Add a test for numericality + money columns

18b2859 and a0f1221 fixed the numericality matcher so that it no longer
raises CouldNotSetAttributeError when used against numeric columns.
Unfortunately, the issue still existed for money columns.

This is fixed now, but we never explicitly tested for money columns, and
this commit adds that test.

NEWS.md

@@ -21,6 +21,9 @@
   a virtual attribute defined in an ActiveRecord model (that is, an attribute
   that is not present in the database but is defined using `attr_accessor`).
 
+* Add a test for `validate_numericality_of` so that it officially supports money
+  columns.
+
 ### Improvements
 
 * Improve failure messages and descriptions of all matchers across the board so

spec/support/unit/helpers/database_helpers.rb

@@ -9,10 +9,12 @@ def database_adapter
       Tests::Database.instance.adapter_name
     end
 
-    def database_supports_uuid_columns?
+    def postgresql?
       database_adapter == :postgresql
     end
-    alias_method :database_supports_array_columns?,
-      :database_supports_uuid_columns?
+
+    alias_method :database_supports_array_columns?, :postgresql?
+    alias_method :database_supports_uuid_columns?, :postgresql?
+    alias_method :database_supports_money_columns?, :postgresql?
   end
 end

spec/unit/shoulda/matchers/active_model/validate_numericality_of_matcher_spec.rb

@@ -179,6 +179,15 @@ def default_validation_values
           expect(record).to validate_numericality
         end
       end
+
+      if database_supports_money_columns?
+        context 'when the column is a money column' do
+          it 'accepts (and does not raise an AttributeChangedValueError)' do
+            record = build_record_validating_numericality(column_type: :money)
+            expect(record).to validate_numericality
+          end
+        end
+      end
     end
 
     context 'and not validating anything' do