"there's no response to the last one" - the last one of what? of lines 47-49? i don't know what you mean by that, please use less implicit references. for instance, say you're talking about lines 47-49 here (although that's probably not the case), and your point is that 49 returns undefined instead of a value. then instead of saying "there's no response to the last one" you could say "there's no response to line 49", thereby removing one implicit reference. then to make your language even clearer, you could split it up into 'instructions to reproduce', 'expected', and 'actual'. So for instance:

    looking at the code on line 49, it does not return a value. i would expect it to 
    always return true in case of success, or false in case of failure

this is just an example, but hth. in any case, thanks again for all your effort to improve the code structure and the developer API of our library!