add more tests

[leonorader]

Right now, the lib has only a few tests, I tested only manually.

[miguelhrocha]

Do you want help with this @leonorader ?

[leonorader]

@aComanche it would be great if you would help with this! :)

[miguelhrocha]

Do you have some any priority list to see what can I test first?

[leonorader]

Not really, I was about to start with unit tests, but it is really up to you :) @aComanche