AttributeConstraint
AttributeConstraint tests that a specified attribute is present
on a Type or other provider and that the value of the attribute
satisfies some other constraint.
using NUnit.Framework.Compatibility;
using System;
using System.Reflection;
namespace NUnit.Framework.Constraints
{
public class AttributeConstraint : PrefixConstraint
{
private readonly Type expectedType;
private Attribute attrFound;
public AttributeConstraint(Type type, IConstraint baseConstraint)
: base(baseConstraint)
{
expectedType = type;
descriptionPrefix = "attribute " + expectedType.FullName;
if (!IntrospectionExtensions.GetTypeInfo(typeof(Attribute)).IsAssignableFrom(expectedType.GetTypeInfo()))
throw new ArgumentException($"""{expectedType}""", "type");
}
public override ConstraintResult ApplyTo<TActual>(TActual actual)
{
Guard.ArgumentNotNull(actual, "actual");
Attribute[] customAttributes = AttributeHelper.GetCustomAttributes(actual, expectedType, true);
if (customAttributes.Length == 0)
throw new ArgumentException($"""{expectedType}""", "actual");
attrFound = customAttributes[0];
return baseConstraint.ApplyTo(attrFound);
}
protected override string GetStringRepresentation()
{
return $"""{expectedType}""{baseConstraint}""";
}
}
}