This is little demo app of Clean Architecture with CQRS pattern including JWT authorization. Task was to create JSON REST web service for hotel search. The service must have two API interfaces:
- CRUD interface for hotel data management (authorized)
- Standard CRUD operations with standard validation
- Search interface that returns the list of all hotels to the user (public)
- For each hotel, return the name, the price, and the distance from my current geo location
- The list should be ordered. Hotels that are cheaper and closer to my current location should be positioned closer to the top of the list. Hotels that are more expensive and further away should be positioned closer to the bottom of the list.
- Independence of Frameworks
- Separation of Concerns (structured in layers):
- Innermost Layer (Entities/Domain Models)
- Use Cases or Application Layer
- Interface Adapters or Presenters
- Frameworks and Drivers
- Testability
- Dependency Rule
- Simplicity and Maintainability
Overall, Clean Architecture emphasizes the separation of concerns, maintainability, and testability by structuring the codebase in a way that promotes flexibility and adaptability to changes in requirements or technologies. It aims to create systems that are resilient to changes in external factors, ensuring the longevity and sustainability of software projects.
So, project structure looks like:
LeHotelMax Soultion
LeHotelMax.Application (Class library project)
└── Common (Supporting stuff)
└── Hotels (Use cases)
└── CQRS (Command Query Responsibility Segregation)
└── Users (Use cases)
└── CQRS (Command Query Responsibility Segregation)
└── ServiceConfiguration.cs (Dependency injection)
...
LeHotelMax.Domain (Class library project)
└── Common (Supporting stuff)
└── Aggregates (Domain objects)
...
LeHotelMax.Infrastructure (Class library project)
└── Data
└── Identity (IdentityUser related)
└── Repository (Persistance related)
└── ApplicationDbContext.cs
└── ServiceConfiguration.cs (Dependency injection)
...
LeHotelMax.WebApi (ASP .NET(8) Core Web API) - startup project
└── Controllers (user interactions with service)
└── Dtos (Data transfer objects)
└── Logs (Logs are here)
└── ServiceConfiguration.cs (Dependency injection)
└── Program.cs (App entry point)
...
CQRS is a design pattern that separates the responsibility of handling read (queries) and write (commands) operations in an application by using separate models, thereby optimizing the read and write concerns independently.
Application use In Memory Database provider but that can be easily changed to maintain persistence such as MS SQL
HOTEL API (Hotel CRUD) require User to be authorized (using JWT token)
One admin user is included:
admin@localhost
Admin123!
Response body
{
"id": "de65431b-9b6d-4c37-95dd-9c12a3a2f6d6",
"userName": "admin@localhost",
"accessToken": "eyJhbGciOiJIUzI1NiIsInR5cCI6Ik..."
}
Use accessToken to be authorized on protected endpoints
There are preloaded Hotels in the system. We can use pagination to fetch data
curl -X 'GET' \
'https://YOUR-DOMAIN/api/v1/Hotel?PageNumber=2&PageSize=2' \
-H 'accept: */*' \
-H 'Authorization: Bearer eyJhbGciOiJIUzI1NiIs....'
Response body
{
"items": [
{
"id": 3,
"name": "Sheraton Zagreb Hotel",
"price": 163.25,
"geoLocation": {
"latitude": 45.8088,
"longitude": 15.9782
}
},
{
"id": 4,
"name": "Falkensteiner Hotel & Spa Zadar",
"price": 200,
"geoLocation": {
"latitude": 44.1992,
"longitude": 15.2103
}
}
],
"pageNumber": 2,
"totalPages": 4,
"totalCount": 7,
"hasPreviousPage": true,
"hasNextPage": true
}
The rest of hotel CRUD can be tested in the same way.
No authorization is required here. It calculates distance from a given location (your location) to find the best match hotel for you :)
For simplicity, we are using the Haversine formula. The Haversine formula is a very accurate way of computing distances between two points on the surface of a sphere using the latitude and longitude of the two points. More at: https://en.wikipedia.org/wiki/Haversine_formula
curl -X 'GET' \
'https://YOUR-DOMAIN/api/v1/HotelSearch?Latitude=45.8088&Longitude=15.9773&PageNumber=1&PageSize=2' \
-H 'accept: */*'
Response body
{
"items": [
{
"distance": 0.06975808013819948,
"id": 3,
"name": "Sheraton Zagreb Hotel",
"price": 163.25,
"geoLocation": {
"latitude": 45.8088,
"longitude": 15.9782
}
},
{
"distance": 0.20736895956904278,
"id": 1,
"name": "Esplanade Zagreb Hotel",
"price": 150,
"geoLocation": {
"latitude": 45.8105,
"longitude": 15.9762
}
}
],
"pageNumber": 1,
"totalPages": 4,
"totalCount": 7,
"hasPreviousPage": false,
"hasNextPage": true
}
"distance": 0.06975808013819948 is expressed in km from the given location
| Name | Description |
|---|---|
| AutoMapper | library that automates the mapping of properties between object |
| MediatR | implementation of the Mediator design pattern |
| FluentValidation | interface for defining and applying validation rules to objects |
| Microsoft Entity Framework Core | cross-platform Object-Relational Mapping (ORM) framework |
| Serilog with Sensitive Enrichers | library that provides a flexible and expressive logging API |
| Swashbuckle | generate interactive API documentation |
| xUnit | testing framework for the .NET ecosystemn |
- Download solution code (or git clone)
- Open it with VS2022
- Set WebApi as startup project
- Hit the run button and wait for the browser to pop up with swagger UI
TODO: Add more tests