Guard modifier removal to statement calls

Assisted-By: devx/eb25d669-b4ee-4e28-9b69-129b45e1e178

Author: KaanOzkan

lib/spoom/deadcode/remover.rb

@@ -74,8 +74,8 @@ def apply_edit
         #
         # Modifiers are matched structurally rather than from a fixed list, so user-defined ones are
         # handled too. A call only counts as a modifier when the `def` is its sole argument and it takes
-        # no block, so we never remove a call that does more than wrap the method (e.g.
-        # `register(:thing, def foo; end)`).
+        # no block and is a standalone statement, so we never remove a call that does more than wrap
+        # the method (e.g. `register(:thing, def foo; end)` or `FOO = register(def foo; end)`).
         #: (Prism::DefNode def_node) -> NodeContext?
         def modifier_call_context(def_node)
           wrapped = def_node #: Prism::Node
@@ -103,6 +103,7 @@ def modifier_call_context(def_node)
             end
           end
           return unless outer_call && outer_nesting
+          return unless outer_nesting.last.is_a?(Prism::StatementsNode)
 
           NodeContext.new(@old_source, @node_context.comments, outer_call, outer_nesting)
         end

test/spoom/deadcode/remover_test.rb

@@ -1120,6 +1120,29 @@ def keep; end
         RB
       end
 
+      def test_keeps_parent_expression_when_sole_argument_call_is_not_a_statement
+        res = remove(<<~RB, "bar")
+          class Foo
+            FOO = register(
+              def bar
+                x
+              end
+            )
+
+            def keep; end
+          end
+        RB
+
+        assert_equal(<<~RB, res)
+          class Foo
+            FOO = register(
+            )
+
+            def keep; end
+          end
+        RB
+      end
+
       def test_removes_node_sig_and_comments
         res = remove(<<~RB, "bar")
           class Foo