Mark Chavez

Sometimes I find myself wanting to test a ruby code outside the context of Rails. If what I want to test is trivial and so simple, then creating a single demo.rb looks sufficient. In most cases, I add unit tests so I can debug easily and effectively. Of course, that means we’re looking for something a little complex than our demo.rb.

In this article, I aim to share with you how I do this using my go-to testing framework, RSpec.

1. First, let’s setup the project and install RSpec.

Let’s create our project directory.

$ mkdir demo_project

Install rspec inside demo_project.

$ cd demo_project
$ touch Gemfile

Inside the Gemfile, add the ff. lines:

source 'https://rubygems.org'
gem 'rspec'

Then run bundle install.

2. Now that Rspec is installed, let’s set that up.

$ bundle exec rspec --init

Using bundle exec is important here to make sure we’re running the rspec version from our Gemfile. This command will generate a spec_helper.rb file inside the spec directory.

3. Let’s make a test file and make sure it works.

$ touch spec/demo_spec.rb

Write the spec you want to test.

require 'spec_helper'

RSpec.describe "Demo spec" do
  it "works" do
    expect(1 + 1).to eq 2
  end
end

Run bundle exec rspec spec and you should see the test pass.