[LiamCarPer]

Closes #825, part of #727.

Motivation

The redis, postgres and mongodb adapter test suites were almost the same code copied three times: broadcast.rs was 96-97% identical, rooms.rs 99%, sockets.rs 86% and local.rs 100%. A change or a fix had to be made three times, and the redis regression test from #782 is a good example of a test that only landed in one adapter.

Solution

Added crates/adapter-test-suite (publish = false, dev-dependency of the three adapters):

• Fixture trait implemented by each adapter: spawn_servers, spawn_buggy_servers and add_ns (the last one awaits the adapter init future, whose type/error differ per adapter).
• The shared test bodies for broadcast, rooms, sockets and local, generic over F: Fixture.
• The timeout_rcv!, timeout_rcv_err! and assert_now! macros.

Each adapter keeps its fixture.rs (the stub driver) plus a small Fixture impl, and its test files are now thin wrappers like:

#[tokio::test]
async fn broadcast() {
    adapter_test_suite::broadcast::broadcast::<fixture::Fixture>().await;
}

Adapter specific tests stay where they are: postgres attachments.rs, postgres/mongodb close.rs, and the redis remote_socket_emit_with_ack_targeted_terminates test from #782.

This also drops a couple of debug leftovers that had been copied into the postgres/mongodb tests (dbg! in rooms, a tracing_subscriber init in broadcast) since the shared bodies use the redis versions.

Tests

Same test count per adapter before and after (redis 29, postgres 29, mongodb 21). cargo test --all-features --workspace, cargo clippy --all-features --workspace --examples --tests -- -D warnings and cargo fmt --check are green.

Net: ~670 lines removed.

[codspeed]

Merging this PR will not alter performance

1 warning

⚠️ 4 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

✅ 87 untouched benchmarks

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_{Comparing LiamCarPer:refactor/share-adapter-test-suite (3ab1692) with main (d03ed5c)}