Many JS tests do something like the following:

const conn = MongoRunner.runMongod();
const db = conn.getDB("test");
const coll = db.getCollection(jsTestName());
assert.commandWorked(coll.stats())
coll.drop();

But since the IDE can't put together what type the initial conn variable is (becomes an "any" or even a "never" due to overrides), the rest can't get any helpful hints from .d.ts type files.

This might be a limitation of not having well-scoped variables (global, not using exports, etc), but some mitigation may exist to help provide devs with better UX without a large amount of churn (redesign!) to the system.

Ideally, solutions should extend beyond just these two variables, or to at least demonstrate an example for others to follow suit.