Push commit to Github and open/update a PR

git-pr-update.sh

#!/usr/bin/env bash

set -euo pipefail

KEY="Change-Id: "
SOURCE_REMOTE=origin
TARGET_USER=$(git remote get-url "$SOURCE_REMOTE" | sed 's/^.*\.com[:/]\(.*\)\/.*$/\1/')

TARGET_REMOTE="${TARGET_REMOTE:-origin}"
if git rev-parse --verify main >/dev/null 2>&1; then
    DEFAULT_TARGET_BRANCH="main"
else
    DEFAULT_TARGET_BRANCH="master"
fi
TARGET_BRANCH="${TARGET_BRANCH:-${DEFAULT_TARGET_BRANCH}}"


function merge_base() {
    git fetch "${TARGET_REMOTE}"
    git merge-base "${TARGET_REMOTE}/${TARGET_BRANCH}" $1
}

function commit_summary() {
  git show --no-patch --format=%s $1
}

function commit_body() {
  git show --no-patch --format=%b $1
}

function pr_branch() {
  offset=$((${#KEY} + 1))
  commit_body $1 | grep -E "^$KEY" | cut -c ${offset}-
}


to=${2:-HEAD}
from=${1:-$(merge_base ${to})}

tail=$(git rev-parse $from)
head=$(git rev-parse $to)

git merge-base --is-ancestor $tail $head

repo=$(git rev-parse --show-toplevel)

commits=($(git rev-list --ancestry-path ${tail}..${head} | tac))

for commit in "${commits[@]}"; do
  if ! pr_branch $commit >/dev/null ; then
    echo "Sorry but commit $commit is missing \`$KEY\`"
    echo ""
    echo "Try installing the Gerrit Git commit message hook and then amending your commits:"
    echo ""
    echo " (cd ${repo} && f=`git rev-parse --git-dir`/hooks/commit-msg ; mkdir -p \$(dirname \$f) ; curl -Lo \$f https://gerrit-review.googlesource.com/tools/hooks/commit-msg ; chmod +x \$f)"
    echo ""

    exit 1
  fi
done

remotes=()
for commit in "${commits[@]}"; do
  remotes+=("${commit}:refs/heads/$(pr_branch $commit)")
done
git push $SOURCE_REMOTE --force-with-lease "${remotes[@]}"

if command -v gh >/dev/null; then
  i=0
  for commit in "${commits[@]}"; do
    pr=$(pr_branch $commit)
    base=$( [[ $i -eq 0 ]] && echo "$TARGET_BRANCH" || echo "$(pr_branch ${commits[((i - 1))]})" )
    count=$(gh pr list --state all --head "$pr" --json id --jq length)

    if [[ "$count" -gt 1 ]]; then
        echo "Sorry I don't know which PR to update."
        echo "There are multiple PRs with the same --head $pr"
        gh pr list --state all --head "$pr"
        exit 1
    fi

    #&& [[ $(gh pr list --state all --search "$pr" | wc -l) -eq 0 ]]
    if [[ "$count" -eq 0 ]]; then
        gh pr create \
           --base "$base" \
           --head "${TARGET_USER}:${pr}" \
           --title "$(commit_summary $commit)" \
           --body  "$(commit_body $commit)"
    fi

    gh pr edit "${pr}" \
       --base "$base" \
       --title "$(commit_summary $commit)" \
       --body  "$(commit_body $commit)" || true

    if [[ -f ".pr-update.$i.sh" ]]; then
        bash ".pr-update.$i.sh" "$pr"
    fi

    ((++i))
  done
fi

echo "🔥🔥🔥🔥🔥"
echo "Done! 🦙🚀"