/// <summary>
/// A really weird way to instanciate what we need to test, 
/// working arround internal classes and missing constructors
/// </summary>
private static FirebaseToken AssambleAToken(string subject, string phoneNumber)
{
    // The thing we want to create
    var fireType = typeof(FirebaseToken);

    // Get Firebase Assambly
    var assembly = fireType.Assembly;

    // Find an internal type that handles the args
    var argType = assembly.GetTypes()
        .FirstOrDefault(a => a.Name == "FirebaseTokenArgs");

    // Create the instance without using any constructor
    var args = FormatterServices.GetUninitializedObject(argType);

    // Get all the properties
    var argProps = argType.GetProperties();

    // Set the subject
    argProps.First(a => a.Name == "Subject").SetValue(args, subject);

    // Set claims
    var claims = new Dictionary<string, object>
    {
        { "phone_number", phoneNumber }
    };
    argProps.First(a => a.Name == "Claims").SetValue(args, claims);

    // Get the appropiate internal ctor (im starting to hate my life)
    var ctors = fireType.GetConstructors(BindingFlags.NonPublic | BindingFlags.Instance);

    // Instanciate the final result with the weirdly formatted args, and return it
    return ctors[0].Invoke(new object[] { args }) as FirebaseToken;
}

public interface IFirebaseService
{
    Task<User> GetUserAsync(string uid);
    Task UpdateUserAsync(UpdateUserArgs args);
    Task SetRoleAsync(string uid, UserRole role);
    Task<string> GenerateEmailVerificationLinkAsync(string email);
}

/// <summary>
/// A really weird way to instanciate what we need to test, 
/// working arround internal classes and missing constructors
/// If you're brave enough try to understand it, i mean, it's not as bad
/// it's full of comments.
/// </summary>
private static FirebaseToken AssambleAToken(string subject, string phoneNumber)
{
    // The thing we want to create
    var fireType = typeof(FirebaseToken);

    // Get firebaseToken internal args
    var internalTypes = fireType.GetNestedTypes(BindingFlags.NonPublic);

    // Find an internal type that handles the args
    var argType = internalTypes
        .FirstOrDefault(a => a.Name == "Args");

    // Create the instance without using any constructor
    var args = FormatterServices.GetUninitializedObject(argType);

    // Get all the properties
    var argProps = argType.GetProperties(BindingFlags.NonPublic | BindingFlags.Instance);

    // Set the subject
    argProps.First(a => a.Name == "Subject").SetValue(args, subject);

    // Set claims
    var claims = new Dictionary<string, object>
    {
        { "phone_number", phoneNumber }
    };
    argProps.First(a => a.Name == "Claims").SetValue(args, claims);

    // Get the appropiate internal ctor (im starting to hate my life)
    var ctors = fireType.GetConstructors(BindingFlags.NonPublic | BindingFlags.Instance);

    // Instanciate the final result with the weirdly formatted args, and return it
    return ctors[0].Invoke(new object[] { args }) as FirebaseToken;
}