fabbbiob / guardclauses

A simple package with guard clause extensions.

NuGet: Ardalis.GuardClauses

Guard Clauses

A simple package with guard clause extensions.

Usage

    public void ProcessOrder(Order order)
    {
    	Guard.Against.Null(order, nameof(order));

        // process order here
    }

Supported Guard Clauses

• Guard.Against.Null (throws if input is null)
• Guard.Against.NullOrEmpty (throws if string input is null or empty)
• Guard.Against.NullOrWhiteSpace (throws if string input is null or whitespace)
• Guard.Against.OutOfRange (throws if integer/DateTime input is outside a provided range)
• Guard.Against.OutOfSQLDateRange (throws if DateTime input is outside the valid range of SQL Server DateTime values)

Extending with your own Guard Clauses

To extend your own guards, you can do the following:

    // Using the same namespace will make sure your code picks up your 
    // extensions no matter where they are in your codebase.
    namespace Ardalis.GuardClauses
    {
        public static class FooGuard
        {
            public static void Foo(this IGuardClause guardClause, string input, string parameterName)
            {
                if (input?.ToLower() == "foo")
                    throw new ArgumentException("Should not have been foo!", parameterName);
            }
        }
    }

    // Usage
    public void SomeMethod(string something)
    {
        Guard.Against.Foo(something, nameof(something));
    }

References

• Guard Clauses (podcast: 7 minutes)
• Guard Clause