Git Pre-Commit for Style Checkers

pre-commit

#!/bin/bash
#
# Checks staged files for linter exceptions
# Add to PROJECT_ROOT/.git/hooks/, and make executable (i.e. chmod +x .git/hooks/pre-commit)

LINTERS_STATUS=0

function linter {
  local name=${1}
  local pattern=${2}
  local args="${@:3}"

  local msg_prefix="git pre-commit ($name)"

  # Messages
  fail() { >&2 echo "$msg_prefix: FAILED - $1"; LINTERS_STATUS=$(($LINTERS_STATUS|1)); }
  info() { echo "$msg_prefix: $1"; }

  # Check if linter is installed
  which "$name" > /dev/null 2>&1 || fail "Please install \`$name\`."

  local files=$(git diff --cached --name-only --diff-filter=AMC | grep "$pattern" | tr '\n' ' ')
  if [ -n "$files" ]; then
    msg="Validating $files"; info "${msg//\ \:/\:}"

    local margin=$(printf "%-4s" " ")

    local linter_output
    linter_output=$($name ${!args} $files)

    local linter_status=$?

    echo
    echo "$linter_output" | sed "s/^/$margin/"
    echo

    if [ $linter_status -ne 0 ]; then
      fail "Please fix Ruby style issues commiting."
    fi
  else
    info "No files to check."
  fi
}

linter rubocop "\.rb$" -f -s -c "$(git rev-parse --show-toplevel)/.rubocop.yml"
linter coffeelint "\.coffee$"

exit $LINTERS_STATUS

I might refactor this to allow for coffeelint usage too.

EDIT: Done!