Script for removing stale branches

prune_stale.sh

#!/usr/bin/env bash

set -e

candidates=''
stale=''
dry_run=''
review_issues=''

case $1 in
    '--dry-run')
        dry_run='yeppers'
        ;;
    '--review-issues')
        review_issues='yepperooni'
        ;;
    *)
        ;;
esac

function gather_candidates {
    # gather branches that exist on origin
    candidates=$(git branch -a | grep remotes/origin)

    # Exclude branches with version numbers
    candidates=$(printf '%s\n' $candidates | grep -v '\d\.')
    # Splitting the branches on newlines turns
    # "remotes/origin/HEAD -> origin/development" into
    # "remotes/origin/HEAD\n->\ndevelopment", so strip the ->
    candidates=$(printf '%s\n' $candidates | grep -v -- '->')
    # Exclude primary branches
    candidates=$(printf '%s\n' $candidates | grep -Ev 'development|master|HEAD')
    # Strip off the "remotes" prefix
    candidates=$(printf '%s\n' $candidates | sed -E 's| *remotes/origin/||')
}

function gather_stale {
    for branch in $candidates; do
        # look for commits that are on $branch but not on development
        changes=$(git log --oneline "development..origin/$branch")

        if [ -z "$changes" ]; then
            stale="$stale $branch"
        fi
    done
    stale=$(echo $stale | sort)
}

function prune {
    if [ -z $dry_run ]; then
        for branch in $stale; do
            # remove the branch on origin
            git push origin ":$branch" || true
        done
    else
        echo "Would have deleted:"
        for branch in $stale; do
            latest=$(git log -1 --format='%cd' --date=short "origin/$branch")
            echo "$branch (last commit $latest)"
        done
    fi
}

gather_candidates
gather_stale

if [ -z $review_issues ]; then
    prune
else
    issues="$(printf '%s\n' $stale | grep -Eo '^[A-Z]+-\d+')"
    for issue in $issues; do
        open "https://jira.gslabs.us/browse/$issue"
    done
fi