google apps script - .getFilesByType() does not seem to be working -

i have folder may or may not contain forms , connected response spreadsheets. however, code below returns false when these files present.

  //checks number of google forms in subdomain folder   var files = myfolder.getfilesbytype('google_sheets');   logger.log(files.hasnext()); 

this code returns true:

  var files = myfolder.getfiles();   logger.log(files.hasnext()); 

i'm imagining i'm somehow getting mimetype wrong, far can see in google's documentation correct. i'd rather check these file types instead of checking files.

any thoughts?

mimetype.google_sheets

try instead of 'google_sheets'. i'm not able test @ moment, format google documentation asking for. take notice there not quotes around it.