toJSON or reverseTranslateAliases function to return alias keys

[abhisekp-bac]

Do you want to request a feature or report a bug?

feature

What is the current behavior?

findOneAndUpdate query toJSON doesn't return the aliased keys. Rather it returns the original keys.

If the current behavior is a bug, please provide the steps to reproduce.

What is the expected behavior?
toObject or toJSON should return the aliased keys instead of the raw keys. Or a custom function like reverseTranslateAliases can be implemented.
Related to #5184

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.
mongoose: 5.6.2
node: 12.0.0
npm: 6.9.0

[abhisekp-bac]

Adding the following to the mongoose schema options solves the issue. It removes all the raw keys and only aliases are left.

{
    toJSON: {
      virtuals: true,
      transform: (doc: any, ret: any, opts: any) => {
        Object.keys(doc.schema.obj)
          .filter(k => doc.schema.obj[k].alias)
          .forEach(ak => delete ret[ak]);
      }
    }
}

Maybe a plugin can help?

[vkarpov15]

This is by design. The primary purpose of aliasing keys is to reduce storage in the database and network overhead between Node.js and MongoDB by shortening the keys when they're stored in the database, and converting the aliased keys back to long-form keys in Node.js.

[klemensz]

If it's by design, then why doesn't it work as designed?

[vkarpov15]

@klemensz if it doesn't work as designed, please open up a new issue and follow the issue template.