Memory leak

[Art3miX]

I'm using Jimp for a very simple thing, I read the uploaded file, if the size is over 300x300 pixels I resize it to 300x300 with scaleToFit and write the changed image to my server with writeAsync.

The memory spikes are crazy, and the big issue is that its not freeing the memory, it keeps high, I'm currently testing my app, but in real life my app would restart on daily basis when memory hit limit.

Expected Behavior

Memory drop down to normal levels.

Current Behavior

my normal memory of my program is around 75MB, after uploadig 1 image size of 5MB, memory spikes to 175MB and go down to 100MB, if i upload 5 different images with total of 13MB, the memory spikes to over 450MB and go back to 300MB, and stays like that.

Steps to Reproduce

Here is my code that I use.

Jimp.read(file.data).then((image) => {
        if (image.bitmap.width > 300 || image.bitmap.height > 300) {
          image.scaleToFit(300, 300);
        }

        return image.writeAsync(tempLocation).then(() => {
          image = undefined;
          delete image;
          return res.json({status: '200', data: {imageUrl: `${config.APP.HOST}/uploads/${fileName}`}});
        }).catch((err) => {return res.json({err});});
      }).catch((err) => {return res.json({err});});

I read the image, check if the size is over 300, if it is we scaleToFit to 300x300, write the image on our server for later use, and send back a successful response.

My upload functionality is only this, nothing is done except manipulating the image and saving to our server.

I also tried to remove the writeAsync functionality, and the spike still continue the same, so this must be an issue with scaleToFit to read.

I also tried to use delete image or set it to undefined, but it doesn't help.

I understood from other issues here that forcing the GC after I'm done will do the trick, but there must be an issue if it is not happening automatically.

[EDIT]
I tried to force GC:

        return image.writeAsync(tempLocation).then(() => {
          image = undefined;
          Jimp = undefined;
          delete Jimp;
          delete image;

          try {
            if (global.gc) {global.gc();}
          } catch (e) {
            console.log('Error: the --expose-gc argument was missing: `node --expose-gc index.js`');
          }

I tried multiple stuff but it didn't help, the memory still stay over 300MB, even after one hour, so it doesn't help.