Add regression test for view-level policy_scope

See 87d859a and #207.

Effectively `policy_scope` in the view should not make the controller consider itself as scoped.

spec/pundit/helper_spec.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe Pundit::Helper do
+  let(:user) { double }
+  let(:controller) { Controller.new(user, "update", double) }
+  let(:view) { Controller::View.new(controller) }
+
+  describe "#policy_scope" do
+    it "doesn't flip pundit_policy_scoped?" do
+      scoped = view.policy_scope(Post)
+
+      expect(scoped).to be(Post.published)
+      expect(controller).not_to be_pundit_policy_scoped
+    end
+  end
+end

spec/support/lib/controller.rb

@@ -1,14 +1,36 @@
 # frozen_string_literal: true
 
 class Controller
+  attr_reader :current_user, :action_name, :params
+
+  class View
+    def initialize(controller)
+      @controller = controller
+    end
+
+    attr_reader :controller
+  end
+
+  class << self
+    def helper(mod)
+      View.include(mod)
+    end
+
+    def helper_method(method)
+      View.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+        def #{method}(*args, **kwargs, &block)
+          controller.send(:#{method}, *args, **kwargs, &block)
+        end
+      RUBY
+    end
+  end
+
   include Pundit::Authorization
   # Mark protected methods public so they may be called in test
   # rubocop:disable Style/AccessModifierDeclarations
   public(*Pundit::Authorization.protected_instance_methods)
   # rubocop:enable Style/AccessModifierDeclarations
 
-  attr_reader :current_user, :action_name, :params
-
   def initialize(current_user, action_name, params)
     @current_user = current_user
     @action_name = action_name