DRY `activerecord/lib/active_record/core.rb` and fix tests

- Move
  ```
  filter_attributes = self.filter_attributes.map(&:to_s).to_set

  filter_attributes.include?(attribute_name) && !read_attribute(attribute_name).nil?
  ```
  to private method.

- Fix tests in `activerecord/test/cases/filter_attributes_test.rb`
  - Ensure that `teardown` sets `ActiveRecord::Base.filter_attributes` to
    previous state.

  - Ensure that `Admin::Account.filter_attributes` is set to previous
    state in the "filter_attributes could be overwritten by models" test.

Follow up #33756

1 files changed, 18 insertions, 14 deletions

diff --git a/activerecord/test/cases/filter_attributes_test.rb b/activerecord/test/cases/filter_attributes_test.rb
index f88cecfe2b..af5badd87d 100644
--- a/activerecord/test/cases/filter_attributes_test.rb
+++ b/activerecord/test/cases/filter_attributes_test.rb
@@ -10,11 +10,12 @@ class FilterAttributesTest < ActiveRecord::TestCase
   fixtures :"admin/users", :"admin/accounts"
 
   setup do
+    @previous_filter_attributes = ActiveRecord::Base.filter_attributes
     ActiveRecord::Base.filter_attributes = [:name]
   end
 
   teardown do
-    ActiveRecord::Base.filter_attributes = []
+    ActiveRecord::Base.filter_attributes = @previous_filter_attributes
   end
 
   test "filter_attributes" do
@@ -35,20 +36,23 @@ class FilterAttributesTest < ActiveRecord::TestCase
       assert_equal 1, account.inspect.scan("[FILTERED]").length
     end
 
-    Admin::Account.filter_attributes = []
-
-    # Above changes should not impact other models
-    Admin::User.all.each do |user|
-      assert_includes user.inspect, "name: [FILTERED]"
-      assert_equal 1, user.inspect.scan("[FILTERED]").length
+    begin
+      previous_account_filter_attributes = Admin::Account.filter_attributes
+      Admin::Account.filter_attributes = []
+
+      # Above changes should not impact other models
+      Admin::User.all.each do |user|
+        assert_includes user.inspect, "name: [FILTERED]"
+        assert_equal 1, user.inspect.scan("[FILTERED]").length
+      end
+
+      Admin::Account.all.each do |account|
+        assert_not_includes account.inspect, "name: [FILTERED]"
+        assert_equal 0, account.inspect.scan("[FILTERED]").length
+      end
+    ensure
+      Admin::Account.filter_attributes = previous_account_filter_attributes
     end
-
-    Admin::Account.all.each do |account|
-      assert_not_includes account.inspect, "name: [FILTERED]"
-      assert_equal 0, account.inspect.scan("[FILTERED]").length
-    end
-
-    Admin::Account.filter_attributes = [:name]
   end
 
   test "filter_attributes should not filter nil value" do