A sample GitLab CI configuration file for building, testing and deploying a JavaScript based project to Heroku

.gitlab-ci.yml

# This file is a template, and might need editing before it works on your project.
# Official framework image. Look for the different tagged releases at:
# https://hub.docker.com/r/library/node/tags/
image: node:12.10.0

# This folder is cached between builds
# http://docs.gitlab.com/ce/ci/yaml/README.html#cache
cache:
  paths:
  - node_modules/

stages:
  - build
  - deploy

build and test:
  stage: build
  script:
   - npm ci
   - npm run build
   - npm run test

deployment:
  stage: deploy
  only:
   - master
  script:
    - echo $GITLAB_USER_NAME has started a release
    - echo "Last commit $CI_COMMIT_MESSAGE"
    - git remote add heroku https://heroku:$MY_HEROKU_API_KEY@git.heroku.com/<MY_APP>.git
    - git push -q heroku HEAD:master
    # Optional: check health check. See my post: https://medium.com/better-programming/how-to-add-a-health-check-to-your-node-js-app-5154d13b969e
    - echo Checking health check after deployment to verify server is running
    - curl 'https://<my_app>.herokuapp.com/healthcheck' --compressed --fail --head --retry 5