Follow up to bbe7fe41 to fix enum leakage across classes.

The original attempt didn't really fix the problem and wasn't testing the
problematic area. This commit corrected those issues in the original commit.

Also removed the private `enum_mapping_for` method. As `defined_enums` is now a
method, this method doesn't provide much value anymore.

1 files changed, 28 insertions, 7 deletions

diff --git a/activerecord/test/cases/enum_test.rb b/activerecord/test/cases/enum_test.rb
index 5157c272ca..3b2f0dfe07 100644
--- a/activerecord/test/cases/enum_test.rb
+++ b/activerecord/test/cases/enum_test.rb
@@ -252,17 +252,38 @@ class EnumTest < ActiveRecord::TestCase
   end
 
   test "enums are distinct per class" do
-    Plane = Class.new(ActiveRecord::Base) do
-      enum status: [:grounded, :operational]
+    klass1 = Class.new(ActiveRecord::Base) do
+      self.table_name = "books"
+      enum status: [:proposed, :written]
+    end
+
+    klass2 = Class.new(ActiveRecord::Base) do
+      self.table_name = "books"
+      enum status: [:drafted, :uploaded]
     end
-    assert_equal({ "proposed" => 0, "written" => 1, "published" => 2 }, Book.statuses)
-    assert_equal({ "grounded" => 0, "operational" => 1 }, Plane.statuses)
+
+    book1 = klass1.proposed.create!
+    book1.status = :written
+    assert_equal ['proposed', 'written'], book1.status_change
+
+    book2 = klass2.drafted.create!
+    book2.status = :uploaded
+    assert_equal ['drafted', 'uploaded'], book2.status_change
   end
 
   test "enums are inheritable" do
-    Encyclopedia = Class.new(Book) do
-      enum status: [:published, :reprinted]
+    subklass1 = Class.new(Book)
+
+    subklass2 = Class.new(Book) do
+      enum status: [:drafted, :uploaded]
     end
-    assert_equal({ "published" => 0, "reprinted" => 1 }, Encyclopedia.statuses)
+
+    book1 = subklass1.proposed.create!
+    book1.status = :written
+    assert_equal ['proposed', 'written'], book1.status_change
+
+    book2 = subklass2.drafted.create!
+    book2.status = :uploaded
+    assert_equal ['drafted', 'uploaded'], book2.status_change
   end
 end