The test files had grown their own copies of the same helpers: prefix()
twelve times, established() seven, an UPDATE builder six, a seventeen
field PeerConfig literal in fifteen places, a timeout constant in twenty
one. Each is in crates/integration-tests/src once now: peer_config() and
TestServer::with_peer for a configured peer, Announcement for building
UPDATEs, established(), the waits (wait_until, wait_for, wait_for_routes,
wait_for_sessions), get_json, and TIMEOUT. A new field on PeerConfig is
one line to add, not fifteen.
TestPeer::recv has a deadline, so a test that gets nothing fails instead
of hanging; is_closed, which read one byte and took a KEEPALIVE for an
open connection, is closed_within and closed_unanswered.
Net 788 lines fewer; every test checks what it did.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>