Place to put assets for dev/test in emberjs

I'm using mirage to mock some data and I'd like to mock an <img> with the appropriate file.

The problem is that I will have to place the image in /public/assets and the images placed there will be deployed later on as well.

Is there a way to avoid this? I couldn't find a recommendation in the ember cli website (https://ember-cli.com/user-guide/#asset-compilation)

I found one addon that could do this (ember-test-assets), but I'd like to avoid installing extra addons as much as possible.

Thanks!