code: function fileChecks( filepath )
  		{
  			// check if file exists
  			if (!grunt.file.exists(filepath))
  			{
  				grunt.log.warn('Source file "' + filepath + '" not found');
  				return false;
  			}
  
  			if(options.checkFilesize)
  			{
  				// check for size
  				var stats = fs.lstatSync( filepath );
  
  				if(stats.size > UNCRITICAL_FILE_SIZE)
  				{
  					grunt.log.warn('uncritical datauri size (' + filesize(UNCRITICAL_FILE_SIZE) + ') exceeded: ' + filepath + ' (' + filesize(stats.size) + ')');
  				}
  			}
  
  			return true;
  		}
docs: Warn on and remove invalid source files (if nonull was set). ~~~~~~~~~~~~~~~~~~~~~