I am glad that this approach works for you but I am not brave enough to use a new library without a single test.
I guess this project isn't for you then.
Well I would use it, but I wouldn't contribute, because I write all my code in a test driven programming way. AFAIK Chuck Norris writes the code first, never the test.
If nothing breaks why would you complain?
In that case, I wouldn't. But I believe that it will happen eventually, this is not a 10lines project, has many lines of code and since it's new, I expect a lot to be changed. Then those changes are going to break features.
If you are worried about them breaking it as they develop it, but like the current implementation then just use the current implementation.
It's not a question of wether something might break, it's a question of when will it break and how long a new introduced bug might be undetcted, that could have easily detected by some tests? Bugs always happen in projects, if someone says otherwise, he either proved his program to be correct (e.g. in COQ) or is wrong (and sometimes both :).