I have a Jest test file as follows:

import mongoose from 'mongoose';
import { MongoMemoryServer } from 'mongodb-memory-server';

describe('mySystem', () => {
    let inMemoryDb: InMemoryDb;
    let queryCount = 0;

    beforeAll(() => {
        mongoose.set('debug', (_collectionName, _method, _query, _doc) => {
            queryCount++;
        });
    });

    beforeEach(async () => {
        inMemoryDb = await useInMemoryDb();  // Uses MongoMemoryServer
        queryCount = 0;
    });

    afterEach(async () => {
        await inMemoryDb.cleanUp();  // Disposes of MongoMemoryServer
    });

    it('should do one thing', async () => {
        // Do something with the DB here
        expect(queryCount).toBe(2);
    });

    it('should do another thing', async () => {
        // Do something with the DB here
        expect(queryCount).toBe(3);
    });
});

This checks per use case how many queries are made. If the tests are running sequentially, this works fine. However, if the tests are running in parallel, the tests interfere with each other, even though they each have their own database. This results for instance that all queries from the two individual tests are counted towards a single queryCount.

1. Would it be possible to change this query counter such that it uses a unique query counter per test case?
2. If not, how can I prevent that tests run in parallel? I already have set maxConcurrency: 1 and maxWorkers: 1 in my Jest config, and use the runInBand flag when I run the tests, but still they're executed in parallel.