Hi,

As my first post in this community, I decided to share my experience when I was testing Github's actions. I hope that you'll find it useful.

Objectif

My goal was to define a workflow composed of three steps for testing a rails application. These steps are:

1. Using Rubocup, the code will be statically analyzed against the Ruby style guide.
2. If the code passes the previous step, the RSpec tests are triggered to check if the new committed code didn't break anything somewhere else.
3. Finally, if all tests pass, you will get a report generated using SimpleCov to see how well the tests covered the application's code

The demo application

You can find the code that I used for the demo in this github repository. The application is a pretty simple, one "Post" model with two attributed "title" and "content". Postgres is the database to store the data.

if you check config/database.yml, you'll find that I have solely edited the section related to the testing database as I didn't need to run the application in the development environment.

#config/database.yml
test:
<<: *default
host: localhost
username: postgres
database: rails-github-action_test

Setting up the workflow

Create .github/workflows

The first step is to create a folder called .github/workflows in the root of your project folder.

Create the file that will describe the workflow

In this file, you write all the details need to run the workflow. The extension must .yml or .yaml.

Define the environment variables

This section is not required but it makes the reconfiguration of the workflow for other contexts easier. This section should start with the keyword env.

env:
  RUBY_VERSION: 2.4
  POSTGRES_USER: postgres
  POSTGRES_PASSWORD: ""
  POSTGRES_DB: postgres

• RUBY_VERSION will used to specify which version of ruby to use in the environment.
• POSTGRES_USER, POSTGRES_PASSWORD and POSTGRES_DB are the database related information.

Define the name of the workflow and when it should be triggered

name: Rails tests
on: [push,pull_request]
jobs:
  job1:
   ...
  job2:
   ...

• name is the name of the workflow that will appear in the Github Actions UI.
• on specify what are the events that will trigger the workflow. In this example, it'll be triggered on push and pull_request events.
• jobs will contain all the tasks to be defined in the workflow.

Describe jobs

Rubocop test

jobs:
  rubocop-test:
    name: Rubocop
    runs-on: ubuntu-18.04
    steps:
      - uses: actions/checkout@v1
      - uses: actions/setup-ruby@v1
        with:
          ruby-version: ${{ env.RUBY_VERSION }}
      - name: Install Rubocop
        run: gem install rubocop
      - name: Check code
        run: rubocop

• name is the name of the task.
• runs-on specifies which operating system will be used to run the task. In addition to ubuntu-18.04, you can use macOS and Windows Server 2019. For more details, you can check this link.
• In the section steps, we'll define the instructions that will run in the operating system in order to prepare it, and make it run the tests. In this example :
  • We call the action actions/checkout@v1 which necessary to check out the repository.
  • We call the action actions/setup-ruby@v1 to install ruby,
  • We use run to run the command to install rubocop gem install rubocop,
  • And finally, we run the test using rubocop. you can learn more about actions here.

If the code passes the test, you'll get something like this :

RSpec tests

For the RSpect test, We use a very similar code. The first difference is that we used needs to precise that the task should run only after the task rubocop-test is finished and passed successfully.

job:
 ...
   rspec-test:
    name: RSpec
    needs: rubocop-test
    runs-on: ubuntu-18.04
    steps:
      - uses: actions/checkout@v1
      - uses: actions/setup-ruby@v1
        with:
          ruby-version: ${{ env.RUBY_VERSION }}
      - name: Install postgres client
        run: sudo apt-get install libpq-dev
      - name: Install dependencies
        run: |
          gem install bundler
          bundler install
      - name: Create database
        run: |
          bundler exec rails db:create RAILS_ENV=test
          bundler exec rails db:migrate RAILS_ENV=test
      - name: Run tests
        run: bundler exec rake

• As libpq-dev is a required package to allow the rails application to communicate with Postgres. We added a step to install it using apt-get install libpq-dev.
• To create the database and the tables, we defined the step Create database
• To run the test, we used the command bundler exec rake

At this level, if we run the tests they'll fail. The reason is that we didn't create database service yet. We need to define a new section services inside the rspec-test job.

    services:
      postgres:
        image: postgres:latest
        ports:
        - 5432:5432

• image is the docker image name.
• port maps the local ports to the container's ports.

 rspec-test:
    name: RSpec
    needs: rubocop-test
    runs-on: ubuntu-18.04
    services:
      postgres:
        image: postgres:latest
        ports:
        - 5432:5432
    steps:
      - uses: actions/checkout@v1
...

SampleCov report

Now, we add the following step in order to upload the SimpleCov report from the testing environment and make it available to developers.

      - name: Upload coverage results    
        uses: actions/upload-artifact@master
        if: always()
        with:
          name: coverage-report
          path: coverage

• we are using the action actions/upload-artifact@master to upload the report.
• path is the path of the folder/file to upload
• name is the name of the downloadable file.

If your code passes the tests, you'll be able to download the report from the link in the upper-right corner.

You can check the full code in this link.

References

• https://help.github.com/en/actions/automating-your-workflow-with-github-actions/workflow-syntax-for-github-actions
• https://docs.knapsackpro.com/2019/how-to-run-rspec-on-github-actions-for-ruby-on-rails-app-using-parallel-jobs
• https://jer-k.github.io/github-action-rspec-simplecov/