Add appraisal to a rubygem project

Appraisals is a tool to generate different Gemfiles so you can do matrix testing (e.g. different versions of ruby).

How to add appraisal to your project

1. Add the appraisal to the group development from the Gemfile

bundle add appraisal --skip-install --group development

1. Run bundle install to install the dependencies.

bundle install

1. Create a Appraisals file on root of the project.

# frozen_string_literal: true

SUPPORTED_VERSIONS = %w[3.8 3.9 4.0 4.1].freeze

SUPPORTED_VERSIONS.each do |version|
  appraise "jekyll-#{version}" do
    gem 'jekyll', version
  end
end

1. Generate the Gemfiles in the folder ‘gemfiles’

bundle exec appraisal generate

1. Create a ci.yml in the folder ‘.github/workflows’

name: CI
on: 
  push:
    branches:
      - "*"
    tags-ignore:
      - "*"
  pull_request:
    branches:
      - "*"
    tags-ignore:
      - "*"
jobs:  
  build:
    strategy:
      matrix:
        ruby: [2.4, 2.5, 2.6, 2.7]
        gemfile:
          - gemfiles/jekyll_3.8.gemfile
          - gemfiles/jekyll_3.9.gemfile
          - gemfiles/jekyll_4.0.gemfile
          - gemfiles/jekyll_4.1.gemfile
        exclude:
        - ruby: 2.4
          gemfile: gemfiles/jekyll_4.0.gemfile
        - ruby: 2.4
          gemfile: gemfiles/jekyll_4.1.gemfile
        - ruby: 2.5
          gemfile: gemfiles/jekyll_4.0.gemfile
        - ruby: 2.5
          gemfile: gemfiles/jekyll_4.1.gemfile
    env:
      BUNDLE_GEMFILE: $
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Set up Ruby $
      uses: actions/setup-ruby@v1
      with:
        ruby-version: $
    - name: bundle install
      run: |
        gem install bundler
        bundle install --jobs 4 --retry 3
    - name: Run Test
      run: bundle exec rake test