language: ruby
cache: bundler
rvm:
- 2.5
- 2.4
gemfile:
- gemfiles/rails_52.gemfile
- gemfiles/rails_51.gemfile
matrix:
  include:
  # old rails
  - rvm: 2.5
    gemfile: gemfiles/rails_50.gemfile
  - rvm: 2.5
    gemfile: gemfiles/rails_42.gemfile
  # old rubies
  - rvm: 2.3
    gemfile: gemfiles/rails_52.gemfile
  # future rails
  - rvm: 2.5
    gemfile: gemfiles/rails_60.gemfile
  # Allow rails 6 to fail while master branch is used
  allow_failures:
  - rvm: 2.5
    gemfile: gemfiles/rails_60.gemfile
notifications:
  email: false

# for 2.5.0 until 2.5.1 is released:
#   https://github.com/travis-ci/travis-ci/issues/8978
#   https://github.com/travis-ci/travis-ci/issues/8969#issuecomment-354135622
before_install:
  - gem update --system
  - gem install bundler