language: ruby
cache: bundler

# For ruby compatibility, we test the highest and lowest minor versions only.
# For example, if our gemspec says `required_ruby_version = ">= 2.3.0"`, and
# ruby 2.5.0 has just been released, then we test 2.3 and 2.5, but not 2.4.
rvm:
  - 2.3.8
  - 2.4.5
  - 2.5.3

env:
  global:
    - TRAVIS=true

# We want to use `sudo: false` because the container infrastructure is supposed
# to be faster, but Travis is having issues with containers lately ..
#
# > No output has been received in the last 10m0s
#
# .. and they recommend we use the VM infrastructure (`sudo: required`) in
# the meantime.
sudo: required

before_install:
  - gem update bundler

gemfile:
  - gemfiles/ar_4.2.gemfile
  - gemfiles/ar_5.1.gemfile
  - gemfiles/ar_5.2.gemfile
matrix:
  exclude:
    # optimization: don't test intermediate rubies (see above)
    - rvm: 2.4.5
      gemfile: gemfiles/ar_4.2.gemfile
    - rvm: 2.4.5
      gemfile: gemfiles/ar_5.1.gemfile
    - rvm: 2.4.5
      gemfile: gemfiles/ar_5.2.gemfile
  fast_finish: true