ESLint check your code as a pre-commit hook

pre-commit

#!/bin/bash
# based on: https://gist.github.com/linhmtran168/2286aeafe747e78f53bf
STAGED_FILES=$(git diff --cached --name-only --diff-filter=ACM | grep "\.jsx\{0,1\}$")

if [[ "$STAGED_FILES" = "" ]]; then
    exit 0
fi

# Escape code
esc=`echo -en "\033"`

# Set colors
cc_normal="${esc}[0m"
cc_red="${esc}[0;31m"
cc_red_b="${esc}[0;41m"
cc_green="${esc}[0;32m"
cc_yellow="${esc}[0;33m"
cc_blue="${esc}[0;34m"

echo -e "Validating Javascript (pre-commit hook) ...\n"

# Check for eslint
which eslint &> /dev/null
if [[ "$?" == 1 ]]; then
    echo "${cc_red_b}Error: please install ESlint${cc_normal}"
    exit 1
fi

PASS=true
OUTPUT=""

for FILE in $STAGED_FILES; do
    echo -en "[...] checking $FILE"
    OUT=`eslint --color "$FILE"`

    if [[ "$?" == 0 ]]; then
        # echo -e "\t${cc_green}[passed]${cc_normal}"
        echo -e "\r[ ${cc_green}✔${cc_normal} ]"
    else
        # echo -e "\t${cc_red}[failed]${cc_normal}"
        echo -e "\r[ ${cc_red}✘${cc_normal} ]"
        OUTPUT="$OUTPUT $OUT"
        PASS=false
    fi
done

if [[ -n "$OUTPUT" ]]; then
    echo "---------- report ----------"
    echo -e "$OUTPUT"
    echo "----------------------------"
fi

echo -en "\nJavascript validation complete: "

if ! $PASS; then
    echo -e "${cc_red}Commit stopped${cc_normal}"
    echo "Your commit contains files that should pass ESLint but do not."
    echo "Please fix the ESLint errors and try again.\n"
    exit 1
else
    echo -e "${cc_green}Commit allowed${cc_normal}\n"
fi

exit $?