = await sut.Handle(new CreateTodoCommand(input), default);
+
+        Xunit.Assert.NotNull(result);
+        Assert.IsTrue(result.IsSuccess);
+        Assert.AreEqual(input.Name, result.Value.Name);
+        Assert.AreEqual(input.IsComplete, result.Value.IsComplete);
+    }
+}

JixMinApiTests/Features/Todo/Queries/GetAllTodosQueryHandlerTests.cs

@@ -0,0 +1,31 @@
+using JixMinApiTests.Features.Todo;
+using Xunit;
+using Assert = Microsoft.VisualStudio.TestTools.UnitTesting.Assert;
+
+namespace JixMinApi.Features.Todo.Queries.Tests;
+
+public class GetAllTodosQueryHandlerTests
+{
+    private GetAllTodosQueryHandler sut;
+
+    internal void Setup()
+    {
+        var (db, logger) = TestSetup.CreateTestMocks<GetAllTodosQueryHandler>();
+        sut = new GetAllTodosQueryHandler(db, logger);
+    }
+
+    [Fact()]
+    public void GetAllTodosQueryHandlerTest()
+    {
+        Setup();
+        Assert.IsNotNull(sut);
+    }
+
+    [Fact()]
+    public async void HandleTest()
+    {
+        Setup();
+        var result = await sut.Handle(new GetAllTodosQuery(), default);
+        Xunit.Assert.NotEmpty(result);
+    }
+}

JixMinApiTests/Features/Todo/TestSetup.cs

@@ -0,0 +1,23 @@
+using JixMinApi.Features.Todo;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace JixMinApiTests.Features.Todo;
+
+public static class TestSetup
+{
+    public static (TodoDb, ILogger<T>) CreateTestMocks<T>()
+    {
+        var logger = NullLogger<T>.Instance;
+
+        //	Set EF
+        var options = new DbContextOptionsBuilder<TodoDb>()
+            .UseInMemoryDatabase(Guid.NewGuid().ToString())
+            .Options;
+        var db = new TodoDb(options);
+        db.SeedTestData();
+
+        return (db, logger);
+    }
+}

JixMinApiTests/Features/Todo/TodoApiTests.cs

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
+    <Nullable>disable</Nullable>
 
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>

JixMinApiTests/JixMinApiTests.csproj

@@ -5,7 +5,7 @@ A simple minimal API Demo that uses vertical slice architecture.
 - [x] Setup base feature structure
 - [x] add github action for CI
 - [ ] pass unit tests
-- [ ] add mediatr
+- [x] add mediatr
 - [ ] add app insights/logging
 - [ ] set data migration process
 - [ ] set release process