git-delete-merged - delete local branches that have been merged on GitHub

git-delete-merged

#!/bin/sh
#
# git-delete-merged - delete local branches that have been merged on GitHub
#
# Copyright (c) 2022 Akinori MUSHA
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

main () {
    set -e

    url="$(gh browse -n)"
    case "$url" in
        https://github.com/*/*)
            path=${url#https://github.com/}
            owner=${path%/*}
            repo=${path#*/}
            ;;
        *)
            echo Not a GitHub project. >&2
            exit
    esac

    setup

    gh api graphql -f query='query ($owner: String!, $repo: String!) {
      repository(owner: $owner, name: $repo) {
        pullRequests(
          states: [MERGED]
          orderBy: {field: UPDATED_AT, direction: DESC}
          first: 100
        ) {
          nodes {
            headRefName
            headRefOid
            baseRefName
          }
        }
      }
    }' -f owner="$owner" -f repo="$repo" \
       --jq '.data.repository.pullRequests.nodes | map("\(.headRefName) \(.headRefOid) \(.baseRefName)") | join("\n")' > "$MYTMPDIR"/merged

    git branch --format="%(refname:lstrip=2) %(objectname)" | sort > "$MYTMPDIR"/locals

    current="$(git rev-parse --abbrev-ref HEAD)"

    cut -d' ' -f1,2 "$MYTMPDIR"/merged | sort -u | comm -12 - "$MYTMPDIR"/locals | while read branch sha; do
        base="$(awk -v branch="$branch" '$1 == branch { print $2 }' "$MYTMPDIR"/merged)"
        echo "$branch has been merged into $base." >&2
        if [ "$branch" = "$current" ]; then
            if git checkout "$base" && git pull --ff; then
                git br -D "$branch"
            fi
        else
            git br -D "$branch"
        fi
    done

    teardown
}

setup () {
    MYTMPDIR=$(mktemp -d "${TMPDIR-/tmp}/${0##*/}.XXXXXX")
    trap 'teardown; exit 129' 1
    trap 'teardown; exit 130' 2
    trap 'teardown; exit 131' 3
    trap 'teardown; exit 143' 15
}

teardown () {
    rm -rf "$MYTMPDIR"
}

main "$@"