Chaining .find with $and condition overwrites prior conditions

[Rouby]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

6.7.0

Node.js version

18.x

MongoDB server version

4.x

Typescript version (if applicable)

No response

Description

Chaining multiple .find (or other methods that manipulate the conditions) with $and (or other array-based conditions) results in the latest method silently overwriting any previous conditions.

This issue is relevant specifically for the use-case with the package @casl/mongoose that has utility methods to add constraints to queries based on the ability of an user.

E.g.

    MyModel.accessibleBy(userAbility)
      .countDocuments(additionalConditions)
      .exec(),

The query-conditions generated by accessibleBy might be silently overwritten if they happen to utilize $and and the additionalConditions do so too.

Steps to Reproduce

MyModel.find({ $and: [{ type: { $in: ['X'] } }] })
        .find({ $and: [{ type: { $in: ['Y'] } }] })
        .countDocuments({ $and: [{ type: { $in: ['Z'] } }] })
        .getQuery(),

//? {"$and":[{"type":{"$in":["Z"]}}]}

Expected Behavior

Since other conditions are merged, I would expect array-conditions to also be merged.

MyModel.find({ $and: [{ type: { $in: ['X'] } }] })
        .find({ $and: [{ type: { $in: ['Y'] } }] })
        .countDocuments({ $and: [{ type: { $in: ['Z'] } }] })
        .getQuery(),

//? {"$and":[{"type":{"$in":["X"]}},{"type":{"$in":["Y"]}},{"type":{"$in":["Z"]}}]}