Add test for private method inheritance visibility

spec/features/detects_private_method_spec.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require_relative '../../lib/lowkey'
+
+RSpec.describe 'Private method visibility' do
+  let(:file_path) { 'spec/fixtures/visibility_test.rb' }
+  let(:file_proxy) { Lowkey.load(file_path, cache: false) }
+
+  it 'detects that a class has private methods' do
+    target_class = file_proxy["VisibilityTest"] 
+
+    expect(target_class.private_start_line).not_to be_nil
+  end
+end

spec/fixtures/visibility_test.rb

@@ -0,0 +1,11 @@
+class VisibilityTest
+  def public_greet
+    "hello"
+  end
+
+  private
+
+  def private_greet
+    "hello"
+  end
+end