Fix Generation of proper migration when

  ActiveRecord::Base.pluralize_table_names = false.

  Previously, generation a migration like this:

      rails g migration add_column_name_to_user name

  would not generating the correct table name.

Fixes #13426.

2 files changed, 54 insertions, 0 deletions

diff --git a/railties/lib/rails/generators/generated_attribute.rb b/railties/lib/rails/generators/generated_attribute.rb
index 5e2784c4b0..c5326d70d1 100644
--- a/railties/lib/rails/generators/generated_attribute.rb
+++ b/railties/lib/rails/generators/generated_attribute.rb
@@ -94,6 +94,10 @@ module Rails
         name.sub(/_id$/, '').pluralize
       end
 
+      def singular_name
+        name.sub(/_id$/, '').singularize
+      end
+
       def human_name
         name.humanize
       end
diff --git a/railties/test/generators/migration_generator_test.rb b/railties/test/generators/migration_generator_test.rb
index d876597944..6fac643ed0 100644
--- a/railties/test/generators/migration_generator_test.rb
+++ b/railties/test/generators/migration_generator_test.rb
@@ -197,4 +197,54 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
   def test_properly_identifies_usage_file
     assert generator_class.send(:usage_path)
   end
+
+  def test_migration_with_singular_table_name
+    with_singular_table_name do
+      migration = "add_title_body_to_post"
+      run_generator [migration, 'title:string']
+      assert_migration "db/migrate/#{migration}.rb" do |content|
+        assert_method :change, content do |change|
+          assert_match(/add_column :post, :title, :string/, change)
+        end
+      end
+    end
+  end
+
+  def test_create_join_table_migration_with_singular_table_name
+    with_singular_table_name do
+      migration = "add_media_join_table"
+      run_generator [migration, "artist_id", "music:uniq"]
+
+      assert_migration "db/migrate/#{migration}.rb" do |content|
+        assert_method :change, content do |change|
+          assert_match(/create_join_table :artist, :music/, change)
+          assert_match(/# t.index \[:artist_id, :music_id\]/, change)
+          assert_match(/  t.index \[:music_id, :artist_id\], unique: true/, change)
+        end
+      end
+    end
+  end
+
+  def test_create_table_migration_with_singular_table_name
+    with_singular_table_name do
+      run_generator ["create_book", "title:string", "content:text"]
+      assert_migration "db/migrate/create_book.rb" do |content|
+        assert_method :change, content do |change|
+          assert_match(/create_table :book/, change)
+          assert_match(/  t\.string :title/, change)
+          assert_match(/  t\.text :content/, change)
+        end
+      end
+    end
+  end
+
+  private
+
+    def with_singular_table_name
+      old_state = ActiveRecord::Base.pluralize_table_names
+      ActiveRecord::Base.pluralize_table_names = false
+      yield
+    ensure
+      ActiveRecord::Base.pluralize_table_names = old_state
+    end
 end