rspec on Andrés Álvarez

Testing JSON API Strong Parameters in Rails

Thu, 25 May 2017 00:00:00 +0000

Recently I was experiencing a problem with a Rails API where I would update a model with new attributes, and then proceeded to add the new attributes to the model's factory, and then add the corresponding model and request specs.

The problem was that I would forget to whitelist the new attributes in the controller. Then running the request specs would not detect the error since I only test against one updated attribute that was whitelisted long ago. This became really annoying since I had no way to know if the new attributes were being whitelisted or not, and my tests weren't saying anything about it. This problem becomes even more apparent when the list of whitelisted attributes starts becoming very long.

In an API following the JSON API specification, here is an example of how the strong parameters method would look like:

def thing_params
  params.require(:data).require(:attributes).permit(:color, :size, :age, :name,
      :owner, :origin, :location, :purpose, :price, :alive)
end

As you can see, the list of attributes is getting pretty long. And we do not want to explicitly keep adding more attributes to the test.

Testing Strong Parameters in Controller Specs

After the release of Rails 5 I started ditching controller specs in favor of request specs. I like this approach and I think it's great, but I think it would be too much unecessary work to test that all the necessary attributes are whitelisted, in the request spec. Therefore I proceeded to create very simple controller specs that would test that all attributes of importance are whitelisted in the controller.

Testing a Rails API With RSpec

Mon, 15 May 2017 00:00:00 +0000

As I continue to improve me API testing skills in Rails, I have come to point where I really feel comfortable with all the tools I need to correctly add useful tests to my API. This post explains how I usually test my Rails APIs using RSpec.

Setting Up the Necessary Tools

In addition to RSpec, there are a few tools that make my testing experience much easier. These are:

After Adding these gems to the Gemfile. I proceed to create a /support directory under the /spec directory. This directory will contain the additional configuration of the above tools, as well as some helper definitions that our specs will use.

/spec/support/shoulda.rb:

Shoulda::Matchers.configure do |config|
  config.integrate do |with|
    # Choose a test framework:
    with.test_framework :rspec

    # Or, choose the following (which implies all of the above):
    with.library :rails
  end
end

Integrating TravisCI With Rails and Heroku

Tue, 07 Mar 2017 00:00:00 +0000

Adding TravisCI to your application's deployment flow will enable you to spot any build fails or test fails during deployment without affecting your production environment.

In this post I go over on how to integrate TravisCI with a Rails 4 application that uses Postgresql, Rspec, and is later deployed to Heroku if the Travis build is successful.

Setting up TravisCI

Assuming you already have an account in TravisCI, look for the Github repository of the Rails application and enable it. Then we will want to add a .travis.yml file to the application's root directory with the following contents:

language: Ruby
rvm:
  - 2.3.0

The configuration above tells TravisCI that our application will use Ruby 2.3.0. Once you commit and push the change above to the master branch, Travis will begin creating the build, which might take a few minutes.

Configure Postgresql

Seems our Rails application uses Postgresql, we need to configure TravisCI to run our build with a Postgresql database. To do this we will add the following configuration to .travis.yml:

services:
  - postgresql

Then we will add another configuration that will make Travis create a Postgresql database with username postgres and blank password for the build:

before_script:
  - psql -c 'create database travis_ci_test;' -U postgres