quimby.sh

#!/bin/bash

# Author: nasamuffin
#
# Usage:
#
#   quimby <base-branch> <topic-branch> [-C <path>] [args-to-format-patch...]
#
# When you invoke 'quimby' against your topic, it does the following things:
#
# 1) Pushes (by force if necessary) <topic-branch> and <base-branch> to your
#    fork of Git on Github.
# 2) Calls 'git-format-patch' with the provided flags, plus --cover-letter if
#    more than one commit will exist.
#
# quimby must be run from inside a repo, or a repo must be specified with -C.
#
# You must set a Git config "quimby.fork" to contain the name of your fork of
# Git. This can take the form either of a previously configured remote, or a
# URL, as it will be passed directly to 'git push'.
#
#
# Some notes:
#
# - Actions will only be run if <base-branch>..<topic-branch> contains
#   dd/ci-swap-azure-pipelines-with-github-actions. That topic was merged to
#   'master' on April 29, 2020 (8cb514d1cb), but an older version of 'master'
#   may not run tests. Use an earlier commit of 'quimby' to get the GitGitGadget
#   PR workflow instead if your <base-branch> is that old.
# - <topic-branch> will be force-pushed to your own fork. If you're using quimby
#   because your usual workflow doesn't use Github at all, that shouldn't bother
#   you.

# Positional parameters
PARAMS=()

git_dir=
version=
mail_dir=

# We gather the configs first, so that we can override them from the command
# line if necessary.

# Check if we have a remote set up.
remote="$(git ${git_dir} config quimby.fork)"
while [[ -z "${remote}" ]]; do
  git ${git_dir} remote -v
  echo "quimby.fork is not configured. Please provide a remote name or URL:"
  read remote
  git ${git_dir} config quimby.fork "${remote}"
done

# Check if we have a maildir set up.
mail_dir="$(git ${git_dir} config quimby.maildir)"
if [[ "${mail_dir}" ]]; then mail_dir="-o ${mail_dir/#\~/$HOME}"; fi

# Check for args
while (( "$#" )); do
  case "$1" in
    -C)
      git_dir="-C '$2'"
      shift 2
      ;;
    -o)
      mail_dir="-o $2"
      shift 2
      ;;
    -v*)
      # take everything but the dash
      version="${1#-v}"
      shift
      ;;
    *)
      PARAMS+=("$1")
      shift
      ;;
  esac
done

# Infer the relevant branches if not specified
if [[ "${#PARAMS[@]}" -lt 2 ]];
then
  base_branch="$(git ${git_dir} rev-parse --abbrev-ref HEAD@{u})"
  topic_branch="$(git ${git_dir} rev-parse --abbrev-ref HEAD)"
  exit
else
  base_branch="${PARAMS[0]}"
  topic_branch="${PARAMS[1]}"
  PARAMS=(${PARAMS[@]:2})
fi

# Save a copy.
# Since this isn't ML-visible, explicitly note v1 (this will help our math for
# v2)
save_branch="QUIMBY--${topic_branch}--v${version:-1}"
git branch --force ${save_branch} ${topic_branch}
echo "Saved mailed state into '${save_branch}'"

# Generate an interdiff if we had a copy of n-1
rangediff_flag=
prev_branch="QUIMBY--${topic_branch}--v$((${version}-1))"
if [[ "$(git show-ref "${prev_branch}")" ]];
then
  rangediff_flag="--range-diff=${prev_branch}"
  echo "including a range-diff from ${prev_branch}"
fi

# Force push to start an Actions run:
git ${git_dir} push "${remote}" "${base_branch}" +"${topic_branch}"
echo "Check the Actions tab on your fork to monitor the CI run."
echo "Maybe at https://github.com/${remote}/git/actions?query=branch%3A${topic_branch}++"

# Determine whether a cover letter is needed
cover_letter_flag=
if [[ "$(git rev-list --count "${base_branch}..${topic_branch}")" -gt 1 ]];
then
  cover_letter_flag="--cover-letter"
fi

# Break out version flag; it should be excluded if v1.
version_flag=
if [[ "${version}" ]];
then
  version_flag="-v${version}"
fi

git format-patch ${cover_letter_flag} ${rangediff_flag} \
  ${mail_dir}/${topic_branch}/v${version:-1} \
  ${version_flag} "${PARAMS[@]}" \
  "${base_branch}..${topic_branch}"