Swiftlint only git diff files

#bin/bash 

set -e
set -o pipefail

# Run SwiftLint
START_DATE=$(date +"%s")

SWIFT_LINT=/usr/local/bin/swiftlint
SWIFT_LINT_YAML=.swiftlint.yml

EXCLUDED=($(sed -nE '/excluded:/,/(^$|:$)/p' ${SWIFT_LINT_YAML} | grep -v ':' | grep -v -e '^[[:space:]]*$' | sed -e 's/ - //g'))

contains () { 
    local seeking=$1 
    local in=1 
    for element in "${EXCLUDED[@]}"; do 
        if [ "$seeking" != "${seeking%$element*}" ]; then 
            in=0 
            break 
        fi 
    done 
    return $in 
}

# Run SwiftLint for given filename
run_swiftlint() {
    local filename="${1}"
    if [[ "${filename##*.}" == "swift" ]] && [[ $(contains $filename) == 1 ]]; then
        ${SWIFT_LINT} autocorrect --path "${filename}" --quiet
        ${SWIFT_LINT} lint --strict --path "${filename}" --quiet | sed 's/warning:/error:/g'
    fi
}

if [[ -e "${SWIFT_LINT}" ]]; then
    echo "SwiftLint version: $(${SWIFT_LINT} version)"
    # Run for both staged and unstaged files
    git diff --diff-filter=d --name-only | while read filename; do run_swiftlint "${filename}"; done
    git diff --diff-filter=d --cached --name-only | while read filename; do run_swiftlint "${filename}"; done
else
    echo "${SWIFT_LINT} is not installed."
    exit 0
fi

END_DATE=$(date +"%s")

DIFF=$(($END_DATE - $START_DATE))
echo "SwiftLint took $(($DIFF / 60)) minutes and $(($DIFF % 60)) seconds to complete."