Fix error when block method has no arguments.

Author: htanata

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## master (unreleased)
 
+* Fix error when block method has no arguments.
+
 ## 0.0.2
 
 * Support symbols passed as metadata, e.g:

lib/rubocop/cop/rspec/focused.rb

@@ -40,10 +40,12 @@ def on_block(node)
         def focus_set_to_true?(metadata)
           return unless metadata
 
-          metadata.include?(s(:sym, :focus)) ||
+          metadata.include?(s(:sym, :focus)) || (
+            metadata.last &&
             metadata.last.children.any? do |pair|
               pair == s(:pair, s(:sym, :focus), s(:true))
             end
+          )
         end
       end
     end

spec/lib/rubocop/cop/rspec/focused_spec.rb

@@ -32,4 +32,13 @@
     expect(cop.offenses.map(&:line).sort).to eq([1])
     expect(cop.messages).to eq([described_class::MESSAGE])
   end
+
+  it 'does not raise error on block without arguments' do
+    inspect_source(cop, ['it "does something" do',
+                         '  expect(foo).to be_empty',
+                         'end'])
+    expect(cop.offenses.size).to eq(0)
+    expect(cop.offenses.map(&:line).sort).to be_empty
+    expect(cop.messages).to be_empty
+  end
 end