resolve_subscription_url now hands its request to resolve_with, which
takes the request as a closure, so the export's paths are tested without
the network:
- a link carrying its channel id is answered without a request: the
export itself, on three links including music.youtube.com;
- an answer that is not a channel id is refused, and YouTube is asked
about the path the link names;
- the entry log line carries the link's length and not the link, read
back through a capturing logger.
Measured on the audited channel.rs: the audit's FA15, FA16 and FA17 each
passed all 30 tests. With these tests, FA17 and the successors of FA15
and FA16 (their lines changed here) each fail one test; FA16 as written
no longer compiles.
Cobb
0653053484