fix(model): skip applying static hooks by default if static name conflicts with aggregate middleware

[dragontaek-lee]

Fix #14903

Summary

Make it so that if the custom static overwrites an existing aggregate middleware, don't apply middleware to it by default. This should be achieved by filtering custom static-named aggregates in applyStaticHooks.js.

Furthermore, aside from this PR, I believe we should extend this filtering not only to query and aggregation middleware but also to other Mongoose middlewares, including Document and Model middleware. Does that make sense? If so, I would like to create another PR for this work.

Examples

schema.statics.aggregate = function(pipeline) {
    let match = { $match: { deleted: { '$ne': false } } };

    if (pipeline.length && pipeline[0].$match) {
        pipeline[0].$match.deleted = { '$ne': false };
    } else {
        pipeline.unshift(match);
    }

    const query = Model.aggregate.apply(this, [pipeline]);
    return query;
};

Assume that the static method overwrites the built-in Mongoose aggregate function.

schema.pre('aggregate', function(next) {
    console.log(this);
    next();
});

schema.post('aggregate', function() {
    console.log(this);
});

In this situation, also assume that there are pre and post hooks for aggregate.

With this PR, when a custom static method overwrites an existing aggregate middleware as described above, the middleware is not applied by default. As a result, the this context type in pre/post hooks is correctly set to Aggregate, as intended.

[vkarpov15]

Thanks 👍

[vkarpov15]

And yes you can create a separate PR to apply this filtering to other middleware types.

[dragontaek-lee]

@vkarpov15
Thanks for the review and comments! 👍
As per your guidance, I’ve created a separate PR (#14908). Please feel free to check it at your convenience!