#!/bin/bash

# Copyright 2024 The gVisor Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Check if any changes are in specified paths. The script exits with 0 if no
# changes were detected.

set -xeo pipefail

exec 1>&2

if [[ -z "${BUILDKITE_BRANCH:-}" ]]; then
  echo "BUILDKITE_BRANCH is not set"
  exit 1
fi

baseid=''
if [[ "$BUILDKITE_BRANCH" == master ]]; then
  # If we are already on the master branch (this is a continuous test),
  # we should diff against the previous commit.
  baseid='HEAD~1'
else
  git fetch origin master
  baseid="$(git merge-base origin/master "origin/${BUILDKITE_BRANCH}")"
fi

git diff --stat "${baseid}" --exit-code "$@"
