index.js

let drone = require('./utils/drone')
// platform denotes code hosting provider i.e github, gitlab, bitbucket etc.
// Had to introduce this variable as there are cases when CI is run on the same platform where code is hosted as those cases need to be handled differently.
// Default value is github
let platform = 'github';
let repo, sha, event, commit_message, pull_request_number, branch, ci, jobUrl, buildUrl

if (process.env.TRAVIS) {
  // Reference: https://docs.travis-ci.com/user/environment-variables

  repo = process.env.TRAVIS_REPO_SLUG
  sha = process.env.TRAVIS_PULL_REQUEST_SHA || process.env.TRAVIS_COMMIT
  event = process.env.TRAVIS_EVENT_TYPE
  commit_message = process.env.TRAVIS_COMMIT_MESSAGE
  pull_request_number = process.env.TRAVIS_PULL_REQUEST
  jobUrl = `https://travis-ci.org/${repo}/jobs/${process.env.TRAVIS_JOB_ID}`
  buildUrl = `https://travis-ci.org/${repo}/builds/${process.env.TRAVIS_JOB_ID}`

  branch =
    process.env.TRAVIS_EVENT_TYPE === 'push'
      ? process.env.TRAVIS_BRANCH
      : process.env.TRAVIS_PULL_REQUEST_BRANCH

  ci = 'travis'
} else if (process.env.CIRCLECI) {
  // Reference: https://circleci.com/docs/1.0/environment-variables

  repo = process.env.CIRCLE_PROJECT_USERNAME + '/' + process.env.CIRCLE_PROJECT_REPONAME

  sha = process.env.CIRCLE_SHA1
  event = 'push'
  commit_message = '' // circle does not expose commit message
  if (process.env.CI_PULL_REQUEST) {
    pull_request_number = process.env.CI_PULL_REQUEST.split('/').pop() // take number from returns url
    event = 'pull_request'
  } else pull_request_number = ''
  branch = process.env.CIRCLE_BRANCH
  ci = 'circle'
} else if (process.env.WERCKER) {
  // Reference: https://devcenter.wercker.com/docs/environment-variables/available-env-vars

  repo = process.env.WERCKER_GIT_OWNER + '/' + process.env.WERCKER_GIT_REPOSITORY

  sha = process.env.WERCKER_GIT_COMMIT
  event = 'push'
  commit_message = '' // wercker does not expose commit message
  pull_request_number = '' // wercker does not expose pull request number
  branch = process.env.WERCKER_GIT_BRANCH
  ci = 'wercker'
} else if (process.env.DRONE) {
  // Reference: http://readme.drone.io/usage/environment-reference

  repo = process.env.DRONE_REPO || process.env.CI_REPO || drone.getLegacyRepo(process.env)
  sha = process.env.DRONE_COMMIT || process.env.CI_COMMIT
  // DRONE_BUILD_EVENT available in drone > v0.5
  // DRONE_EVENT, CI_EVENT available in drone < v0.5
  // no EVENT available in drone < v0.4
  event = process.env.DRONE_BUILD_EVENT || process.env.DRONE_EVENT || process.env.CI_EVENT || 'push'
  commit_message = '' // drone does not expose commit message
  pull_request_number = process.env.DRONE_PULL_REQUEST
  branch = process.env.DRONE_BRANCH || process.env.CI_BRANCH
  ci = 'drone'
} else if (process.env.GITLAB_CI){
  // Reference: https://docs.gitlab.com/ee/ci/variables/predefined_variables.html
  // except buildUrl we get all the other variables for gitlab CI
  repo = process.env.CI_PROJECT_PATH
  branch = process.env.CI_COMMIT_REF_NAME
  commit_message = process.env.CI_COMMIT_MESSAGE
  pull_request_number = (process.env.CI_MERGE_REQUEST_ID || '') // no pull request numnber in case the CI is run for the branch without a pull request
  sha=process.env.CI_COMMIT_SHA
  event = process.env.CI_PIPELINE_SOURCE
  jobUrl = process.env.CI_JOB_URL
  platform = 'gitlab'
  ci = 'gitlab'
} else if (process.env.CI_NAME === 'codeship') {
  // Reference: https://documentation.codeship.com/basic/builds-and-configuration/set-environment-variables/#default-environment-variables

  repo = process.env.CI_REPO_NAME
  branch = process.env.CI_BRANCH
  commit_message = process.env.CI_COMMIT_MESSAGE || process.env.CI_MESSAGE

  event = 'push'
  pull_request_number = process.env.CI_PR_NUMBER
  sha=process.env.CI_COMMIT_ID,
  buildUrl=process.env.CI_BUILD_URL

  ci = 'codeship'
} else if (process.env.GITHUB_ACTION) {
  // GitHub Actions
  // Reference: https://developer.github.com/actions/creating-github-actions/accessing-the-runtime-environment/
  
  // for pull_request event, GITHUB_REF is of the form refs/pull/<pull_request_number>/merge
  // for push event, GITHUB_REF is of the form refs/heads/<branch>
  
  const pull_request_numberORbranch=process.env.GITHUB_REF.split('/')[2];

  repo = process.env.GITHUB_REPOSITORY
  sha = process.env.GITHUB_SHA
  event = process.env.GITHUB_EVENT_NAME
  commit_message = ''
  pull_request_number = event==='pull_request'? pull_request_numberORbranch:''
  // GITHUB_HEAD_REF for pull requests. For commits, GITHUB_REF is of the form refs/heads/master, for example
  branch = event ==='pull_request'? process.env.GITHUB_HEAD_REF : pull_request_numberORbranch
  ci = 'github_actions'
} else if (process.env.NETLIFY) {
  // Reference: https://www.netlify.com/docs/continuous-deployment/#environment-variables
  repo = process.env.REPOSITORY_URL.split('@github.com/').pop()
  event = process.env.PULL_REQUEST?'pull_request':'push'
  pull_request_number = process.env.PULL_REQUEST?process.env.REVIEW_ID:''
  sha = process.env.COMMIT_REF
  branch = process.env.HEAD
  ci = 'netlify'
} else if (process.env.NOW_GITHUB_ORG) {
  // Reference: https://zeit.co/docs/v2/advanced/now-for-github/
  repo = process.env.NOW_GITHUB_ORG + '/' + process.env.NOW_GITHUB_REPO
  event = 'push'
  pull_request_number = ''
  sha = process.env.NOW_GITHUB_COMMIT_SHA
  branch = process.env.NOW_GITHUB_COMMIT_REF
  ci = 'now'
} else if (process.env.CI) {
  // Generic variables for docker images, custom CI builds, etc.

  repo = process.env.CI_REPO_OWNER + '/' + process.env.CI_REPO_NAME

  sha = process.env.CI_COMMIT_SHA
  event = process.env.CI_EVENT || 'push'
  commit_message = process.env.CI_COMMIT_MESSAGE
  pull_request_number = process.env.CI_MERGE_REQUEST_ID
  branch = process.env.CI_BRANCH
  ci = 'custom'
}

module.exports = { repo, sha, event, commit_message, branch, pull_request_number, ci, platform, jobUrl, buildUrl }