Add test for view "Helper" module to improve coverage

spec/helper_spec.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe Pundit::Helper do
+  let(:user) { double }
+  let(:post) { Post.new(user) }
+  let(:view) { PostsView.new(user, post) }
+
+  describe ".policy_scope" do
+    it "returns an instantiated policy scope given a plain model class" do
+      expect(view.policy_scope(Post)).to eq :published
+    end
+
+    it "raises an original error with a policy scope that contains argument error" do
+      expect { view.policy_scope(user, Post) }.to raise_error(ArgumentError)
+    end
+
+    it "raises an exception if nil object given" do
+      expect { view.policy_scope(nil) }.to raise_error(Pundit::NotDefinedError, "Cannot scope NilClass")
+    end
+  end
+end

spec/spec_helper.rb

@@ -216,6 +216,22 @@ def initialize(current_user, action_name, params)
   end
 end
 
+class PostsView
+  include Pundit::Authorization
+  include Pundit::Helper
+  # Mark protected methods public so they may be called in test
+  # rubocop:disable Style/AccessModifierDeclarations
+  public(*Pundit::Authorization.private_instance_methods)
+  # rubocop:enable Style/AccessModifierDeclarations
+
+  attr_reader :current_user, :posts
+
+  def initialize(current_user, posts)
+    @current_user = current_user
+    @posts = posts
+  end
+end
+
 class NilClassPolicy < Struct.new(:user, :record)
   class Scope
     def initialize(*)