node.js - Node Js NPM sharp. cannot write .gif to file -

i making image resizer website (it resizes image based on the width of container in).

i can save , server jpeg's , png's cannot seem save .gif's file.

this code works jpg's , png's

    sharp(imgpath)       .resize(containwidth, null)       .withoutenlargement()       .tofile(modimgpath, function(err) {         if(err){console.log(err)}       });  

i can gif's display in browser (with code below) cannot save them file.

    sharp(imgpath)       .resize(modimgpath, null)       .withoutenlargment()       .tobuffer(function(err, outputbuffer) {         if (err) {console.log(err)}       } 

iv looked how save image buffers file nothing seems work.

currently gif output seems unsupported in sharp.

https://github.com/lovell/sharp/issues/162

https://github.com/lovell/sharp/issues/245

one solution, though haven't tried see if works, change output format. save first frame of gif.