entrypoint.sh

#!/bin/bash

set -e

PR_NUMBER=$(jq --raw-output .pull_request.number "$GITHUB_EVENT_PATH")
echo "Collecting information about PR #$PR_NUMBER of $GITHUB_REPOSITORY..."

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

URI=https://api.github.com
API_HEADER="Accept: application/vnd.github.v3+json"
AUTH_HEADER="Authorization: token $GITHUB_TOKEN"

pr_resp=$(curl -X GET -s -H "${AUTH_HEADER}" -H "${API_HEADER}" \
          "${URI}/repos/$GITHUB_REPOSITORY/pulls/$PR_NUMBER")

BASE_REPO=$(echo "$pr_resp" | jq -r .base.repo.full_name)
BASE_BRANCH=$(echo "$pr_resp" | jq -r .base.ref)

if [[ -z "$BASE_BRANCH" ]]; then
	echo "Cannot get base branch information for PR #$PR_NUMBER!"
	echo "API response: $pr_resp"
	exit 1
fi

USER_LOGIN=$(jq -r ".comment.user.login" "$GITHUB_EVENT_PATH")

user_resp=$(curl -X GET -s -H "${AUTH_HEADER}" -H "${API_HEADER}" \
            "${URI}/users/${USER_LOGIN}")

USER_NAME=$(echo "$user_resp" | jq -r ".name")
if [[ "$USER_NAME" == "null" ]]; then
	USER_NAME=$USER_LOGIN
fi
USER_NAME="${USER_NAME} (Rebase PR Action)"

USER_EMAIL=$(echo "$user_resp" | jq -r ".email")
if [[ "$USER_EMAIL" == "null" ]]; then
	USER_EMAIL="$USER_LOGIN@users.noreply.github.com"
fi


HEAD_REPO=$(echo "$pr_resp" | jq -r .head.repo.full_name)
HEAD_BRANCH=$(echo "$pr_resp" | jq -r .head.ref)

echo "Base branch for PR #$PR_NUMBER is $BASE_BRANCH"

USER_TOKEN=${USER_LOGIN}_TOKEN
COMMITTER_TOKEN=${!USER_TOKEN:-$GITHUB_TOKEN}
git remote set-url origin https://x-access-token:$COMMITTER_TOKEN@github.com/$GITHUB_REPOSITORY.git
git config --global user.email "$USER_EMAIL"
git config --global user.name "$USER_NAME"

git remote add fork https://x-access-token:$COMMITTER_TOKEN@github.com/$HEAD_REPO.git

set -o xtrace

# make sure branches are up-to-date
git fetch origin $BASE_BRANCH
git fetch fork $HEAD_BRANCH

URL="https://api.github.com/repos/${BASE_REPO}/pulls/${PR_NUMBER}/files"
FILES=$(curl -s -X GET -G $URL | jq -r '.[] | .filename')
declare -i count=0
declare -i ZERO=0

for FILE in $FILES; do
if [ "${FILE##*.}" = "go" ]; then
count=$((count+1))
gofumpt -w "${FILE}"
fi
done

if [[ $count -eq $ZERO ]]; then
    COMMENT="You do not have any go files to format"
    PAYLOAD=$(echo '{}' | jq --arg body "$COMMENT" '.body = $body')
    COMMENTS_URL=$(cat /github/workflow/event.json | jq -r .pull_request.comments_url)
    if [ "COMMENTS_URL" != null ]; then
    curl -s -S -H "Authorization: token $GITHUB_TOKEN" --header "Content-Type: application/json" --data "$PAYLOAD" "$COMMENTS_URL" > /dev/null
    fi
    exit $SUCCESS
fi

# Post results back as comment.
if [[ `git status --porcelain` ]]; then
    git status
    git add .
    git commit -m "Formatting files"
    git push -f fork $HEAD_BRANCH
    COMMENT=":rocket: Your go files have been formatted successfully"
    PAYLOAD=$(echo '{}' | jq --arg body "$COMMENT" '.body = $body')
    COMMENTS_URL=$(cat /github/workflow/event.json | jq -r .pull_request.comments_url)
    if [ "COMMENTS_URL" != null ]; then
    curl -s -S -H "Authorization: token $GITHUB_TOKEN" --header "Content-Type: application/json" --data "$PAYLOAD" "$COMMENTS_URL" > /dev/null
    fi
else
    COMMENT=":heavy_check_mark: That is a perfectly formatted change."
    PAYLOAD=$(echo '{}' | jq --arg body "$COMMENT" '.body = $body')
    COMMENTS_URL=$(cat /github/workflow/event.json | jq -r .pull_request.comments_url)
    if [ "COMMENTS_URL" != null ]; then
    curl -s -S -H "Authorization: token $GITHUB_TOKEN" --header "Content-Type: application/json" --data "$PAYLOAD" "$COMMENTS_URL" > /dev/null
    fi
fi
exit $SUCCESS