Git hook to validate modified code against PSR-2 code standard

composer.json

{
  "require-dev": {
    "squizlabs/php_codesniffer": "^3.2",
    "exussum12/coverage-checker": "^0.10.0"
  }
}

pre-commit

#!/usr/bin/env bash

# Based on code from http://tech.zumba.com/2014/04/14/control-code-quality/

PROJECT=$(php -r "echo dirname(dirname(dirname(realpath('$0'))));")
STAGED_FILES_CMD=$(git diff --cached --name-only --diff-filter=ACMR HEAD | grep \\.php)
DIFF_SUFFIX="_diff"
PHPCS_SUFFIX="_phpcs.json"
declare -i ERROR_COUNTER=0

if [ "$#" -eq 1 ]
then
    oIFS=$IFS
    IFS='
    '
    SFILES="$1"
    IFS=$oIFS
fi
SFILES=${SFILES:-$STAGED_FILES_CMD}

echo "Checking for errors PHP Lint..."
for FILE in $SFILES
do
    php -l -d display_errors=0 $PROJECT/$FILE
    if [ $? != 0 ]
    then
        echo "Fix your errors before commit!"
        exit 1
    fi
    FILES="$FILES $PROJECT/$FILE"
done
 
if [ "$FILES" != "" ]
then
    echo "Sniffing your code..."

    TMP_DIR=/tmp/$(uuidgen)
    mkdir -p $TMP_DIR
    for FILE in $SFILES
    do
        mkdir -p $TMP_DIR/$(dirname $FILE)
        git show :$FILE > $TMP_DIR/$FILE
        git diff master $FILE > $TMP_DIR/$FILE$DIFF_SUFFIX
        ./vendor/bin/phpcs --standard=psr2 --report=json $TMP_DIR/$FILE > $TMP_DIR/$FILE$PHPCS_SUFFIX
        ./vendor/bin/diffFilter --phpcs $TMP_DIR/$FILE$DIFF_SUFFIX $TMP_DIR/$FILE$PHPCS_SUFFIX
        PHPCS_ERROR=$?
        ERROR_COUNTER=$ERROR_COUNTER+$PHPCS_ERROR
    done
    rm -rf $TMP_DIR
    if [ $ERROR_COUNTER != 0 ]
    then
        echo "You code stinks. :P Fix your style before commit."
        exit 1
    fi
fi

exit $?