Mongodb driver doesn't detect deep updates

[briankchan]

Describe the bug

Changes in nested objects are not detected when flushing with the mongodb driver. (The same test seems to work fine with the sqlite driver, though.)

Reproduction

https://github.com/briankchan/mikro-orm-bug-mongodb-deep

What driver are you using?

@mikro-orm/mongodb

MikroORM version

tested on 6.2.2 and 6.2.7-dev.0

Node.js version

v20.12.2

Operating system

No response

Validations

• Read the Contributing Guidelines.
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• The provided reproduction is a minimal reproducible example of the bug.

[B4nan]

Interesting, thanks for a failing repro, I remember several cases like this and this one might be the first valid case actually.

Workaround for now is to reassign the whole object value:

usr2.a = { b: 100 };