Development tips - don't use request as a variable name

Many web development frameworks like Ruby on Rails or Padrino or Sinatra make use of some magic variables. It's always a good idea to become at least partially familiar with these in case you fall into the trap of over-writing one of these, sort of akin to the way you can, in Javascript, carelessly declare a variable called "console" and completely destroy your ability to debug your javascript in chrome.

This sort of problem can arise in Ruby on Rails when you are hacking away in a controller. Perhaps you've got a gem in your project that calls an api on the web - Let's call it the rubyflewtoo api that issues a random number when you call the "get" method. You might be tempted to write some code like this:

request = rubyflewtoo.new
@random_number = request.get bounds: {'lower':10, 'upper':20}

And the gem magically gives you back a random number between your lower and upper bounds. The code makes sense and the variables look reasonably named - you are, after all, issuing a request for a random number over http. The problem with this, is the subtle bug that you've introduced if later in your controller you want to grab something like the ip address of the user for some location awareness, you've over written the default Rails request object.

Comments

Getting started with Ruby on Rails 3.2 and MiniTest - a Tutorial

For fun, I thought I would start a new Ruby on Rails project and use MiniTest instead of Test::Unit. Why? Well MiniTest is Ruby 1.9s testing framework dejour, and I suspect we will see more and more new projects adopt it. It has a built in mocking framework and RSpec like contextual syntax. You can probably get away with fewer gems in your Gemfile because of that. Getting started is always the hardest part - let's jump in with a new rails project rails new tddforme --skip-test-unit Standard stuff. MiniTest sits nicely next to Test::Unit, so you can leave it in if you prefer. I've left it out just to keep things neat and tidy for now. Now we update the old Gemfile: group :development, :test do gem "minitest" end and of course, bundle it all up.....from the command line: $ bundle Note that if you start experiencing strange errors when we get in to the generators later on, make sure you read about rails not finding a JavaScript runtime . Fire up...

Rails 3.2, MiniTest Spec and Capybara

What do you do when you love your spec testing with Capybara but you want to veer off the beaten path of Rspec and forge ahead into MiniTest waters? Follow along, and you'll have not one, but two working solutions. The setup Quickly now, let's throw together an app to test this out. I'm on rails 3.2.9. $ rails new minicap Edit the Gemfile to include a test and development block group :development, :test do gem 'capybara' gem 'database_cleaner' end Note the inclusion of database_cleaner as per the capybara documentation And bundle: $ bundle We will, of course, need something to test against, so for the sake of it, lets throw together a scaffold, migrate our database and prepare our test database all in one big lump. If you are unclear on any of this, go read the guides . $ rails g scaffold Book name:string author:string $ rake db:migrate $ rake db:test:prepare Make it minitest To make rails use minitest , we simply add a require ...

Getting started with Docker

Docker, in the beginning, can be overwhelming. Tutorials often focus on creating a complex interaction between Dockerfiles, docker-compose, entrypoint scripts and networking. It can take hours to bring up a simple Rails application in Docker and I found that put me off the first few times I tried to play with it. I think a rapid feedback loop is essential for playing with a piece of technology. If you've never used Docker before, then this is the perfect post for you. I'll start you off on your docker journey and with a few simple commands, you'll be in a Docker container, running ruby interactively. You'll need to install Docker. On a Mac, I prefer to install Docker Desktop through homebrew: brew cask install docker If you're running Linux or Windows, read the official docs for install instructions. On your Mac, you should now have a Docker icon in your menu bar. Click on it and make sure it says "Docker desktop is running". Now open a terminal and ty...

Ruby flew too

Search This Blog