7.0.0-RC2 BUG - mongo beforeUpdate changes not persisted

[codeconsole]

3 Solutions

1. Wrap FieldEntityAcess with ModificationTrackingEntityAccess. - Hibernate currently does something similar

#15136
This will not solve properties being marked dirty inside beforeUpdate() but will solve all calls entity access set calls inside event listeners. This will fix @AutoTimestamp.

2. Cache the Document on load and then override dirty calls. This is hibernates main mechanism. This will 2x memory usage of an entity. I have this PR ~90% complete with the exception of the original cache set call.

Hibernate does this + 1. Although doing both is probably redundant overkill and unnecessary.

3. Take a snapshot of the entity just prior to beforeUpdate() and event listeners being called, then mark any changes dirty. This is least invasive and does not have memory requirements of 2.

#15143

package mongo.test

import grails.gorm.annotation.AutoTimestamp

class User {

    String name

    Date dateCreated
    Date lastUpdated

    String random

    @AutoTimestamp(AutoTimestamp.EventType.CREATED) Date created
    @AutoTimestamp Date modified

    static constraints = {
        created nullable: true, display: false
        modified nullable: true, display: false
        random nullable: true, display: false
    }

    def beforeInsert() {
        random = "Not Updated"
    }

    def beforeUpdate() {
        random = UUID.randomUUID().toString()[0..4])
        assert isDirty('random') // throws exception in mongo, but NOT hibernate
    }
}

#15141

Hibernate Works Because:

isDirty('random') -> GormEntity.isDirty(String fieldName) -> HibernateGormInstanceApi.isDirty(D instance, String fieldName)

    boolean isDirty(String fieldName) {
        currentGormInstanceApi().isDirty(this, fieldName)
    }

HibernateGormInstanceApi compares against Hibernate's internal snapshot.

Mongo Does Not Work Because:

isDirty('random') -> GormEntity.isDirty(String fieldName) -> GormInstanceApi.isDirty(D instance, String fieldName)

GormInstanceApi does not compare against anything and only checks which properties have been specifically marked dirty.

[codeconsole]

#15143