Debugging

###In Ruby/Rails raise varname.to_yaml is the most straightforward way to inspect a variable/object. When rails comes across a raise line, it stops the application and raises an "error" whose text contains the text (yaml) representation of the variable/object.

After a page request (at the top of each controller action), a variable called "params" exists containing the data submitted by the form or implied by the URL. raise params.to_yaml is also super useful.

Pry is a much more powerful replacement for irb. It also allows you to enter breakpoints (binding.pry), where the code stops running and you are dumped into a pry environment, with full access to all of the live variables.

Jazz Hands is a set of Pry-related gems which enhance pry even further. In particular, Pry Debugger is a really useful one.

Better Errors gives you a lot of information up front, in the browser, when Rails encounters an error.