Fluent Validator Engine - Helper class to find all validators and provide a common way of validating objects.

Fluent Validator Engine.cs

/// <summary>
/// Helper class to find all validators and provide a common way of validating objects. 
/// </summary>
public class ValidationEngine
{
	private static readonly Dictionary<Type, IValidator> AllValidatorsInAssembly;
	
	static ValidationEngine()
	{
		AllValidatorsInAssembly = new Dictionary<Type, IValidator>();
		FindAndInstantiateAllAbstractValidators();
	}
	
	private static void FindAndInstantiateAllAbstractValidators()
	{
		// https://stackoverflow.com/questions/8645430/get-all-types-implementing-specific-open-generic-type
		foreach (var abstractValidator in from x in Assembly.GetAssembly(typeof(ValidationEngine)).GetTypes()
										  let y = x.BaseType
										  where !x.IsAbstract && !x.IsInterface &&
												y != null && y.IsGenericType &&
												y.GetGenericTypeDefinition() == typeof(AbstractValidator<>)
										  select x)
		{
			// No need to safeguard this - if we get null's fail hard 
			var typeOfValidator = abstractValidator.BaseType.GenericTypeArguments.First().UnderlyingSystemType;
	
			// https://stackoverflow.com/questions/731452/create-instance-of-generic-type
			var validator = (IValidator)Activator.CreateInstance(abstractValidator);
	
			AllValidatorsInAssembly.Add(typeOfValidator, validator);
		}
	}
	
	/// <summary>
	/// Will look at all registered abstract validators
	/// Find the validator matching the given type of item
	/// Run validate method to determine if item is valid
	/// </summary>
	/// <typeparam name="T">Not Needed - Type will be inferred</typeparam>
	/// <param name="item">Item for validation</param>
	/// <returns>ValidationResult</returns>
	public static ValidationResult Validate<T>(T item)
	{
		var classRequiringValidation = typeof(T);
	
		if (AllValidatorsInAssembly.ContainsKey(classRequiringValidation) == false)
			throw new Exception($"Unable to locate validator {classRequiringValidation.FullName} - " +
								$"Please create a new AbstractValidator<{classRequiringValidation.FullName}>");
	
		return AllValidatorsInAssembly[classRequiringValidation].Validate(item);
	}
}