Git pre-commit hook to check for debugging codes and Standard JS violations in a Javascript project

pre-commit

#!/bin/bash

FILES_PATTERN='\.(css|less|scss|sass|html|ejs|js|jsx)(\..+)?$'
FORBIDDEN=( ">>>>>>" "<<<<<<" "======" "console.log" "debugger" )

# the exit code from `grep -E $FILES_PATTERN` gets swallowed unless the pipefail option is set
set -o pipefail

FORBIDDEN_FOUND=false

# grep for forbidden patterns
for i in "${FORBIDDEN[@]}"
do
  git diff --cached --diff-filter=ACMR --name-only | grep -E "$FILES_PATTERN" | \
    xargs grep --color --with-filename -n "$i" \
    && echo 'COMMIT FAILED: Found' "$i" 'references. Commit with \033[0;32m--no-verify \033[0mto bypass this check.' \
    && FORBIDDEN_FOUND=true
done

$FORBIDDEN_FOUND && exit 1

# just ignore pipefail exit code
set +o pipefail

# check for Standard JS violations
standard $(git diff --name-only --cached --relative | grep -E '\.(js$|jsx)(\..+)?$')

exit "$?"

Use xargs -r on Linux.