check

#!/bin/sh
#
# To enable this hook, link or rename this file to "pre-commit".
# If you save it in your ~bin/ directory as "check" and link it as "pre-commit,"
# you can easily run it manually from a dirty wc in addition to running as hook

STATUS=0

SELF=`basename $0`
CACHED=""
if [ $SELF != "check" ]; then
  CACHED="--cached"
fi

if git rev-parse --verify HEAD >/dev/null 2>&1
then
	AGAINST=HEAD
else
	# Initial commit: diff against an empty tree object
	AGAINST=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi

JSHINTRC="$HOME/.jshintrc"

# Redirect output to stderr.
exec 1>&2

# List all javascript and json files to be committed
FILES=`git diff-index --diff-filter=AM --name-only $CACHED $AGAINST -- | egrep \.js`

for FILE in $FILES; do
  # Check for stray console statements
  # awk script rewrites the output from: <line no.>:<offending line>
  # to: <filename>:<line no.> stray console
  E_CONSOLE=`egrep -n 'console\.(log|error|debug|info|warn)' $FILE | awk -v fn=$FILE 'BEGIN{FS=":";}{ print fn":"$1" stray console";}'`

  if [ "$E_CONSOLE" ]
  then
    STATUS+=1
    echo "$E_CONSOLE"
  fi

  # jshint; also checks for debugger statements
  E_LINT=`jshint --config $JSHINTRC --extra-ext .js,.json $FILE`
  if [ $? -ne 0 ] ; then
    # sed script strips the penultimate blank line and final summary line
    echo "$E_LINT" | sed -e '/^$/ d' -e '$ d'
    STATUS+=10
  fi
done


# If there are whitespace errors, print the offending file names and fail.
# grep filters lines begging with "+" -- i.e., the text of the offending line
WS=`git diff-index --diff-filter=AM --exit-code --check $CACHED $AGAINST -- | egrep -v '^\+'`
if [ "$WS" ]; then
  echo "$WS"
  STATUS+=100
fi

exit $STATUS

Sample output:

public/js/boot.js:3 stray console
public/js/boot.js:4 stray console
public/js/boot.js: line 2, col 1, 'bar' is not defined.
public/js/boot.js: line 2, col 7, 'foo' is not defined.
public/js/router.js:6 stray console
public/js/router.js: line 6, col 20, Missing semicolon.
public/js/boot.js:3: trailing whitespace.
public/js/boot.js:4: trailing whitespace.