It connects on circle and look for repeated builds in the same branch. It cancel the old builds keeping only latest commit in each branch.

It doesn't cancel builds on master branch.

1. Create or get your key on Circle CI api.
2. Set your environment variable on a .env file in the main directory of these project

I recommend you to use .env with the following keys.

CI_TOKEN=myAwesomeToken
CI_REPOSITORY="ideia.me"
CI_USERNAME="jonatas"

ruby ./avoid-double-build-on-branch.rb

Create the repo on heroku:

heroku create

Setup your keys on heroku:

heroku config:set CI_TOKEN=myAwesomeToken \
  CI_REPOSITORY="ideia.me" \
  CI_USERNAME="jonatas"

heroku run ruby ./avoid-double-build-on-branch.rb

If it works like in heroku via heroku run, configure it to heroku scheduler.

Setup the Heroku Scheduler

heroku addons:create scheduler:standard

Configure it via web:

heroku addons:open scheduler

Click on "Add Job..."

After that, fill on "run command" input field:

ruby ./avoid-double-build-on-branch.rb

Configure it to run each 10 minutes.