Yan Cui
I help clients go faster for less using serverless technologies.
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Another good question on StackOverflow, and even better answer from Steven (miles better than what I managed!), the question was around how to implement an extension method to check whether a certain method has a particular attribute applied to it, mainly for the purpose of unit testing.
In his answer, Steven provided a couple of useful extension methods to get the metadata of a method using lambda expression and then check whether an attribute with the specified type has been applied to it:
public static MethodInfo GetMethod<T>(this T instance, Expression<Func<T, object>> methodSelector)
{
// Note: this is a bit simplistic implementation. It will
// not work for all expressions.
return ((MethodCallExpression)methodSelector.Body).Method;
}
public static MethodInfo GetMethod<T>(this T instance, Expression<Action<T>> methodSelector)
{
return ((MethodCallExpression)methodSelector.Body).Method;
}
public static bool HasAttribute<TAttribute>(this MemberInfo member) where TAttribute : Attribute
{
var attributes = member.GetCustomAttributes(typeof(TAttribute), true);
return attributes.Length > 0;
}
Nice, eh? I thought so too! Don’t forget to give him some much deserved up vote!
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