fix: service_broker validation_unique removel is reverted. Since it is used as guard before calling some http endpoint in check in service_broker_registration. Comments are added

Author: serdarozerr

app/models/runtime/domain.rb

@@ -97,6 +97,8 @@ def around_save
 
     def validate
       validates_presence :name
+      # Keep validates_unique to check across all Domain subclasses (STI: SharedDomain, PrivateDomain).
+      # Without it, exact name duplicates would be caught by name_overlaps? below with a misleading error message.
       validates_unique :name, dataset: Domain.dataset
 
       validates_format CloudController::DomainDecorator::DOMAIN_REGEX, :name,

app/models/services/service_broker.rb

@@ -25,7 +25,7 @@ def around_save
     rescue Sequel::UniqueConstraintViolation => e
       raise e unless e.message.include?('service_brokers_name_index')
 
-      errors.add(:name, Sequel.lit('Name must be unique'))
+      errors.add(:name, :unique)
       raise validation_failed_error
     end
 
@@ -34,6 +34,9 @@ def validate
       validates_presence :broker_url
       validates_presence :auth_username
       validates_presence :auth_password
+      # Keep validates_unique as a pre-guard for ServiceBrokerRegistration
+      # to avoid unnecessary HTTP calls to the broker if the name is not unique.
+      validates_unique :name, message: Sequel.lit('Name must be unique')
       validates_url :broker_url
       validates_url_no_basic_auth
     end

lib/services/service_brokers/service_broker_registration.rb

@@ -30,9 +30,6 @@ def create
         raise e
       end
       self
-    rescue Sequel::ValidationFailed
-      # Errors have been added to the broker model by around_save (e.g. unique constraint violations)
-      nil
     end
 
     def update
@@ -53,9 +50,6 @@ def update
         synchronize_services_and_plans!
       end
       self
-    rescue Sequel::ValidationFailed
-      # Errors have been added to the broker model by around_save (e.g. unique constraint violations)
-      nil
     end
 
     delegate :errors, to: :broker

spec/unit/controllers/services/service_brokers_controller_spec.rb

@@ -291,7 +291,6 @@ def stub_catalog(broker_url: nil, username: nil, password: nil)
           post '/v2/service_brokers', public_body
           expect(last_response).to have_status_code(201)
 
-          stub_catalog
           post '/v2/service_brokers', body
           expect(last_response).to have_status_code(400)
         end

spec/unit/models/services/service_broker_spec.rb

@@ -42,6 +42,7 @@ module VCAP::CloudController
       it { is_expected.to validate_presence :broker_url }
       it { is_expected.to validate_presence :auth_username }
       it { is_expected.to validate_presence :auth_password }
+      it { is_expected.to validate_uniqueness :name, message: Sequel.lit('Name must be unique') }
 
       it 'validates the url is a valid http/https url' do
         expect(broker).to be_valid