git-refresh

#!/usr/bin/env bash
#
# Lives here: https://gist.github.com/datashaman/0dd6d294c68a16181141d9c41285e9fb
#
# Refresh your working copy branches. Assumes that you have a source
# repository on _origin_ remote, and a fork on _$GIT_REFRESH_REMOTE_ remote.
#
# Required .env variables:
#     GIT_REFRESH_REMOTE - set to the remote name for your fork.
#
# Optional .env variables:
#     GIT_REFRESH_BASE - set to your base branch, defaults to master. Don't use origin.
#     GIT_REFRESH_INTERACTIVE - Set to true if you want to rebase interactively. Doesn't check if rebase is necessary.
#     GIT_REFRESH_PUSH - Set to true if you want to push to your fork during the refresh.
#
# It does as little work as possible to get a complete set of refreshed
# local branches.
#
# Steps:
#
# - Update remote branches (with prune)
# - Remove any local merged branches whose remote has disappeared
# - For each local branch:
#     - Check hashes to see if rebase is necessary
#     - If interactive or rebase is necessary:
#         - Perform rebase on origin/$GIT_REFRESH_BASE
#         - If the upstream is origin/$GIT_REFRESH_BASE:
#             - If the branch is $GIT_REFRESH_BASE:
#                 - Push it to your fork
#             - Else:
#                 - Push it to your fork and set upstream (new branch)
#         - Else:
#             - Force push (with lease) if necessary to your fork
#     - Else:
#         - Force push (with lease) if necessary to your fork

set -e

function maybe_push_branch ()
{
    LOCAL_HASH=$(git rev-parse $REFNAME)
    UPSTREAM_HASH=$(git rev-parse $UPSTREAM)

    if [ "$LOCAL_HASH" != "$UPSTREAM_HASH" ]; then
        git push --force-with-lease $GIT_REFRESH_REMOTE $REFNAME
    fi
}

function push_rebase ()
{
    if [ "$UPSTREAM" == "origin/$GIT_REFRESH_BASE" ]; then
        if [ "$REFNAME" == "$GIT_REFRESH_BASE" ]; then
            git push $GIT_REFRESH_REMOTE $REFNAME
        else
            git push -u $GIT_REFRESH_REMOTE $REFNAME
        fi
    else
        maybe_push_branch
    fi
}

function refresh_branch ()
{
    ORIGIN_HASH=$(git rev-parse origin/$GIT_REFRESH_BASE)
    BASE_HASH=$(git merge-base $GIT_REFRESH_BASE $REFNAME)

    if [ "$GIT_REFRESH_INTERACTIVE" == "true" -o "$ORIGIN_HASH" != "$BASE_HASH" ]; then
        git rebase $($GIT_REFRESH_INTERACTIVE && echo -i) origin/$GIT_REFRESH_BASE $REFNAME
        $GIT_REFRESH_PUSH && push_rebase
    else
        $GIT_REFRESH_PUSH && maybe_push_branch
    fi
}

function usage ()
{
cat <<EOF
Usage: ${0##*/} [-h] [-i] [-p]

refresh git branches

    -h          display this help and exit
    -i          rebase branches interactively
    -p          push to the fork during refresh
EOF
}

GIT_REFRESH_BASE=master
GIT_REFRESH_INTERACTIVE=false
GIT_REFRESH_PUSH=false
export HUSKY_IGNORE=true

source .env

OPTIND=1

while getopts "hip" opt
do
    case "${opt}" in
        h)
            usage
            exit 0
            ;;
        i)
            GIT_REFRESH_INTERACTIVE=true
            ;;
        p)
            GIT_REFRESH_PUSH=true
            ;;
        *)
            usage
            exit 0
            ;;
    esac
done

shift "$((OPTIND-1))"

if [ -z "$GIT_REFRESH_REMOTE" ]; then
    echo "Please set GIT_REFRESH_REMOTE in .env"
    exit 1
fi

git remote update -p origin $GIT_REFRESH_REMOTE

CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)

git checkout master
git branch -vv | grep ' gone' | cut -d' ' -f3 | xargs -r branch -d

BRANCHES=$(git for-each-ref --format='%(refname:short),%(upstream:short)' refs/heads/)

for BRANCH in $BRANCHES
do
    REFNAME=${BRANCH%,*}
    UPSTREAM=${BRANCH#*,}

    refresh_branch $REFNAME $UPSTREAM
done

git checkout $CURRENT_BRANCH