More than ever, we depend on software to get through our everyday lives. It's embedded in our smartphones, cars, children's toys, and household appliances (even our toasters), and it's transforming our world. This brave new world of technology offers exciting opportunities, but it has never been more important that we recognize and understand the risks to our security and safety. When software goes bad, the consequences can range from the farcical (such as the HealthCare.gov fiasco, in which a highly-touted government website crashed almost immediately upon being launched) to the tragic (as in the case of the Arizona woman who was killed by a self-driving car that didn't recognize her as a pedestrian).Testing is our line of defence against these software-related catastrophes. Yet, for years, it was seen as an afterthought-a chore that developers only carried out because they had to, and which they tried to complete as cheaply and quickly as possible.In The Book on Testing, Alex Rodov leads the reader on a personal and informal tour of the software-testing landscape, focusing on what happens when it isn't done properly. In easy-to-understand language, he offers real-life examples, as well as insights gained from decades of experience, to demonstrate why it doesn't have to be that way. Testing is difficult and can never be perfect. But if it's done well, we'll all be able to sleep better at night.