README.md

Primary Constructors

We use Primary Constructors to achieve a better representation of required dependencies and initialization parameters and get rid of constructors with only assignments and no logic to have a simpler code.

⚠️

.NET 8 and C# 12 are required. If you are using Visual Studio and you get unsupported warning, make sure you get update.

Usage in Records

Since records use given parameter name as the name of its corresponding property name, we use PascalCase in parameter names of record primary constructors.

public record EmployeeRequest(string Name, string Surname);

Usage in Classes

For classes there are two types of usages for a parameter of the primary constructor, field and parameter.

As Fields

If the parameter is directly used as a field, place an underscore (_) as a prefix, just like a field name.

💡 This is mostly the case for dependency injection.

public class SalaryBase(SalaryCalculator _calculator)
{
    ...
}

As Parameters

If a parameter is assigned to a property, use camelCase.

public class Employee(string name, DateTime dateOfHire)
{
    public string Name { get; } = name;
    public DateTime DateOfHire { get; } = dateOfHire;
}

Initializing Base Class

Derived classes must follow parameter names in base constructors.

public class OutOfWorkingYearRangeException(string message)
    : Exception(message) { }

public class YearlySalary(SalaryCalculator _calculator)
    : SalaryBase(_calculator)
{
    ...
}

Potential Conflicts

In practice, it should not be the case for a class to have parameters both as fields and parameters. If you encounter such a case please consider refactoring your code.

When both field and parameter usage is possible for a class, prefer the parameter usage over field usage. Please see below demonstration;

public class Employee(string name) // This is the preferred usage
    : IPerson
{
    string IPerson.Name { get; } = name;
}

public class Employee(string _name)
    : IPerson
{
    string IPerson.Name => _name;
}

Constructor Overloads

If you need to add secondary constructors, you must use the this constructor initializer as shown below.

public class OutOfWorkingYearRangeException(string message, Exception? innerException)
    : Exception(message, innerException)
{
    public OutOfWorkingYearRangeException(string message)
       : this(message, default) { }
}