Dialyzer

Dialyzer (http://erlang.org/doc/man/dialyzer.html) is a tool that ships with Erlang and performs static analysis of code. It analyses compiled .beam files, making it available for all programming languages that run on the Erlang VM (such as Elixir!). While Dialyzer can be helpful on projects that don't have typespecs (as it can, for instance, find redundant code), its power is maximized on projects that have their functions annotated with typespecs. This way, Dialyzer is able to report on typing errors, which brings you closer to the security you can get on a statically-typed language.

Although we won't be exploring Dialyzer in this book, we highly recommend its usage, as it can be very helpful. Particularly, we feel that the Dialyxir library (https://github.com/jeremyjh/dialyxir), is a great way to integrate Dialyzer into Elixir projects, as it abstracts away part of the complexity of dealing with Dialyzer directly.