ByteDev.Exceptions 2.0.0

ByteDev.Exceptions

Small collection of exceptions in a .NET Standard library.

Installation

ByteDev.Exceptions has been written as a .NET Standard 2.0 library, so you can consume it from a .NET Core or .NET Framework 4.6.1 (or greater) application.

ByteDev.Exceptions is hosted as a package on nuget.org. To install from the Package Manager Console in Visual Studio run:

Install-Package ByteDev.Exceptions

Further details can be found on the nuget page.

Release Notes

Releases follow semantic versioning.

Full details of the release notes can be viewed on GitHub.

Usage

The library consists of a small set of custom exceptions:

• ArgumentDefaultException
• ArgumentEmptyException
• ArgumentNullOrEmptyException
• DependencyNullException
• EntityNotFoundException
• UnexpectedEnumValueException

ArgumentDefaultException

Use when an argument value cannot be it's default value.

if (myArg == default)
{
    throw new ArgumentDefaultException(nameof(myArg));
}

ArgumentEmptyException

Use when an argument value cannot be empty.

For example an empty string or empty collection.

if (name == string.Empty)
{
    throw new ArgumentEmptyException(nameof(name));
}

ArgumentNullOrEmptyException

Use when an argument value cannot be null or empty.

Often in such situations the programmer will decide to throw a ArgumentException.

Using a ArgumentNullOrEmptyException instead can give greater precision of the problem.

if (string.IsNullOrEmpty(name))
{
    throw new ArgumentNullOrEmptyException(nameof(name));
}

DependencyNullException

Use when an injected dependency is null.

Classes often have dependencies that are injected at runtime through constructor, method or property injection.

A developer will often check the passed in dependency and if null throw a ArgumentNullException.

Using a DependencyNullException instead can give greater precision of the problem.

public MyService(IRepository repository)
{
    _repository = repository ?? throw new DependencyNullException(typeof(IRepository));
}

EntityNotFoundException

Use when an entity is expected to exist and does not.

For example an entity retrieved from storage or a database.

Sometimes instead of returning null from the method throwing an exception may seem more appropriate.

var customer = customerRepository.GetCustomer(id);

if (customer == null)
{
    throw new EntityNotFoundException(typeof(Customer), id);
}

UnexpectedEnumValueException

Use when an unexpected enum value is encountered.

enum LightStatus
{
    Off,
    Dimmed,
    On
}

// ...

switch (lightStatus)
{
    case LightStatus.Off:
        // do something...
        break;

    case LightStatus.Dimmed:
        // do something...
        break;

    case LightStatus.On:
        // do something...
        break;

    default:
        throw new UnexpectedEnumValueException<LightStatus>(lightStatus);
}