format_code.sh

# This script formats staged C++ and build files. Files that are already committed
# will not be checked. So please run this script before you commit your changes.
# In case you did commit them, you can use "git reset --soft HEAD~1" to undo the
# commit and commit again after formatting it.

set -e
set -o pipefail

if [ $(git diff --name-only | wc -l) -ne 0 ]; then
  echo "Please stage or stash unstaged changes first."
  exit 1
fi

ls_staged_files () {
  # Don't throw errors if egrep find no match.
  echo $(git diff --name-only --cached --diff-filter=d | egrep $1 || true)
}

# Formatting cpp files using clang-format.
cpp_files=$(ls_staged_files "\.h|\.cc|\.cpp")
if [ "$cpp_files" ]; then
  clang-format -i --verbose -style=google $cpp_files
fi

# Formatting build files using buildifier.
build_files=$(ls_staged_files "WORKSPACE|*BUILD|*BUILD.bazel|*\.bzl")
if [ "$build_files" ]; then
  buildifier -v $build_files
fi

# Formatting Java files.
CACHE_DIR="/tmp/google-java-format-cache"
mkdir -p $CACHE_DIR
cd $CACHE_DIR
if [ ! -f google-java-format-1.7-all-deps.jar ]
then
    curl -LJO "https://github.com/google/google-java-format/releases/download/google-java-format-1.7/google-java-format-1.7-all-deps.jar"
    chmod 755 google-java-format-1.7-all-deps.jar
fi
cd -

java_files=$(ls_staged_files "\.java")
if [ "$java_files" ]; then
  java -jar $CACHE_DIR/google-java-format-1.7-all-deps.jar --replace  $java_files
fi