fix: add ignoreAtomics option to isModified() for better backwards compatibility with Mongoose 5

[vkarpov15]

Re: #14024

Summary

Some of the work we did to make isModified() more consistent with what paths Mongoose validates and sends to MongoDB caused some trouble for users, so this PR adds a ignoreAtomics option to isModified() that can help smooth out the issues. Basically, with this ignoreAtomics option, isModified() will return false if passed an array path where the top-level array has a non-$set atomic operator. So if post.comments has a $push and no $set, then post.isModified('comments.0.title', { ignoreAtomics: true }) will return false.

Examples

[heyfirst]

hey @vkarpov15, thanks for promptly raise the PR for providing backward-compatibility option! We tested in our use-case and it works! Looking forward for this to be in release,

Also, another way if you want to release this one as canary like v6.12.4.14024 it's also works as well, we will able to install and try with our codebase 🙂

Our test we used to test it

[vkarpov15]

@heyfirst we shipped 6.12.5 yesterday with the fix