A conn knows and stores if it was already used to make a request (iirc conn.state). So your two approaches are.
# conn was used before
conn =
conn
# assign current user to the used conn
|> Pow.Plug.assign_current_user(user, [])
# get/2 detects the conn as already being used and recycles it,
# which doesn't retain the assign you added
|> get(~p"/api/events/#{id}")
and
# conn was used before
conn =
build_conn()
# assign current user to the used conn
|> Pow.Plug.assign_current_user(user, [])
# get/2 detects the conn as not used yet, so no recycling is happening
# the assign stays
|> get(~p"/api/events/#{id}")
You could do conn |> recycle() |> Pow.Plug.assign_current_user(user, []) to work around the automatic recycling happing at an inconvencient time.
You could also consider not writing to conn.assigns, but to put the authentication details in the session. That way authentication will persist across recycles just like it does persist across many requests outside of testing.
