ModularMonolith

A playground for experimenting projects with a Modular Monolith Architecture - DDD, CQRS, MediatR, .NET 8, Entity Framework Core

Setup

• To get started, just create the databases ToDo and ToDo_Tests and update the connection string in appsettings (both in ToDoApp.Server.API and in ToDoApp.Tests.EndToEnd for integration tests) - the migration will be executed automatically on the first run.
• Set as startup the ToDoApp.Client.Blazor and ToDoApp.Server.API projects.

Tests

Unit tests

• Unit tests can be executed directly from Visual Studio, no additional setup. Every module has it's own set of unit tests that can be found under Modules[ModuleName]\Tests

Architecture tests

• The scope of architecture tests \tests\ToDoApp.Architecture.Tests is to enforce the dependency checks between modules and between layers in a specific module

End to end tests

• The scope of the end to end tests is to simulate an end to end flow by using WebApplicationFactory and an actual database

Performance tests

• There are two types of performance tests - by using k6 and nbomber
• To run stress tests with k6, you need first to install k6 by following these steps. After that, update the .\tests\ToDoApp.Performance.Tests\scripts.js file with the url, username and password that you want to use. Then run the application, open a cmd in the .\tests\ToDoApp.Performance.Tests folder and execute k6 run script.js
• To run the tests with nbomber, open the solution .\tests\ToDoApp.Performance.Tests\ToDoApp.Performance.Tests.sln, update the username and password of the user in appsettings.json. Run the application and after that run the performance tests as well. At the end, you'll get a report with all the results.

Health checks

Server has both endpoint and UI for checking the health of dependencies, in this case SQL Server and MassTransit:

• Endpoint - default address: https://localhost:5002/api/health
• UI - default address: https://localhost:5002/healthchecks-ui

Modules communications

There are two ways of communicating between modules:

1. Asynchronous - via MassTransit that runs locally
2. Synchronous - in two ways, you can check TasksModule for reference, CreateToDoCommandHandler command and implementations for IUsersApiClient:
   • via Contracts projects - direct dependency on Contracts project without direct dependency on any other module component
   • via SyncBus - dynamically by providing a route that runs dynamically the request, no direct dependency

Credits

• This implementation is based on the original ideas from devmentors and kgrzybek