Add new change types for properties on subclassing

[franktominc]

No description provided.

[franktominc]

Moved from #825

[franktominc]

There are some failing tests here that I'm not sure how to fix. It seems to be using ListChangeAppender to calculate the changes between a list and another class instance. It tries to convert the class instance to a list and fails with a ClassCastException.

The tests in question are:

org.javers.repository.mongo.EmbeddedMongoE2EWithRandomGeneratorTest/org.javers.core.JaversRepositoryE2ETest#should allow for property type change

org.javers.repository.mongo.EmbeddedMongoE2ETest/org.javers.core.JaversRepositoryE2ETest#should allow for property type change

Can you help me with those?

[bartoszwalacik]

huge PR :) give me a while

[franktominc]

No worries, take your time :)

[bartoszwalacik]

there are two problems with this PR

• You didn't provided tests for the new feature, so we don't know how it works and if it works.
• You have changed some existing tests which should not be affected by this change. For example, there is no reason to change SnapshotDifferIntegrationTest.groovy or JaversNapCategoryTreeIntegrationTest.groovy. The more tests you change, the higher risk that you break existing code of Javers users

[franktominc]

Regarding your points:

• I'll write some tests for it, however I'm afraid my groovy isn't that sharp, I'll try my best.
• The problem with the tests you mentioned was that they were testing for class equality, and this PR indeed broke some things. Now both ValueChange and ReferenceChange are abstract classes and each one of them has a final class for the added, updated and removed change.

Before the change:

After the change:

I updated those tests to reflect this change.