Add negative scopes for all enum values (#35381)

Add negative scopes for all enum values

activerecord/CHANGELOG.md

+*   Add negative scopes for all enum values.
+
+    Example:
+    
+        class Post < ActiveRecord::Base
+          enum status: %i[ drafted active trashed ]
+        end
+  
+        Post.not_drafted # => where.not(status: :drafted)
+        Post.not_active  # => where.not(status: :active)
+        Post.not_trashed # => where.not(status: :trashed)
+    
+    *DHH*
+
 *   Fix different `count` calculation when using `size` with manual `select` with DISTINCT.
 
     Fixes #35214.

activerecord/lib/active_record/enum.rb

@@ -31,7 +31,9 @@ module ActiveRecord
   # as well. With the above example:
   #
   #   Conversation.active
+  #   Conversation.not_active
   #   Conversation.archived
+  #   Conversation.not_archived
   #
   # Of course, you can also query them directly if the scopes don't fit your
   # needs:
@@ -196,9 +198,13 @@ def enum(definitions)
             define_method("#{value_method_name}!") { update!(attr => value) }
 
             # scope :active, -> { where(status: 0) }
+            # scope :not_active, -> { where.not(status: 0) }
             if enum_scopes != false
               klass.send(:detect_enum_conflict!, name, value_method_name, true)
               klass.scope value_method_name, -> { where(attr => value) }
+
+              klass.send(:detect_enum_conflict!, name, "not_#{value_method_name}", true)
+              klass.scope "not_#{value_method_name}", -> { where.not(attr => value) }
             end
           end
         end

activerecord/test/cases/enum_test.rb

@@ -43,6 +43,11 @@ class EnumTest < ActiveRecord::TestCase
     assert_equal books(:ddd), Book.forgotten.first
     assert_equal books(:rfr), authors(:david).unpublished_books.first
   end
+  
+  test "find via negative scope" do
+    assert Book.not_published.exclude?(@book)
+    assert Book.not_proposed.include?(@book)
+  end
 
   test "find via where with values" do
     published, written = Book.statuses[:published], Book.statuses[:written]