How to call a generic extension method with reflection?

Question

I wrote the extension method GenericExtension. Now I want to call the extension method Extension. But the value of methodInfo is alway

Answer 1

In case you have an extension method like

public static class StringExtensions
{
    public static bool IsValidType(this string value);
}

you can invoke it (e. g. in tests) like so:

public class StringExtensionTests
{
    [Theory]
    [InlineData("Text", typeof(string), true)]
    [InlineData("", typeof(string), true)]
    [InlineData("Text", typeof(int), false)]
    [InlineData("128", typeof(int), true)]
    [InlineData("0", typeof(int), true)]
    public void ShouldCheckIsValidType(string value, Type type, bool expectedResult)
    {
        var methodInfo = 
            typeof(StringExtensions).GetMethod(nameof(StringExtensions.IsValidType),
            new[] { typeof(string) });
        var genericMethod = methodInfo.MakeGenericMethod(type);
        var result = genericMethod.Invoke(null, new[] { value });
        result.Should().Be(expectedResult);
    }
}