[AVRO-2294] The schema validator reports false negatives for any incompatible change to an enum type

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.8.2
• Component/s: java
• Assignee: Unassigned
• Reporter: Ryan Sobol
• Created: 27/Dec/18 22:22
• Updated: 27/Dec/18 22:25

Description

The schema validator reports false negatives for any incompatible change to an enum type. I found this bug when invoking the SchemaValidatorBuilder.mutualReadStrategy() method via Confluent's Schema Registry.

This bug can be traced to the Symbol.hasErrors() method. When it is invoked with a Symbol.EnumAdjustAction object, it always (and therefore incorrectly) returns false. This is a problem because these objects can definitely have errors—masquerading along side adjustments.

The root cause of this bug has to do with objects of the Symbol.EnumAdjustAction class being assigned a Kind.EXPLICIT_ACTION kind. This kind informs the Symbol.hasErrors() method to always return false without checking if there are any errors hiding inside the object's adjustments.

As best I understand, there are a few possible solutions:

1. Fix the Symbol.hasErrors() method so it checks the objects adjustments.
2. Fix the Symbol.EnumAdjustAction class so its objects have a different kind.
3. Fix both 1 and 2.

I'm not 100% familiar with the intention of the Symbol class. However, if given a little guidance on the preferred solution, I'm happy to submit a pull request to fix the bug.