Here's a review I wrote about the book 'Perl Testing: A Developer's Notebook' by Ian Langworth & chromatic.
"Excellent overview and introduction to the art of testing Perl programs. This modestly-sized book covers a wide range of types of testing from the very simple Perl script to the more advanced web application. It's not only about writing tests but managing them as well and then making sure that your code can be distributed in a useful manner. I especially found the chapter about testing untestable code very insightful, where the use of mocking modules and mocking objects is essential. Have you ever needed to override live code by hacking deeply into their packages? Well, this book will help you out with this delicate matter and make you more confident with testing, testing and testing. Most people have an aversion to testing, but here you can get quickly up to speed and even enjoy the fine are of testing. There are many references to other CPAN modules which is useful to know about. Of course, any book authored by chromatic has to be worth the read."
O'Reilly books
"Excellent overview and introduction to the art of testing Perl programs. This modestly-sized book covers a wide range of types of testing from the very simple Perl script to the more advanced web application. It's not only about writing tests but managing them as well and then making sure that your code can be distributed in a useful manner. I especially found the chapter about testing untestable code very insightful, where the use of mocking modules and mocking objects is essential. Have you ever needed to override live code by hacking deeply into their packages? Well, this book will help you out with this delicate matter and make you more confident with testing, testing and testing. Most people have an aversion to testing, but here you can get quickly up to speed and even enjoy the fine are of testing. There are many references to other CPAN modules which is useful to know about. Of course, any book authored by chromatic has to be worth the read."
O'Reilly books