Support it/test testing blocks as test cases

changelog/new_accept_it_test_block_as_testcase.md

@@ -0,0 +1 @@
+* [#238](https://github.com/rubocop/rubocop-minitest/pull/238): Support `it`/`test` testing blocks as test cases. ([@fatkodima][])

lib/rubocop/cop/minitest/assert_output.rb

@@ -36,8 +36,7 @@ def on_gvasgn(node)
         private
 
         def find_test_case(node)
-          def_ancestor = node.each_ancestor(:def).first
-          def_ancestor if test_case?(def_ancestor)
+          node.each_ancestor.find { |ancestor| test_case?(ancestor) }
         end
 
         def references_gvar?(assertion, gvar_name)

lib/rubocop/cop/mixin/minitest_exploration_helpers.rb

@@ -28,22 +28,23 @@ def test_class?(class_node)
       end
 
       def test_case?(node)
-        return false unless node&.def_type? && test_method?(node)
+        return false unless (node&.def_type? && test_method?(node)) ||
+                            (node&.block_type? && test_block?(node))
 
         class_ancestor = node.each_ancestor(:class).first
         test_class?(class_ancestor)
       end
 
       def test_cases(class_node, visibility_check: true)
-        test_cases = class_def_nodes(class_node).select do |def_node|
+        test_methods = class_def_nodes(class_node).select do |def_node|
           test_method?(def_node, visibility_check: visibility_check)
         end
 
         # Support Active Support's `test 'example' { ... }` method.
         # https://api.rubyonrails.org/classes/ActiveSupport/Testing/Declarative.html
-        test_blocks = class_node.each_descendant(:block).select { |block| block.method?(:test) || block.method?(:it) }
+        test_blocks = class_node.each_descendant(:block).select { |block_node| test_block?(block_node) }
 
-        test_cases + test_blocks
+        test_methods + test_blocks
       end
 
       def test_method?(def_node, visibility_check: true)
@@ -52,6 +53,10 @@ def test_method?(def_node, visibility_check: true)
         test_case_name?(def_node.method_name) && !def_node.arguments?
       end
 
+      def test_block?(block_node)
+        block_node.method?(:test) || block_node.method?(:it)
+      end
+
       def lifecycle_hooks(class_node)
         class_def_nodes(class_node)
           .select { |def_node| lifecycle_hook_method?(def_node) }

test/rubocop/cop/minitest/assert_output_test.rb

@@ -17,6 +17,22 @@ def test_do_something
     RUBY
   end
 
+  def test_registers_offense_when_mutating_output_global_variable_in_it_block_form
+    assert_offense(<<~RUBY)
+      class FooTest < Minitest::Test
+        describe Foo do
+          it "does something" do
+            $stdout = StringIO.new
+            puts object.method
+            $stdout.rewind
+            assert_match expected, $stdout.read
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `assert_output` instead of mutating $stdout.
+          end
+        end
+      end
+    RUBY
+  end
+
   def test_does_not_register_offense_when_not_inside_test_case
     assert_no_offenses(<<~RUBY)
       class FooTest < Minitest::Test