PSCmdletExtensions.cs

using System;
using System.Linq.Expressions;
using System.Management.Automation;

internal static class PSCmdletExtensions
{
    public static string GetMemberName<TType, TProperty>(
        this TType obj,
        Expression<Func<TType, TProperty>> expression)
    {
        return ((MemberExpression)expression.Body).Member.Name;
    }

    public static bool HasParameter<TType, TProperty>(
        this TType obj,
        Expression<Func<TType, TProperty>> expression)
        where TType : PSCmdlet
    {
        string parameterName = GetMemberName(obj, expression);
        return HasParameter(obj, parameterName);
    }

    public static bool HasParameter<TType>(
        this TType obj,
        string parameterName)
        where TType : PSCmdlet
    {
        return obj.MyInvocation.BoundParameters.ContainsKey(parameterName);
    }
}