Run test
everything ok
Run again
everything ok
Run again
error
Run again
everything ok

*wtaf is happening?*
I googled for the cause of a "double callback" error and found out that supertest was throwing it when I was attaching a file to the API request. found no conclusive way to solve it, just that "supertest does it from time to time".

Trying to investigate further, I made a function to repeat the API request 5 times in a row. Everything passed. The run it again. Two failed. Again and everything passed.

this is bullshit

fml