public async Task RequestsCorrectUrl() { var connection = Substitute.For <IApiConnection>(); var client = new UsersClient(connection); await client.GetByEmail("email"); Received.InOrder(async() => { await connection.GetAll <User>(Arg.Is <Uri>(u => u.ToString() == "users/find"), Arg.Is <Dictionary <string, string> >(d => d.Count == 2 && d["term"] == "email" && d["search_by_email"] == "1")); }); }