Support enum definition with symbol values

Fix: rails#49981

Author: jean-francois-labbe

activerecord/lib/active_record/enum.rb

@@ -220,7 +220,7 @@ def enum(name, values = nil, **options)
 
     private
       def _enum(name, values, prefix: nil, suffix: nil, scopes: true, instance_methods: true, validate: false, **options)
-        assert_valid_enum_definition_values(values)
+        values = assert_valid_enum_definition_values(values)
         assert_valid_enum_options(options)
 
         # statuses = { }
@@ -341,6 +341,20 @@ def assert_valid_enum_definition_values(values)
           if values.keys.any?(&:blank?)
             raise ArgumentError, "Enum values #{values} must not contain a blank name."
           end
+
+          values = values.transform_values do |value|
+            value.is_a?(Symbol) ? value.name : value
+          end
+
+          values.each_value do |value|
+            case value
+            when String, Integer, true, false, nil
+              # noop
+            else
+              raise ArgumentError, "Enum values #{values} must be only booleans, integers, symbols or strings, got: #{value.class}"
+            end
+          end
+
         when Array
           if values.empty?
             raise ArgumentError, "Enum values #{values} must not be empty."
@@ -356,6 +370,8 @@ def assert_valid_enum_definition_values(values)
         else
           raise ArgumentError, "Enum values #{values} must be either a non-empty hash or an array."
         end
+
+        values
       end
 
       def assert_valid_enum_options(options)

activerecord/test/cases/enum_test.rb

@@ -493,6 +493,15 @@ def self.name; "Book"; end
 
     assert_match(/must not contain a blank name\.$/, e.message)
 
+    e = assert_raises(ArgumentError) do
+      Class.new(ActiveRecord::Base) do
+        self.table_name = "books"
+        enum :status, { proposed: Object.new, active: :active }
+      end
+    end
+
+    assert_match(/must be only booleans, integers, symbols or strings/, e.message)
+
     e = assert_raises(ArgumentError) do
       Class.new(ActiveRecord::Base) do
         self.table_name = "books"
@@ -715,6 +724,12 @@ def self.name; "Book"; end
     assert_equal "proposed", book.aliased_status
   end
 
+  test "enum with a hash with symbol values" do
+    book = Book.create!(symbol_status: :proposed)
+    assert_equal "proposed", book.symbol_status
+    assert_predicate book, :symbol_status_proposed?
+  end
+
   test "query state by predicate with prefix" do
     assert_predicate @book, :author_visibility_visible?
     assert_not_predicate @book, :author_visibility_invisible?

activerecord/test/models/book.rb

@@ -24,6 +24,7 @@ class Book < ActiveRecord::Base
   enum :difficulty, [:easy, :medium, :hard], suffix: :to_read
   enum :cover, { hard: "hard", soft: "soft" }
   enum :boolean_status, { enabled: true, disabled: false }
+  enum :symbol_status, { proposed: :proposed, published: :published }, prefix: true
 
   def published!
     super

activerecord/test/schema/schema.rb

@@ -138,6 +138,7 @@
     t.column :font_size, :integer, **default_zero
     t.column :difficulty, :integer, **default_zero
     t.column :cover, :string, default: "hard"
+    t.column :symbol_status, :string, default: "proposed"
     t.string :isbn
     t.string :external_id
     t.column :original_name, :string

guides/source/active_record_validations.md

@@ -917,7 +917,7 @@ A `:conditions` option can be used to specify additional conditions as a `WHERE`
 SQL fragment to limit the uniqueness constraint lookup:
 
 ```ruby
-validates :name, uniqueness: { conditions: -> { where(status: 'active') } }
+validates :name, uniqueness: { conditions: -> { where(status: "active") } }
 ```
 
 The default error message is _"has already been taken"_.