Pre remove hook - Mongoose

Question

Right now I have an item, and when I remove the item, it triggers the pre 'remove' hook to remove an option group.

item.remove();

itemSchema.pre('remove', async () => {
  await OptionGroup.find({ _id: { $in: this.optionGroups } })
    .remove()
    .exec();
});

The option group has a pre 'remove' hook to remove the options that is referenced by the option group.

optionGroupSchema.pre('remove', async () => {
  await Item.updateMany(
    { optionGroups: this._id },
    { $pull: { optionGroups: this._id } }
  ).exec();
  await Option.find({ _id: { $in: this.options } })
    .remove()
    .exec();
});

I expected a waterfall effect but instead, only the option group is removed. There are other caveats that I do not understand, such as using find to remove is fine, but I cannot directly use remove or deleteMany like this:

itemSchema.pre('remove', async () => {
  await OptionGroup.remove({ _id: { $in: this.optionGroups } })
    .exec();
});

I know from the docs that I can only trigger a pre 'remove' hook when removing document, but in the hook, why I cannot use remove to trigger other pre 'remove' hooks?

So I think for me to understand, I need to know:

1. How to trigger a waterfall effect where one remove (document) will trigger the remove of others?
2. When to use deleteMany vs remove?
3. Does deleteOne or deleteMany trigger the pre 'remove' hook?

Answer 1

Does deleteOne or deleteMany trigger the pre 'remove' hook?

It won't trigger remove hook, you need to use this syntax instead.

schema.post(/Many$/, function(res) {
  console.log('this fired after you ran `updateMany()` or `deleteMany()`);
});