Rails 6.0.0.beta2: breaking change in case sensitive uniqueness validator

[tagliala]

Steps to reproduce*

rake

Expected behavior*

Test pass

Actual behavior*

Failure:
ActiveRecord::UniquenessValidatorTest#test_uniqueness_client_side_hash_with_existing_record [~/dev/client_side_validations/test/active_record/cases/test_uniqueness_validator.rb:31]:
--- expected
+++ actual
@@ -1 +1 @@
-{:message=>"has already been taken", :case_sensitive=>true, :id=>1}
+{:message=>"has already been taken", :case_sensitive=>nil, :id=>1}

System configuration*

Rails version:
6.0.0.beta2

Ruby version:
2.6.1

Client Side Validations version:
master

Code snippet from your model of the validations*

N/A

The whole form code from your template*

N/A

The resulting HTML*

N/A

Browser's development console output*

Please confirm that your browser's development console does not contain errors.
N/A

Additional JavaScript Libraries*

If your issue depends on other JavaScript libraries, please list them here. E.g: Bootstrap Modal v3.3.7, jQuery UI Datepicker 1.12.4.
N/A

Repository demostrating the issue

N/A

---

* Failure to include this requirement will result in the issue being closed.

[tagliala]

Ref: rails/rails@6cb176c

[tagliala]

⚠️ Potential Breaking Change!

The client-side uniqueness validation was ignoring the case_sensitive: true parameter.

Scenario

• User Model
• Nested Profile model with email fields with uniqueness attribute
• Email 1: "[email protected]"
• Email 2: "[email protected]"

Previous behavior

• Show a validation error

New behavior

• Do not show a validation error