sgg.sh

#!/bin/bash
# Example usage:
# ./sgg.sh http://islands-components.incrop.lego-dev.dev.yandex-team.ru/ popup

GATHER_URL=${1:-https://lego-staging.dev.yandex-team.ru/islands-components/dev/}
BLOCK=$2

DIR_MAIN=gemini/screens
DIR_DIFF=gemini-report/diff
IMG_DIFF=./current-diff.png
HYSTERESIS=0.0005           #TODO parse from .gemini.yml

mkdir -p ${DIR_DIFF}
rm -rf ${DIR_DIFF}/*

if [ -n "$BLOCK" ]; then
  mv ${DIR_MAIN}/${BLOCK} ${DIR_DIFF}
  ./node_modules/.bin/gemini gather --root-url=${GATHER_URL} gemini/${BLOCK}.gemini.js
else
  mv ${DIR_MAIN}/* ${DIR_DIFF}
  ./node_modules/.bin/gemini gather --root-url=${GATHER_URL}
fi

pushd ${DIR_MAIN}
FILES="$(find . -type f | grep ^./${BLOCK})"
popd

echo "$FILES" | while read f; do
  CMP_RESULT=$(gm compare -metric MSE  -maximum-error ${HYSTERESIS}  -file ${IMG_DIFF} "./$DIR_MAIN/$f" "./$DIR_DIFF/$f" 2>&1)
  if [ 0 == "$?" ]; then
    echo "     same: $f"
    mv "./$DIR_DIFF/$f" "./$DIR_MAIN/$f"
  else
    echo "different: $f"
    optipng "./$DIR_MAIN/$f" -silent
    mv -f ${IMG_DIFF} "./$DIR_DIFF/$f"
  fi
done

rm -rf ${IMG_DIFF}
find ${DIR_DIFF} -type d -empty -delete

В чём назначение этого скрипта?