Deprecate and rename the keys for association restrict_dependent_destroy

Previously `has_one` and `has_many` associations were using the
`one` and `many` keys respectively. Both of these keys have special
meaning in I18n (they are considered to be pluralizations) so by
renaming them to `has_one` and `has_many` we make the messages more
explicit and most importantly they don't clash with linguistical
systems that need to validate translation keys (and their
pluralizations).

The `:'restrict_dependent_destroy.one'` key should be replaced with
`:'restrict_dependent_destroy.has_one'`, and
`:'restrict_dependent_destroy.many'` with
`:'restrict_dependent_destroy.has_many'`.

[Roque Pinel & Christopher Dell]

3 files changed, 18 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index ca27c9fdde..9f6c832c1b 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -16,7 +16,14 @@ module ActiveRecord
         when :restrict_with_error
           unless empty?
             record = klass.human_attribute_name(reflection.name).downcase
-            owner.errors.add(:base, :"restrict_dependent_destroy.many", record: record)
+            message = owner.errors.generate_message(:base, :'restrict_dependent_destroy.many', record: record, raise: true) rescue nil
+            if message
+              ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
+                The error key `:'restrict_dependent_destroy.many'` has been deprecated and will be removed in Rails 5.1.
+                Please use `:'restrict_dependent_destroy.has_many'` instead.
+              MESSAGE
+            end
+            owner.errors.add(:base, message || :'restrict_dependent_destroy.has_many', record: record)
             throw(:abort)
           end
 
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index 41a75b820e..5a92bc5e8a 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -12,7 +12,14 @@ module ActiveRecord
         when :restrict_with_error
           if load_target
             record = klass.human_attribute_name(reflection.name).downcase
-            owner.errors.add(:base, :"restrict_dependent_destroy.one", record: record)
+            message = owner.errors.generate_message(:base, :'restrict_dependent_destroy.one', record: record, raise: true) rescue nil
+            if message
+              ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
+                The error key `:'restrict_dependent_destroy.one'` has been deprecated and will be removed in Rails 5.1.
+                Please use `:'restrict_dependent_destroy.has_one'` instead.
+              MESSAGE
+            end
+            owner.errors.add(:base, message || :'restrict_dependent_destroy.has_one', record: record)
             throw(:abort)
           end
 
diff --git a/activerecord/lib/active_record/locale/en.yml b/activerecord/lib/active_record/locale/en.yml
index 8a3c27e6da..0b35027b2b 100644
--- a/activerecord/lib/active_record/locale/en.yml
+++ b/activerecord/lib/active_record/locale/en.yml
@@ -16,8 +16,8 @@ en:
       messages:
         record_invalid: "Validation failed: %{errors}"
         restrict_dependent_destroy:
-          one: "Cannot delete record because a dependent %{record} exists"
-          many: "Cannot delete record because dependent %{record} exist"
+          has_one: "Cannot delete record because a dependent %{record} exists"
+          has_many: "Cannot delete record because dependent %{record} exist"
         # Append your own errors here or at the model/attributes scope.
 
       # You can define own errors for models or model attributes.