config.yml

version: 2.1
jobs: 
  build: 
    parallelism: 4
    docker: # run the steps with Docker
      - image: circleci/ruby:2.3
        environment: # environment variables for primary container
          BUNDLE_JOBS: 3
          BUNDLE_RETRY: 3
          BUNDLE_PATH: vendor/bundle
          RAILS_ENV: test
    steps: # a collection of executable commands
      - checkout # special step to check out source code to working directory

      # Which version of bundler?
      - run:
          name: Which bundler?
          command: bundle -v

      # Restore bundle cache
      # Read about caching dependencies: https://circleci.com/docs/2.0/caching/
      - restore_cache:
          keys:
            - rocket-library-{{ checksum "Gemfile.lock" }}
            - rocket-library-

      - run: # Install Ruby dependencies
          name: Bundle Install
          command: bundle check --path vendor/bundle || bundle install --deployment

      # Store bundle cache for Ruby dependencies
      - save_cache:
          key: rrocket-library-{{ checksum "Gemfile.lock" }}
          paths:
            - vendor/bundle

      - run:
          name: Run rspec in parallel
          command: |
            bundle exec rspec --profile 10 \
                              --format JUnit \
                              --out $CIRCLE_TEST_REPORTS/rspec.xml \
                              --format progress \
                              $(circleci tests glob "spec/**/*_spec.rb" | circleci tests split --split-by=timings)

      # Save test results for timing analysis
      - store_test_results: # Upload test results for display in Test Summary: https://circleci.com/docs/2.0/collect-test-data/
          path: $CIRCLE_TEST_REPORTS