Software tests are crucial to guarantee the delivery of a good quality product, indentify bugs, additionally offer comfort in the maintenance phase, code refactoring or even when changing team members, in addition to other benefits listed in part 1. As mentioned in the part 1, we will create a project with its corresponding test project using xUnit and Coverlet. To bring the example to life, we will create a folder for the projects. Within the folder, we will have a class library and the test project. Code to be tested In the class library below, we will have a class that contains a method that takes a string as input and validates whether it is a number and if it has no more than 10 characters. Commands to create the class library project. Test with xUnit Next, we have the test project that uses xUnit, and upon creation, it already includes the Coverlet library. To confirm this, after creating the test project, if we open the file xUnitCoverletTest.csproj, we will find one of the PackageReference entries as coverlet.collector. The test class validates the result of the method execution. In our example, if the method receives a string with only numbers and no more than 10 characters, it should return true, otherwise, the result is false. Two approaches were used for testing, one that allows passing multiple inputs as parameters to test ([Theory]) and another without parameters ([Fact]). The test project must reference our class library to be able to test the methods available in the class library. The following command allows referencing the class library. To confirm if it’s correct, you can open the file xUnitCoverletTest.csproj and check if there is a ProjectReference tag.

Microsoft has been making efforts to position ASP.NET Core as an excellent choice for software development. Several indicators demonstrate notable progress, including benchmarks available on their website. According to these benchmarks, ASP.NET Core exhibits superior performance compared to NodeJS and Java. It is capable of processing a higher number of requests per second than NodeJS and Java. Entity Framework Core is an open-source Object-Relational Mapper (O/RM) that receives contributions from both Microsoft and the community. It is a cross-platform version of the well-known Entity Framework. Entity Framework Core has evolved at a faster pace compared to its predecessor, Entity Framework. It introduces several new features that are not available in the previous version. This rapid evolution has allowed Entity Framework Core to provide enhanced functionality and improved performance. Entity Framework Core Entity Framework Core (EF Core) is a library developed and maintained by Microsoft. Unlike Entity Framework, EF Core is open source, and this approach enables other people and organizations to contribute to the project. This impacts a faster evolution of EF Core compared to its predecessor. The involvement of the community has played a crucial role in introducing new features, improvements, and bug fixes to EF Core. EF Core provides a straightforward and clean approach for ASP.NET Core applications to access and store data in databases. Entity Framework Core (EF Core) is a Object-Relational Mapper (O/RM) designed as a lightweight, open-source, cross-platform, and extensible version of Entity Framework. A object-relational mapping (ORM) reduce the need for manual SQL queries and database management tasks, making the data access layer more streamlined and developer-friend. EF Core includes several additional features, such as: DbContext pooling — allows for the reuse of context instances. Each context instance is configured with several internal services and objects required to perform its tasks, and reusing them can result in performance gains in high-performance scenarios. Alternate keys — allow the definition of columns with unique values, in addition to primary keys. Global query filters — are filters applied globally, which restrict the data returned by a query based on a condition. This feature simplifies the application code, reduces the risk of incorrect data access. Entity Framework Core and database management systems EF Core supports various database management systems such as Oracle, SQL Server/Azure SQL Database, SQLite, MySQL, PostgreSQL, Azure Cosmos DB and In-memory (for testing). Important concepts in applications with EF Core Applications that use EF Core employ certain concepts, such as: Database Context — It is a class that maps database objects and application objects, configurations, and data initialization. The Database Context acts as a bridge between the application and the database to retrieve and persist data. Model — It is the class that is mapped to a table for retrieving or persisting data. The model is a C# class with additional configurations. There are two approaches to configure the models: 1. Data Annotations — This approach involves using attributes directly in the model class to define mappings, relationships, and constraints. 2. Fluent API configurations — This approach involves using the fluent API methods to configure mappings, relationships, and constraints in a separate configuration class.

This article is an extension of the theoretical article Components of Enterprise Software, which discusses the combination of software design concepts, specifically Hexagonal Architecture and Clean Architecture. It is necessary to read the previous article to understand the concepts applied here and the intended goals. This time, we will focus primarily on practical issues, namely the implementation of the design presented earlier. Design Proposal The following diagram is a result of combining the teachings of Hexagonal and Clean architectures, and it provides a detailed representation of the intended design for our software. This diagram provides a general, simple, and direct identification of all the layers in the design and their responsibilities: Entities (or domain) — Contains the core business rules. Use cases (or application) — Contains orchestration rules or the main operations of the application. Interface adapters — Mediate the application’s interaction with the external world (the infrastructure). Infrastructure (Frameworks, drivers) — The external world, which can include applications, services, libraries, APIs, etc. Entities and use cases constitute the core of the application, the central component of the architecture (the hexagon), and are responsible for encapsulating all the business logic. The Hexagonal Perspective From the perspective of Hexagonal Architecture, the application should be able to: Support multiple technologies (databases, message brokers, email services, etc.). Be testable without having all the technologies defined. Be developed without having all the technologies defined.