Adapter not closed on server closed

[jmnsf]

Unsure if this is an issue in the adapter itself or upstream, but when calling io.close(), the adapter's .close() function is never called, so the connection with MongoDB stays up. I suppose this isn't too serious when closing down a server since everything's torn down anyway, but can be annoying in CI.

Problem:

afterAll((done) => {
  io.close(done);
});

One would expect this to shut down cleanly, but after the suite's done:

Test Suites: 1 passed, 1 total
Tests:       5 passed, 5 total
Snapshots:   0 total
Time:        5.166 s, estimated 6 s
Ran all test suites matching /src\/__tests__\/io.test.js/i.
/.../node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js:153
        throw new Error('Collection method ' + i + ' is synchronous');
        ^

Error: Collection method watch is synchronous
    at NativeCollection.<computed> [as watch] (/.../node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js:153:15)
    at initChangeStream (/.../node_modules/@socket.io/mongo-adapter/dist/index.js:80:40)
    at Timeout._onTimeout (/.../node_modules/@socket.io/mongo-adapter/dist/index.js:99:17)
    at listOnTimeout (node:internal/timers:557:17)
    at processTimers (node:internal/timers:500:7)
error Command failed with exit code 1.

Which isn't great. A workaround is going into the default namespace and tearing down the adapter manually:

afterAll((done) => {
  io.close((err) => {
    io.of('/').adapter.close();
    done(err);
  });
});

Would be nice if this weren't necessary (or at least documented somewhere).

[darrachequesne]

@jmnsf that's a good point 👍 we will include this in the next release.

[fhp]

If you use multiple namespaces, use this to close them all:

const namespaces = io._nsps.keys();
for (const namespace of namespaces) {
    void io.of(namespace).adapter.close();
}

For Google visibility: in my case, this lead to the following error while running tests with Jest:

MongoNotConnectedError: Client must be connected before running operations

[darrachequesne]

For future readers:

This should be fixed by socketio/socket.io@bf64870, included in socket.io@4.7.5.