Docker for Rails Developers/

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Debugging

Debugging

Learn how to debug your app using byebug.

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Byebug debugger

No chapter on testing would be complete without some mention of how to debug our application when it is not behaving as we would expect. Imagine there is a problem with our welcome_controller.rb.

Let’s use the byebug debugger that is included as standard with a Rails app. Let’s add a byebug breakpoint to our welcome_controller.rb:

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class WelcomeController < ApplicationController
	def index
		redis = Redis.new(host: "redis", port: 6379)
		redis.incr "page hits"
		
		@page_hits = redis.get "page hits"
 		byebug
	end
end

In case your Rails server is up, you need to stop it:

$ docker-compose stop web

When we want an interactive ...