Create and merge a GH PR automatically

create-gh-pr.sh

#!/usr/bin/env bash
set -euo pipefail

MERGE_WHEN_CHECKS_PASS=0
VIEW_IN_WEB=0

if ! [ -x "$(command -v gh)" ]; then
    echo 'Error: gh is not installed.' >&2
    exit 1
fi

while test $# -gt 0; do
    case "$1" in
    -h | --help)
        echo "create-gh-pr - Create a GitHub PR for the current branch, optionally merging when successful."
        echo " "
        echo "create-gh-pr.sh [options]"
        echo " "
        echo "options:"
        echo "-h, --help                    show brief help"
        echo "-m, --merge-when-checks-pass  merge the PR when all checks pass"
        echo "-w, --view                    open the PR in the web browser when created"
        exit 0
        ;;
    -m | --merge-when-checks-pass)
        MERGE_WHEN_CHECKS_PASS=1
        shift
        ;;
    -w | --view)
        VIEW_IN_WEB=1
        shift
        ;;
    *)
        break
        ;;
    esac
done

pending_or_failed_checks() {
    gh pr checks "$1" | awk -F'\t' '$2 != "pass"' | wc -l
}

# create PR automagically
# TODO: ignore if already exists, instead of failing
gh pr create --fill

PR_NUMBER=$(gh pr list --limit 1 | awk '{ print $1 }')

if [[ "$VIEW_IN_WEB" -eq 1 ]]; then
    gh pr view --web "$PR_NUMBER"
fi

if [[ "$MERGE_WHEN_CHECKS_PASS" -eq 1 ]]; then
    while pending_or_failed_checks "$PR_NUMBER"; do
        sleep 10
    done

    gh pr merge --merge "$PR_NUMBER"
    echo "$PR_NUMBER merged."
fi

One day, GitHub will support git push -o merge_request.create -o merge_request.merge_when_pipeline_succeeds as GitLab does.