pre-commit

#!/usr/bin/env bash
#
# A Git pre-commit hook that checks for syntax errors
# for: Ruby, JavaScript, Python, Bash, Go, (Cake)PHP, and HTML
# based on the extensions of staged files in Git.
# Can be 'installed globally' as of Git 1.7.1 using init.templatedir
#
# Copyright 2013, kvz (http://twitter.com/kvz)

set -o pipefail
set -o errexit
set -o nounset
# set -o xtrace
__DIR__="$(cd "$(dirname "${0}")"; echo $(pwd))"
__BASE__="$(basename "${0}")"
__FILE__="${__DIR__}/${__BASE__}"

if [ -x "${__DIR__}/pre-ochtra" ]; then
  echo "Running pre-ochtra"
  if ! ${__DIR__}/pre-ochtra; then
    echo "pre-ochtra failed"
    exit 1
  fi
fi

# Takes a command as arguments and paints both it's STDOUT & STDERR in
# colors specified in first and second arguments. Use 'purge' to skip printing
# at all
function paint() (
  set -o pipefail;

  green=$'s,.*,\x1B[32m&\x1B[m,'
  red=$'s,.*,\x1B[31m&\x1B[m,'
  gray=$'s,.*,\x1B[37m&\x1B[m,'
  purge="/.*/d"

  stdout="${!1}"
  stderr="${!2}"

  ("${@:3}" 2>&1>&3 |sed ${stderr} >&2) 3>&1 \
                    |sed ${stdout}
)

# Necessary check for initial commit
against="4b825dc642cb6eb9a060e54bf8d69288fbee4904"
git rev-parse --verify HEAD >/dev/null 2>&1 && against="HEAD"

# Only run when we're on a branch (to avoid rebase hell)
# http://git-blame.blogspot.nl/2013/06/checking-current-branch-programatically.html
# --short is not supported on older git versions so using awk here
if branch=$(git symbolic-ref -q HEAD |awk -F/ '{print $NF}'); then
  echo on branch $branch
else
  echo not on any branch
  exit 0
fi

# (A)dded (C)opied or (M)odified
git diff-index --cached --full-index --diff-filter=ACM $against |while read -r line; do
  mod="$(echo ${line} |cut -d' ' -f2)"
  sha="$(echo ${line} |cut -d' ' -f4)"
  sts="$(echo ${line} |cut -d' ' -f5)"
  pth="$(echo ${line} |cut -d' ' -f6-)"
  ext="${pth##*.}"

  she=""
  # only check shebang on normal and executable files
  if [ "${mod}" = "100644" ] || [ "${mod}" = "100664" ] || [ "${mod}" = "100455" ]; then
    she="$(head -n1 ${pth} |awk -F/ '/^#\!/ {print $NF}' |sed 's/^env //g')"
  fi
  out="purge"
  err="red"
  cmd=""
  tmp=""

  # Select linting tool based on extension or shebang
  if [ "${ext}" = "rb" ] || [ "${ext}" = "erb" ] || [ "${she}" = "ruby" ]; then
    cmd="ruby -c -"
  elif [ "${ext}" = "js" ] || [ "${she}" = "node" ]; then
    # jshint unfortunately uses STDOUT for errors, so paint all red
    cmd="jshint -"
    out="red"
  elif [ "${ext}" = "es6" ] || [ "${she}" = "node" ]; then
    # eslint need to be in localfolder, for example using npm install peasant
    # if use global installed eslint not works with .eslintrc
    # cmd="node_modules/.bin/eslint --stdin"
    # or use global without .eslintrc
    cmd="eslint --stdin --no-eslintrc"
    out="red"
  elif [ "${ext}" = "ts" ] ; then
    tmp="${TMPDIR:-/tmp}/${$}.${ext}"
    cmd="tslint ${tmp}"
  elif [ "${ext}" = "coffee" ] || [ "${she}" = "coffee" ]; then
    # coffeelint unfortunately uses STDOUT for errors, so paint all red
    cmd="coffeelint --quiet --stdin"
    out="red"
  elif [ "${ext}" = "py" ] || [ "${she}" = "python" ]; then
    tmp="${TMPDIR:-/tmp}/${$}.${ext}"
    cmd="pylint --errors-only ${tmp}"
    out="red"
  elif [ "${ext}" = "go" ]; then
    cmd="gofmt -e"
  elif [ "${she}" = "sh" ]; then
    cmd="sh -n"
  elif [ "${ext}" = "php" ] || [ "${ext}" = "ctp" ] || [ "${she}" = "php" ]; then
    cmd="php -n -l -ddisplay_errors=1 -derror_reporting=E_ALL -dlog_errors=0"
  elif [ "${ext}" = "pl" ] || [ "${she}" = "perl" ]; then
    cmd="perl -wc -"
  elif [ "${ext}" = "xml" ] || [ "${ext}" = "xsl" ] || [ "${ext}" = "xslt" ]; then
    cmd="xmllint --noout -"
  elif [ "${ext}" = "json" ]; then
    cmd="jsonlint"
  elif [ "${ext}" = "yaml" ] || [ "${ext}" = "yml" ]; then
    tmp="${TMPDIR:-/tmp}/${$}.${ext}"
    cmd="js-yaml ${tmp}"
  elif [ "${ext}" = "html" ] || [ "${ext}" = "htm" ] || [ "${ext}" = "shtml" ]; then
    cmd="htmlhint stdin"
    out="red"
  elif [ "${she}" = "bash" ]; then
    cmd="bash -n"
  fi

  if [ -n "${cmd}" ]; then
    tool="$(echo "${cmd}" |cut -d' ' -f1)"
    paint "gray" "red" echo "--> ${tool} syntax checking for ${pth}"
  else
    paint "gray" "red" echo "--> No syntax checking for ${pth}"
    continue
  fi

  # require linting tool
  if ! which "${tool}" >/dev/null 2>&1; then
    paint "red" "red" echo "Please install ${tool} for pre-commit syntax checking. "
    exit 1
  fi

  # execute on staged buffer
  [ -n "${tmp}" ] && git cat-file -p ${sha} > "${tmp}"

  if ! git cat-file -p ${sha} |paint ${out} ${err} ${cmd}; then
    paint "red" "red" echo "Please fix ${tool} syntax errors and type 'git add ${pth}'"
    [ -n "${tmp}" ] && rm -f "${tmp}"
    exit 1
  fi

  [ -n "${tmp}" ] && rm -f "${tmp}"

  paint "green" "red" echo "No ${tool} syntax errors detected in '${pth}'"
done