Add ability to support case-insensitive enum validation

[James Navin]

The JSON Schema spec treats enum validation as case-sensitive - http://json-schema.org/latest/json-schema-validation.html#anchor76

There are some cases where case-insensitive validation would be desirable.

e.g.

java.lang.AssertionError: Validation errors found.
    * atlassian-scheduler
        - schedule a new job    
            [ERROR] [Path '/notificationMethod'] Instance value ("unknown") not found in enum (possible values: ["SQS","HTTP_GET","HTTP_POST","HTTP_PUT","HTTP_DELETE","NONE","UNKNOWN"])
            [ERROR] [Path '/type'] Instance value ("interval") not found in enum (possible values: ["SINGLE","CRON","INTERVAL","UNKNOWN"])

[James Navin]

Ideally we could support this using the log levels mechanism rather than introducing a new configuration mechanism.

Some ideas:

• Detect the enum validation failure and then perform case-insensitive validation, then emit messages at the correct level
• Perform both case sensitive and case insensitive validations and emit both messages at configured levels

[Nikhil Raman]

How does the framework know that user would like to perform case insensitive validation in case of failure? Also people may not look into log unless something failing in CI. I prefer to have a config options like enableCaseInsensitiveEnumValidation()

[Sven Döring]

That feature would come in handy for us at this point.

But I see a major problem. What if case-insensitivity is good for some enums but not for others in the same API definition?