Git Pre-Commit Hook For Rubocop

colours.sh

# Linux Echo colours
red='\033[0;31m'
nc='\033[0m'
black='\033[0;30m'
dark_grey='\033[1;30m'
light_red='\033[1;31m'
green='\033[0;32m'
lgreen='\033[1;32m'
orange='\033[0;33m'
yellow='\033[1;33m'
blue='\033[0;34m'
lblue='\033[1;34m'
purple='\033[0;35m'
lPurple='\033[1;35m'
cyan='\033[0;36m'
lcyan='\033[1;36m'
lGray='\033[0;37m'
white='\033[1;37m'
bold='\033[1m'

pre-commit.sh

#!/bin/bash
source ~/colours.sh

#########################################################################################
#                                   HOW to use it
# 1. Copy pre-commit.sh to your projects .git/hooks
# 2. make sure it is executable, else make it by `sudo chmod +x .git/hooks/pre-commit.sh`
# 3. Copy colours.sh to $HOME directory
# 4. Reload the environment
##########################################################################################

# Array containing all checks/tasks we want to run in hook
hooks=(
  rubocop_hook
)

# Function corresponding to check/task in hooks array
function rubocop_hook() {
  local status length

  # Get all the staged files except deleted files
  files=$(git diff --name-only --cached --diff-filter=d)

  # Get word-length of files
  length=${#files}

  # Run rubocop hook only when length is "not equal" to 0
  if [[ length -ne 0 ]]; then
    echo $files | xargs bundle exec rubocop --extra-details --parallel --force-exclusion
  fi
}

function thanks_hook() {
  echo "Thank YOU"
}

# Run hooks only when SKIP environment variable is not set
if [[ -z "$SKIP" ]]
then
  printf "\n${cyan}${bold}Running pre-commit hooks${nc}\n"

  for hook in "${hooks[@]}"; do
    ${hook}

    # Get exit status of command executed
    status=$?

    # Status is 0 when command exit status when successfully executed
    if [[ $status -eq 0 ]]
    then
      printf "\n${cyan}Check ${bold}$hook${nc} ................................ ${nc}${green}${bold}Passed ✓${nc}\n"
    else
      printf "\n${cyan}Check ${bold}$hook${nc} ................................ ${nc}${red}${bold}Failed ✗${nc}\n"
    fi
  done
else
  printf "\n${red}${bold}⚠  Skipping pre-commit hooks${nc}\n"
fi
printf "\n\n"