Merge pull request #1018 from koic/fix_false_positive_for_rspec_empty_example_group

Fix a false positive for `RSpec/EmptyExampleGroup`

Author: pirj

CHANGELOG.md

@@ -4,8 +4,9 @@
 
 * Move our documentation from rubocop-rspec.readthedocs.io to docs.rubocop.org/rubocop-rspec. ([@bquorning][])
 * Add `RSpec/RepeatedIncludeExample` cop. ([@biinari][])
-* Fix false positives in `RSpec/EmptyExampleGroup`. ([@pirj][])
 * Add `RSpec/StubbedMock` cop. ([@bquorning][], [@pirj][])
+* Fix false positives in `RSpec/EmptyExampleGroup`. ([@pirj][])
+* Fix a false positive for `RSpec/EmptyExampleGroup` when example is defined in an `if` branch. ([@koic][])
 
 ## 1.43.2 (2020-08-25)
 
@@ -561,3 +562,4 @@ Compatibility release so users can upgrade RuboCop to 0.51.0. No new features.
 [@jtannas]: https://github.com/jtannas
 [@mockdeep]: https://github.com/mockdeep
 [@biinari]: https://github.com/biinari
+[@koic]: https://github.com/koic

lib/rubocop/cop/rspec/empty_example_group.rb

@@ -164,12 +164,35 @@ def on_block(node)
           return if node.each_ancestor(:block).any? { |block| example?(block) }
 
           example_group_body(node) do |body|
-            add_offense(node.send_node) unless examples?(body)
+            add_offense(node.send_node) if offensive?(body)
           end
         end
 
         private
 
+        def offensive?(body)
+          return true unless body
+          return false if conditionals_with_examples?(body)
+
+          if body.if_type?
+            !examples_in_branches?(body)
+          else
+            !examples?(body)
+          end
+        end
+
+        def conditionals_with_examples?(body)
+          return unless body.begin_type?
+
+          body.each_descendant(:if).any? do |if_node|
+            examples_in_branches?(if_node)
+          end
+        end
+
+        def examples_in_branches?(if_node)
+          if_node.branches.any? { |branch| examples?(branch) }
+        end
+
         def custom_include?(method_name)
           custom_include_methods.include?(method_name)
         end

spec/rubocop/cop/rspec/empty_example_group_spec.rb

@@ -54,6 +54,62 @@
     RUBY
   end
 
+  it 'ignores example group with examples defined in `if` branches' do
+    expect_no_offenses(<<~RUBY)
+      describe 'Ruby 2.3 syntax' do
+        version = 2.3
+
+        if RUBY_VERSION >= version
+          it { expect(use_safe_navigation_operator?(code)).to be(true) }
+        else
+          warn 'Ruby < 2.3 is barely supported, please use a newer version for development.'
+        end
+      end
+    RUBY
+  end
+
+  it 'ignores example group with examples but no examples in `if` branches' do
+    expect_no_offenses(<<~RUBY)
+      describe 'Ruby 2.3 syntax' do
+        version = 2.3
+
+        if RUBY_VERSION < version
+          warn 'Ruby < 2.3 is barely supported, please use a newer version for development.'
+        end
+
+        it { expect(newspaper(page)).to have_ads }
+      end
+    RUBY
+  end
+
+  it 'flags an empty example group with no examples defined in `if` branches' do
+    expect_offense(<<~RUBY)
+      describe 'Ruby 2.3 syntax' do
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^ Empty example group detected.
+        version = 2.3
+
+        if RUBY_VERSION >= version
+          warn 'Ruby > 2.3 is supported'
+        else
+          warn 'Ruby < 2.3 is barely supported, please use a newer version for development.'
+        end
+      end
+
+      describe 'Ruby 2.3 syntax' do
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^ Empty example group detected.
+        if RUBY_VERSION < 2.3
+        else
+        end
+      end
+
+      describe 'Ruby 2.3 syntax' do
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^ Empty example group detected.
+        if RUBY_VERSION >= 2.3
+        end
+      end
+    RUBY
+  end
+
   it 'ignores example group with examples defined in iterator' do
     expect_no_offenses(<<~RUBY)
       describe 'RuboCop monthly' do