entrypoint-separate-branch.sh

#!/usr/bin/env bash

set -e
set -o pipefail

if [[ -z "$GITHUB_TOKEN" ]]; then
  echo "Set the GITHUB_TOKEN environment variable."
  exit 1
fi

if [[ ! -z "$INPUT_SOURCE_BRANCH" ]]; then
  SOURCE_BRANCH="$INPUT_SOURCE_BRANCH"
elif [[ ! -z "$GITHUB_REF" ]]; then
  SOURCE_BRANCH=${GITHUB_REF/refs\/heads\//}  # Remove branch prefix
else
  echo "Set the INPUT_SOURCE_BRANCH environment variable or trigger from a branch."
  exit 1
fi

echo "********************************************************************************"
echo "Git Version: $(git --version)"
echo "********************************************************************************"
echo "git config"
AUTHOR_EMAIL=$(cat "$GITHUB_EVENT_PATH" | jq '.head_commit.author.email' | sed 's/"//g')
git config --global user.name "$GITHUB_ACTOR"
git config --global user.email "$AUTHOR_EMAIL"
git config --list
echo "********************************************************************************"

DESTINATION_BRANCH="${INPUT_DESTINATION_BRANCH:-"master"}"

# Fix for the unsafe repo error: https://github.com/repo-sync/pull-request/issues/84
git config --global --add safe.directory /github/workspace

# Github actions no longer auto set the username and GITHUB_TOKEN
git remote set-url origin "https://$GITHUB_ACTOR:$GITHUB_TOKEN@${GITHUB_SERVER_URL#https://}/$GITHUB_REPOSITORY"
git remote -v

# Pull all branches references down locally so subsequent commands can see them
git fetch origin '+refs/heads/*:refs/heads/*' --update-head-ok

# Print out all branches
git --no-pager branch -a -vv

if [ "$(git rev-parse --revs-only "$SOURCE_BRANCH")" = "$(git rev-parse --revs-only "$DESTINATION_BRANCH")" ]; then
  echo "Source and destination branches are the same."
  exit 0
fi

# Do not proceed if there are no file differences, this avoids PRs with just a merge commit and no content
LINES_CHANGED=$(git diff --name-only "$DESTINATION_BRANCH" "$SOURCE_BRANCH" -- | wc -l | awk '{print $1}')
if [[ "$LINES_CHANGED" = "0" ]] && [[ ! "$INPUT_PR_ALLOW_EMPTY" ==  "true" ]]; then
  echo "No file changes detected between source and destination branches."
  exit 0
fi

# Create a new branch for the PR based on the original source branch
MERGE_BRANCH="${INPUT_PR_MERGE_BRANCH:-"merge-branch"}"

echo "Creating a new branch for the PR: $MERGE_BRANCH"
echo "Original Source branch: $SOURCE_BRANCH"
echo "Original Destination branch: $DESTINATION_BRANCH"

git branch -D "$MERGE_BRANCH" || true

git fetch origin
git checkout -b $MERGE_BRANCH origin/$SOURCE_BRANCH

git status

# Change the upstream branch to the destination branch
git branch -u origin/$DESTINATION_BRANCH
git status

echo "Commits to be rebased:"
git log origin/$DESTINATION_BRANCH..HEAD --oneline

# Rebase the new source branch onto the destination branch
REBASE_STRATEGY="${INPUT_PR_REBASE_STRAT:-""}"
echo "Running Command: git rebase ${REBASE_STRATEGY}"
git rebase ${REBASE_STRATEGY} || true

# Immediately abort. We cannot automatically continue rebasing if there are conflicts.
git rebase --abort || true

git push origin $MERGE_BRANCH -f

# Workaround for `hub` auth error https://github.com/github/hub/issues/2149#issuecomment-513214342
export GITHUB_USER="$GITHUB_ACTOR"

PR_ARG="$INPUT_PR_TITLE"
if [[ ! -z "$PR_ARG" ]]; then
  PR_ARG="-m \"$PR_ARG\""

  if [[ ! -z "$INPUT_PR_TEMPLATE" ]]; then
    sed -i 's/`/\\`/g; s/\$/\\\$/g' "$INPUT_PR_TEMPLATE"
    PR_ARG="$PR_ARG -m \"$(echo -e "$(cat "$INPUT_PR_TEMPLATE")")\""
  elif [[ ! -z "$INPUT_PR_BODY" ]]; then
    PR_ARG="$PR_ARG -m \"$INPUT_PR_BODY\""
  fi
fi

if [[ ! -z "$INPUT_PR_REVIEWER" ]]; then
  PR_ARG="$PR_ARG -r \"$INPUT_PR_REVIEWER\""
fi

if [[ ! -z "$INPUT_PR_ASSIGNEE" ]]; then
  PR_ARG="$PR_ARG -a \"$INPUT_PR_ASSIGNEE\""
fi

if [[ ! -z "$INPUT_PR_LABEL" ]]; then
  PR_ARG="$PR_ARG -l \"$INPUT_PR_LABEL\""
fi

if [[ ! -z "$INPUT_PR_MILESTONE" ]]; then
  PR_ARG="$PR_ARG -M \"$INPUT_PR_MILESTONE\""
fi

if [[ "$INPUT_PR_DRAFT" ==  "true" ]]; then
  PR_ARG="$PR_ARG -d"
fi

COMMAND="hub pull-request \
  -b $DESTINATION_BRANCH \
  -h $MERGE_BRANCH \
  --no-edit \
  $PR_ARG \
  || true"

echo "$COMMAND"

PR_URL=$(sh -c "$COMMAND")
if [[ "$?" != "0" ]]; then
  exit 1
fi

echo ${PR_URL}
echo "::set-output name=pr_url::${PR_URL}"
echo "::set-output name=pr_number::${PR_URL##*/}"
if [[ "$LINES_CHANGED" = "0" ]]; then
  echo "::set-output name=has_changed_files::false"
else
  echo "::set-output name=has_changed_files::true"
fi