Found by finally running the banner I shipped in 0.3 instead of trusting that
it compiled.
`blocked()` read `user_id` from rows the relay emits as `{id, name, slug}` —
the buddy-list shape, not the `user_id` shape the §8 routes use. It threw
`No value for user_id`. Tapping Block worked on the server and then showed the
user an error, which on a safety action is the worst outcome available: it
succeeded and the screen said otherwise.
The reason it survived is the reason it was dangerous. The block list is empty
until somebody blocks their first person, so the map never ran and every test
passed. The first block anybody performed broke it.
🔴 And it did not stop at a message. `adoptStrangers` read the block list with
`.getOrDefault(emptyList())`, so the throw became "nobody is blocked" — and the
next message from someone you had just blocked auto-added them back to your
contacts, defeating the exact property the code comment above it claims to
hold. That now fails closed: if the block list cannot be established, nothing
is adopted and the next poll tries again. A stranger appearing a few seconds
late is cosmetic; re-adding somebody who blocked their way out of a
conversation is not.
The new test uses a NON-EMPTY list, because that is the case that was missing —
an empty-list assertion looks like coverage and exercises no parsing. Confirmed
by reintroducing the bug: the populated case fails, the empty case still
passes.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>