Check commits contain reference to tickets on Bitbucket/Shippable branch

bitbucket-pipelines.yml

pipelines:
  branches:
    *:
    - step:
        script:
           - npm ci
           - npm run lint
           - npm test
           # == Check that all commits since the base branch (dev) contain ACME- for ticket reference ==
           # Fetch the merge base for our project
           - git fetch origin dev:dev
           - >
             echo "-- Checking ACME- prefix on commits --"
             && [[ `git log --oneline dev.. | grep -v 'ACME-' | wc -l` -eq 0 ]]
             && echo "Passed"
             || (echo "Failed for the following commits:"
             && git log --oneline dev.. | grep -v 'ACME-'
             && [[ 0 -eq 1 ]])

This assume that the original repository is a shallow clone (e.g. Bitbucket Pipelines does a --shallow 50 clone of the branch), so we add git fetch origin dev:dev to fetch the merge base (in our case the dev branch) to the local ref dev.