2d53848e0ce9a82e014bc48701da7da3244f106f
An adversarial audit of the headless peer-to-peer scenario suite
(crates/lanspread-peer-cli/scripts/run_extended_scenarios.py, driven by
`just peer-cli-tests`) found assertions that passed even when the behavior
they claim to test was not happening, plus timing races and doc-vs-code
divergences. A full baseline run (S1-S47) passed beforehand, confirming these
were test-quality gaps, not peer regressions; the baseline output itself
exposed the worst offenders -- e.g. S14 chunk totals {128 MiB, 1 MiB} (a
two-chunk file whose "balanced within one chunk" check can never fail) and
S16/S18 serving the whole ~120 MiB alienswarm.eti from a single source, so
fanout and retry were never exercised.
Test-correctness fixes (a broken behavior could previously pass green):
- S18: the "no download-failed" check was dead -- it reused a LineWaiter
already advanced past download-finished, so it scanned an empty tail.
Replaced with assert_no_event_since over the whole window. Switched to a
4*CHUNK_SIZE sparse archive so both peers get chunks; the test now proves the
download SURVIVES a mid-download source kill (every byte delivered, survivor
served part, no download-failed, clean diff). Retry-onto-survivor is the
mechanism but is not asserted: the kill/serve race against `docker rm -f`
cannot be forced, so asserting an exact split would be flaky.
- S7: the only check was a diff against byte-identical ggoo fixtures, so it was
source-agnostic. Added assertions that the download committed exactly once,
every chunk came from the validated two-peer set, both peers served, and no
chunk was fetched twice.
- S14: enlarged to 4*CHUNK_SIZE so the balance check can fail under a 3+1
imbalance; asserts an exact 2+2 split summing to the file size.
- S16: inflated the .eti to 2*CHUNK_SIZE so it fans out across both
catalog-version peers (the stock 120 MiB fixture is a single chunk).
- S37: validate the throughput rate fields (positive, self-consistent
mbit/mib == 8.388608, mib_per_s == bytes/duration), not just the byte count.
- S35: assert the source actually advertises the unknown game before checking
it is filtered, so "absent" means "filtered" and not "never sent".
- S15: cross-check each peer's raw advertised eti_version via list-peers; the
list-games eti_game_version is synthesized from the catalog and can only ever
equal the asserted value.
- S2: poll for library convergence and verify the bidirectional exchange
(bravo sees alpha's 3 games, not just alpha seeing bravo's 4).
- S12/S28: require the gating unit test to appear as "<name> ... ok" so an
#[ignore]d (un-run) test no longer satisfies the check.
- S24/S25: assert the requested install=false final state.
- S34: assert exactly 21 coherent chunks (20 files + version.ini), 21 distinct
paths, no duplicates, instead of a >= 21 floor.
Flake fixes:
- S19: force-kill the sole source right after download-begin on a 4*CHUNK_SIZE
file and accept download-failed or download-peers-gone. The old graceful
shutdown on a single-chunk file could let the transfer finish first, turning
the expected failure into a download-finished. A chunk may complete before
the kill lands, but the full transfer cannot, so the failure is deterministic.
- S26: use a large sparse source so the first operation is reliably still
active when the duplicate request is issued (TOCTOU on active_operations);
also assert the active operation == "Downloading".
- S11: drop the "listener address must change" assertion -- it tested the OS
ephemeral-port allocator and could fail spuriously; keep the same-identity /
no-duplicate invariant.
Coverage and determinism:
- S27: add handshake::tests::inbound_hello_from_self_is_ignored for the
protocol-level self guard. The CLI scenario only exercises the CLI
string-compare guard, which short-circuits before any network call, so the
peer-crate guard had no test.
- find_fixture_game now iterates sorted(FIXTURES) so the ambiguous cnctw
(fixture-bravo/multi/solid) resolves deterministically to fixture-bravo.
Reviewed and deliberately left as-is (documented in the run log): S20, S21,
S30, S32/S39/S44 absence checks, S42 IP-order precondition, S45.
PEER_CLI_SCENARIOS.md rows S2, S11, S14, S16, S18, S19, S27 are updated to
match the harness, and a dated run-log entry records the audit, the fixes, the
accepted items, and the live-run evidence.
Test Plan:
- `just peer-cli-tests` (rebuilds the image, runs S1-S47 in Docker): baseline
passed; post-fix passed; a final run on the exact committed code passed
47/47. Evidence: S14 {268435456, 268435456} balanced 2+2; S16 .eti split
across B and C {134217728, 134217728}; S18 all 536870912 bytes delivered with
no download-failed; S19 deterministic download-failed; S37 ~874 MiB/s.
- `just test` (incl. inbound_hello_from_self_is_ignored), `just clippy`
(-D warnings, all-targets), and `just fmt` all pass.
Refs: PEER_CLI_SCENARIOS.md scenario matrix and 2026-06-21 run-log entry.
lanspread
Peer-to-peer game library sharing for LAN parties. Peers discover each other on the local network via mDNS, exchange library metadata over QUIC, and let users browse and download games from each other. Ships as a Tauri desktop app.
Build / install
Install Rust, Deno, and just first, then bootstrap the project:
just setup
That installs the Tauri CLI with cargo install tauri-cli and installs the
Deno/npm dependencies from crates/lanspread-tauri-deno-ts.
Run the desktop app in development mode:
just run
Build without bundling:
just build
Create production bundles:
just bundle
Important just commands
just setup- install the Tauri CLI and frontend dependencies.just run- run the Tauri app in dev mode.just build- build the app without bundling.just bundle- create production bundles.just fmt- format Rust, TOML, and the justfile.just clippy- lint the Rust workspace.just test- run workspace tests.just frontend-test- run frontend tests.just peer-cli-build- build the JSONL peer test harness.just peer-cli-image- build the peer harness Docker image.just peer-cli-run NAME- run one peer harness container.
Description
Languages
Rust
58.1%
TypeScript
12.5%
JavaScript
11.8%
Python
9%
CSS
6.8%
Other
1.7%