[hsheth2]

Fixes #1172

Problem

If a client's socket closes in the same event-loop turn as await server.stop() followed by await db.close(), the server later throws an unhandled TypeError: Cannot read properties of undefined (reading '_IsTransactionBlock'). The socket's close listener defers handleClose() with setImmediate. stop() detaches the same handler and resolves, and db.close() finishes. Then the deferred handleClose() calls detach() again. detach() calls clearTransactionIfNeeded(), and so db.isInTransaction(), before it checks whether the handler is still attached. handleClose() doesn't await detach(), so the error is an unhandled rejection.

The README example and the pglite-server CLI exit the process right after db.close(), so they never run the deferred callback. Test suites that start and stop a server per file do run it.

Change

detach() returns before it touches the query queue or the database when the handler has no socket. The existing check after the await stays, because a second detach can finish while the first one waits for a ROLLBACK.

Tests

• Added tests/stop-then-close.test.ts. It starts the stop() and db.close() shutdown from the server-side socket's close event, which makes the race deterministic, and asserts that no unhandled rejection follows. It fails on main with the _IsTransactionBlock TypeError and passes with this change, 5 out of 5 repeated runs.
• tsc, eslint ./src ./tests --max-warnings 0 and prettier --check ./src ./tests are clean.
• I couldn't build the PGlite WASM locally, so I ran the socket package's tests against the published @electric-sql/pglite@0.5.13. In that setup, 7 tests in index.test.ts, query-with-node-pg.test.ts, query-with-postgres-js.test.ts and extended-query-error.test.ts fail on main both with and without this change. They need workspace builds I didn't have. All the other tests pass, including connection-cleanup.test.ts.

This change was made with AI assistance. The tests above were run locally before opening this PR.

[tdrz]

Thanks!