Merge pull request #655 from sunny/migration-class-name-ignores-gem-n…

…ame-in-path

Ignore gem name in path for `MigrationClassName`

changelog/fix_ignore_gem_name_in_path_for_migration_class_name.md

@@ -0,0 +1 @@
+* [#656](https://github.com/rubocop/rubocop-rails/issues/656): Ignore gem name in paths for `Rails/MigrationClassName`. ([@sunny][])

lib/rubocop/cop/rails/migration_class_name.rb

@@ -26,9 +26,10 @@ class MigrationClassName < Base
         def on_class(node)
           snake_class_name = to_snakecase(node.identifier.source)
 
-          return if snake_class_name == basename_without_timestamp
+          basename = basename_without_timestamp_and_suffix
+          return if snake_class_name == basename
 
-          corrected_class_name = to_camelcase(basename_without_timestamp)
+          corrected_class_name = to_camelcase(basename)
           message = format(MSG, corrected_class_name: corrected_class_name)
 
           add_offense(node.identifier, message: message) do |corrector|
@@ -38,12 +39,18 @@ def on_class(node)
 
         private
 
-        def basename_without_timestamp
+        def basename_without_timestamp_and_suffix
           filepath = processed_source.file_path
           basename = File.basename(filepath, '.rb')
+          basename = remove_gem_suffix(basename)
           basename.sub(/\A\d+_/, '')
         end
 
+        # e.g.: from `add_blobs.active_storage` to `add_blobs`.
+        def remove_gem_suffix(file_name)
+          file_name.sub(/\..+\z/, '')
+        end
+
         def to_camelcase(word)
           word.split('_').map(&:capitalize).join
         end

spec/rubocop/cop/rails/migration_class_name_spec.rb

@@ -26,4 +26,15 @@ class CreateUsers < ActiveRecord::Migration[7.0]
       RUBY
     end
   end
+
+  context 'when the class name contains a dot in its file name' do
+    let(:filename) { 'db/migrate/20220101050505_add_blobs.active_storage.rb' }
+
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY, filename)
+        class AddBlobs < ActiveRecord::Migration[7.0]
+        end
+      RUBY
+    end
+  end
 end