lib/index.js
function getOutputFilePath(input, outputDir, suffix) {
  var inputArr = input.split(path.sep);
  var originFileName = inputArr[inputArr.length - 1];
  var newFileName = originFileName.replace(/\.png$/, suffix + '.png');
  var outputFilePath = path.join(outputDir, newFileName);
  return outputFilePath;
}
function getOutputFilePath(input, outputDir, suffix) {
  var inputArr = input.split(path.sep);
  var originFileName = inputArr[inputArr.length - 1];
  var newFileName = originFileName.replace(/\.png$/, suffix + '.png');
  var outputFilePath = path.join(outputDir, newFileName);
  return outputFilePath;
}
function getOutputFilePath ( input , outputDir , suffix ) { var inputArr = input . split ( path . sep ) ; var originFileName = inputArr [ inputArr . length - 1 ] ; var newFileName = originFileName . replace ( / \.png$ / , suffix + '.png' ) ; var outputFilePath = path . join ( outputDir , newFileName ) ; return outputFilePath ; }
get temp output file path with our suffix
@param  {string} output
@return {string} outputDir
@return {string} suffix
@return {string} outputFilePath
@private
get temp output file path with our suffix