The FakeXMLHttpRequest class is missing the overrideMimeType method, which is part of the XMLHttpRequest specification: https://www.w3.org/TR/XMLHttpRequest/#the-overridemimetype()-method. Applications or libraries relying on this method will get an "undefined is not a function" exception when using FakeXMLHttpRequest.
This PR adds the missing method and mimics its original behaviour.
The FakeXMLHttpRequest class is missing the
overrideMimeType
method, which is part of the XMLHttpRequest specification: https://www.w3.org/TR/XMLHttpRequest/#the-overridemimetype()-method. Applications or libraries relying on this method will get an "undefined is not a function" exception when using FakeXMLHttpRequest.This PR adds the missing method and mimics its original behaviour.