Q: Does the undertaking of a Covid-19 test whilst fasting affect the validity of the fast?
A: Our understanding of the Covid-19 test is that swabs of cottonwool at the end of what looks like a long cotton bud are inserted into the nasal cavity and the back of the mouth/upper throat, with a part of the apparatus outside the nose and mouth. It is then removed without anything apparently going down the throat.
In this case, undertaking such a test whilst fasting will NOT affect the validity of the fast.
And Allah Ta'ala Knows Best
Darul Ihsan Fatwa Department