CRUD-Sample

A production-shaped ASP.NET Core sample — clean architecture, EF Core, validation, ProblemDetails

Русская версия

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A compact ASP.NET Core Web API that demonstrates how a real CRUD service is shaped: layered architecture, EF Core on SQLite, FluentValidation, RFC 7807 ProblemDetails, pagination, OpenAPI, integration tests via WebApplicationFactory, and a Docker image. Everything fits in two production projects plus a test project — small enough to read top-to-bottom in one sitting.

What is showcased

• Layered architecture (Core/{Domain, Application, Infrastructure} + Api). The Api layer depends only on Application abstractions; Infrastructure is the only place that mentions EF Core.
• Domain primitives: Email value object enforces validity at construction.
• Sealed entity with private setters and a factory method — invalid Users can't exist.
• Use-case-style services (IUserService + UserResult discriminated union with records) instead of repository-leaking controllers.
• FluentValidation plugged into model binding for 400 + ValidationProblemDetails.
• RFC 7807 ProblemDetails for every error response (404, 409, 400).
• EF Core 10 + SQLite, with Email mapped via HasConversion.
• Compile-time logging ([LoggerMessage] source generator).
• Native OpenAPI (Microsoft.AspNetCore.OpenApi) served through Scalar UI.
• Health checks including DbContext liveness.
• WebApplicationFactory integration tests with EF in-memory database.
• Minimal API alongside the controller (/api/v1/users/count) for a side-by-side ergonomics comparison.
• Dockerfile (multistage, .NET 10 base) + docker-compose with a SQLite volume.

Project layout

CRUD-Sample/
├── src/
│   ├── CRUD-Sample.Api/                ASP.NET Core host
│   │   ├── Controllers/UsersController.cs
│   │   ├── ValidationExceptionHandler.cs
│   │   ├── Program.cs                  composition root
│   │   └── appsettings*.json
│   └── CRUD-Sample.Core/
│       ├── Domain/                     User, Email value object, IUserRepository, PageRequest
│       ├── Application/                DTOs, validators, IUserService, UserService
│       └── Infrastructure/             AppDbContext, EfUserRepository, DI extension
└── tests/
    └── CRUD-Sample.Tests/              WebApplicationFactory + xUnit + FluentAssertions

API

Method	Route	Description	Responses
GET	/api/v1/users	Paginated list (page, pageSize, sortBy, desc)	200
GET	/api/v1/users/{id}	Get a single user	200 / 404
POST	/api/v1/users	Create a user	201 / 400 / 409
PUT	/api/v1/users/{id}	Update a user	200 / 400 / 404 / 409
DELETE	/api/v1/users/{id}	Delete a user	204 / 404
GET	/api/v1/users/count	Minimal-API counterpart — just the count	200
GET	/health	Liveness + DbContext check	200 / 503
GET	/openapi/v1.json	OpenAPI document	200
GET	/scalar/v1	Interactive API explorer (dev only)	200

User schema

{
  "id":         12,
  "firstName":  "Ada",
  "lastName":   "Lovelace",
  "email":      "ada@example.com",
  "createdAt":  "2026-05-17T07:14:48Z"
}

email is required, must be a valid e-mail address, and is unique. firstName and lastName are required, max 100 characters each.

Quick start

dotnet restore
dotnet run --project src/CRUD-Sample.Api

Open http://localhost:5080/scalar/v1 to explore the API.

Docker

docker compose up --build
# API exposed on http://localhost:8080

Development

dotnet format --verify-no-changes        # check style
dotnet build --configuration Release     # build
dotnet test                              # 10 integration tests

Tech stack

Layer	Library
Framework	ASP.NET Core 10
Persistence	EF Core 10 + SQLite
Validation	FluentValidation + AspNetCore integration
OpenAPI	Microsoft.AspNetCore.OpenApi + Scalar
Health checks	Microsoft.Extensions.Diagnostics.HealthChecks.EntityFrameworkCore
Tests	xUnit + FluentAssertions + Microsoft.AspNetCore.Mvc.Testing (WebApplicationFactory)

License

MIT.