[Fix rubocop#28] Fix Rake/Desc to avoid an error when task is not…

… a task definition

lib/rubocop/cop/rake/desc.rb

@@ -42,6 +42,7 @@ def on_task(node)
         private def task_with_desc?(node)
           parent, task = parent_and_task(node)
           return false unless parent
+          return true unless can_insert_desc_to?(parent)
 
           idx = parent.children.find_index(task) - 1
           desc_candidate = parent.children[idx]
@@ -63,6 +64,10 @@ def on_task(node)
             [parent, task_node]
           end
         end
+
+        private def can_insert_desc_to?(parent)
+          parent.begin_type? || parent.block_type? || parent.kwbegin_type?
+        end
       end
     end
   end

spec/rubocop/cop/rake/desc_spec.rb

@@ -34,6 +34,15 @@
     RUBY
   end
 
+  it 'register an offense for task in kwbegin' do
+    expect_offense(<<~RUBY)
+      begin
+        task :foo
+        ^^^^^^^^^ Describe the task with `desc` method.
+      end
+    RUBY
+  end
+
   it 'does not register an offense for task with desc' do
     expect_no_offenses(<<~RUBY)
       desc 'Do foo'
@@ -45,11 +54,17 @@
     RUBY
   end
 
-  it 'do not register an offense for the default task' do
+  it 'does not register an offense for the default task' do
     expect_no_offenses(<<~RUBY)
       task default: :spec
 
       task default: [:spec, :rubocop]
     RUBY
   end
+
+  it 'does not register an offense when `task` is not a definition' do
+    expect_no_offenses(<<~RUBY)
+      task.name
+    RUBY
+  end
 end