Add Support for classes defined with compact style

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 * [#362](https://github.com/rubocop-hq/rubocop-rails/pull/362): Add new `Rails/WhereEquals` cop. ([@eugeneius][])
 
+### Bug fixes
+
+* [#364](https://github.com/rubocop-hq/rubocop-rails/pull/364): Fix a problem that `Rails/UniqueValidationWithoutIndex` doesn't work in classes defined with compact style. ([@sinsoku][])
+
 ## 2.8.1 (2020-09-16)
 
 ### Bug fixes

lib/rubocop/cop/mixin/active_record_helper.rb

@@ -35,10 +35,11 @@ def table_name(class_node)
         table_name = find_set_table_name(class_node).to_a.last&.first_argument
         return table_name.value.to_s if table_name
 
-        namespaces = class_node.each_ancestor(:class, :module)
-        [class_node, *namespaces]
+        class_nodes = class_node.defined_module.each_node
+        namespaces = class_node.each_ancestor(:class, :module).map(&:identifier)
+        [*class_nodes, *namespaces]
           .reverse
-          .map { |klass| klass.identifier.children[1] }.join('_')
+          .map { |node| node.children[1] }.join('_')
           .tableize
       end
 

spec/rubocop/cop/active_record_helper_spec.rb

@@ -36,4 +36,60 @@
       it { is_expected.to be_nil }
     end
   end
+
+  describe '#table_name' do
+    subject { cop.table_name(class_node) }
+
+    context 'when the class is simple' do
+      let(:class_node) { parse_source(<<~RUBY).ast }
+        class User
+        end
+      RUBY
+
+      it { is_expected.to eq 'users' }
+    end
+
+    context 'when the self.table_name is set' do
+      let(:class_node) { parse_source(<<~RUBY).ast }
+        class Foo
+          self.table_name = 'bar'
+        end
+      RUBY
+
+      it { is_expected.to eq 'bar' }
+    end
+
+    context 'when the class is defined in a module' do
+      let(:class_node) { parse_source(<<~RUBY).ast.each_child_node(:class).first }
+        module Admin
+          class User
+          end
+        end
+      RUBY
+
+      it { is_expected.to eq 'admin_users' }
+    end
+
+    context 'when the class is defined in nested modules' do
+      let(:class_node) { parse_source(<<~RUBY).ast.each_descendant(:class).first }
+        module Cop
+          module Admin
+            class User
+            end
+          end
+        end
+      RUBY
+
+      it { is_expected.to eq 'cop_admin_users' }
+    end
+
+    context 'when the class is defined with compact style' do
+      let(:class_node) { parse_source(<<~RUBY).ast }
+        class Cop::Admin::User
+        end
+      RUBY
+
+      it { is_expected.to eq 'cop_admin_users' }
+    end
+  end
 end

spec/rubocop/cop/rails/unique_validation_without_index_spec.rb

@@ -393,7 +393,7 @@ class User
       end
     end
 
-    context 'with nested class' do
+    context 'with namespaced model' do
       let(:schema) { <<~RUBY }
         ActiveRecord::Schema.define(version: 2020_02_02_075409) do
           create_table "admin_users", force: :cascade do |t|
@@ -402,7 +402,7 @@ class User
         end
       RUBY
 
-      it 'registers an offense' do
+      it 'registers an offense for nested class' do
         expect_offense(<<~RUBY)
           module Admin
             class User
@@ -412,6 +412,15 @@ class User
           end
         RUBY
       end
+
+      it 'registers an offense for compact styled class' do
+        expect_offense(<<~RUBY)
+          class Admin::User
+            validates :account, uniqueness: true
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Uniqueness validation should be with a unique index.
+          end
+        RUBY
+      end
     end
 
     context 'with expression indexes' do