MoqExtensions.cs

using System.Reflection;
using Moq.Language;
using Moq.Language.Flow;

namespace Parse.Tests;

// MIT licensed, w/ attribution:
// http://stackoverflow.com/a/19598345/427309
public static class MoqExtensions
{
    public delegate void OutAction<TOut>(out TOut outVal);
    public delegate void OutAction<in T1, TOut>(T1 arg1, out TOut outVal);

    public static IReturnsThrows<TMock, TReturn> OutCallback<TMock, TReturn, TOut>(this ICallback<TMock, TReturn> mock, OutAction<TOut> action) where TMock : class => OutCallbackInternal(mock, action);

    public static IReturnsThrows<TMock, TReturn> OutCallback<TMock, TReturn, T1, TOut>(this ICallback<TMock, TReturn> mock, OutAction<T1, TOut> action) where TMock : class => OutCallbackInternal(mock, action);

    private static IReturnsThrows<TMock, TReturn> OutCallbackInternal<TMock, TReturn>(ICallback<TMock, TReturn> mock, object action) where TMock : class
    {
        mock.GetType().Assembly.GetType("Moq.MethodCall").InvokeMember("SetCallbackWithArguments", BindingFlags.InvokeMethod | BindingFlags.NonPublic | BindingFlags.Instance, null, mock, new[] { action });
        return mock as IReturnsThrows<TMock, TReturn>;
    }
}