Update all branches of repo (includes filter)

update-all-branches.sh

#!/bin/bash

# Merges the ${BASE} branch into all other branches
#
# Process:
#
#   - Save the name of the current branch
#   - If the current branch is not ${BASE} then checkout ${BASE}.
#   - Pull the latest changes for ${BASE} from its upstream branch.
#   - Loop over each remote branch.
#     - If the branch is not ${BASE}.
#       - Checkout the branch.
#       - Merge ${BASE} into the branch.
#       - Push changes if no conflicts
#   - If the current branch is not the saved branch name checkout the saved
#     branch name

DIRECTORY=$(pwd)
BASE="master"
FILTER="feature"

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -d|--dir|--directory)
    DIRECTORY="$2"
    shift # past argument
    shift # past value
    ;;

    -b|--base)
    BASE="$2"
    shift # past argument
    shift # past value
    ;;

    -f|--filter)
    FILTER="$2"
    shift # past argument
    shift # past value
    ;;

    *)    # unknown option
    POSITIONAL+=("$1") # save it in an array for later
    shift # past argument
    ;;
esac
done

set -- "${POSITIONAL[@]}" # restore positional parameters

cd "${DIRECTORY}" || exit 1

REMOTE_BRANCHES=$(git for-each-ref --format="%(refname:lstrip=3)" refs/remotes/origin/${FILTER})

# Returns the name of the current branch
current_branch() {
    git symbolic-ref --short HEAD
}

STARTING_BRANCH=$(current_branch)

if [[ "${STARTING_BRANCH}" != "${BASE}" ]]; then
    echo "Swapping to base branch"
    git checkout "${BASE}" -q
fi

git pull -q

for BRANCH in ${REMOTE_BRANCHES}; do
    if [[ "${BRANCH}" != "${BASE}" ]]; then
        echo "Updating: ${BRANCH}"

        git reset --hard -q
        git checkout "${BRANCH}" -f -q
        git pull -q
        git merge "${BASE}" -q

        if git diff --check -q; then
            git push --progress -q
        fi
    fi
done

echo

if [[ "${STARTING_BRANCH}" != "$(current_branch)" ]]; then
    echo "Returning to starting branch"
    git checkout "${STARTING_BRANCH}"
fi