Adds Rubocop rule to enforce class_methods over module ClassMethods

1 files changed, 66 insertions, 0 deletions

diff --git a/spec/rubocop/cop/prefer_class_methods_over_module_spec.rb b/spec/rubocop/cop/prefer_class_methods_over_module_spec.rb
new file mode 100644
index 00000000000..64b1f1b948d
--- /dev/null
+++ b/spec/rubocop/cop/prefer_class_methods_over_module_spec.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'rubocop'
+require 'rubocop/rspec/support'
+require_relative '../../../rubocop/cop/prefer_class_methods_over_module'
+
+describe RuboCop::Cop::PreferClassMethodsOverModule do
+  include CopHelper
+
+  subject(:cop) { described_class.new }
+
+  it 'flags violation when using ClassMethods' do
+    expect_offense(<<~RUBY)
+      module Foo
+        module ClassMethods
+        ^^^^^^^^^^^^^^^^^^^ Do not use module ClassMethods, use class_methods block instead.
+          def a_class_method
+          end
+        end
+      end
+    RUBY
+  end
+
+  it "doesn't flag violation when using class_methods" do
+    expect_no_offenses(<<~RUBY)
+      module Foo
+        class_methods do
+          def a_class_method
+          end
+        end
+      end
+    RUBY
+  end
+
+  it "doesn't flag violation when not using either class_methods or ClassMethods" do
+    expect_no_offenses(<<~RUBY)
+      module Foo
+        def a_method
+        end
+      end
+    RUBY
+  end
+
+  it 'autocorrects ClassMethods into class_methods' do
+    source = <<~RUBY
+      module Foo
+        module ClassMethods
+          def a_class_method
+          end
+        end
+      end
+    RUBY
+    autocorrected = autocorrect_source(source)
+
+    expected_source = <<~RUBY
+      module Foo
+        class_methods do
+          def a_class_method
+          end
+        end
+      end
+    RUBY
+    expect(autocorrected).to eql(expected_source)
+  end
+end