You should know right away: this book is short, 41 pages, stem to stern.
The prose can get clunky. Not unclear or incoherent, just lacking in grace, and there is one serious code error, already noted in the errata page for the book at O’Reilly Media. Hahn makes no mention of the active community of developers using and extending Jasmine nor of Jasmine’s shortcomings (it’s not good at testing DOM manipulations without an additional plugin) – this is very much “How To Get Started With Jasmine”.
Minus “why you should test your software” arguments and some enthusiastic coverage of CoffeeScript and Ruby, you’re left with something roughly equivalent to a high-quality Web tutorial. That’s nothing to sneeze at, but it’s not “The Definitive Guide”, either.