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Testing RSpec DSL Permission Handling in Pundit

This test suite validates the RSpec DSL implementation in Pundit, focusing on permission handling and policy testing. It ensures proper functionality of permission checks and error handling within the authorization framework.

Test Coverage Overview

The test suite provides comprehensive coverage of Pundit’s RSpec DSL functionality, particularly focusing on permission handling and policy validation. Key areas tested include:

Permission metadata handling with and without focus tags
Policy permission verification through the permit matcher
Error handling for improperly wrapped permission tests
Positive and negative permission assertions

Implementation Analysis

The testing approach utilizes RSpec’s behavior-driven development patterns with extensive use of doubles and mocks. The implementation leverages RSpec’s metadata functionality for permission tracking and employs nested contexts to organize different test scenarios.

Uses class_double for RSpec integration testing
Implements custom DSL extensions for permission testing
Employs context-based test organization

Technical Details

RSpec as the primary testing framework
Pundit::RSpec::PolicyExampleGroup for policy testing
Custom matchers for permission verification
Double objects for user and post models
Integration with RSpec’s metadata system

Best Practices Demonstrated

The test suite exemplifies high-quality testing practices through well-structured test organization and comprehensive error handling. Notable practices include:

Descriptive error messages for debugging
Proper test isolation using let blocks
Consistent testing patterns for permissions
Clear separation of positive and negative test cases

varvet/pundit

spec/rspec_dsl_spec.rb

            
# frozen_string_literal: true

require "spec_helper"

RSpec.describe "Pundit RSpec DSL" do
  include Pundit::RSpec::PolicyExampleGroup

  let(:fake_rspec) do
    double = class_double(RSpec::ExampleGroups)
    double.extend(::Pundit::RSpec::DSL)
    double
  end
  let(:block) { proc { "block content" } }

  let(:user) { double }
  let(:other_user) { double }
  let(:post) { Post.new(user) }
  let(:policy) { PostPolicy }

  it "calls describe with the correct metadata and without :focus" do
    expected_metadata = { permissions: %i[item1 item2], caller: instance_of(Array) }
    expect(fake_rspec).to receive(:describe).with("item1 and item2", match(expected_metadata)) do |&block|
      expect(block.call).to eq("block content")
    end

    fake_rspec.permissions(:item1, :item2, &block)
  end

  it "calls describe with the correct metadata and with :focus" do
    expected_metadata = { permissions: %i[item1 item2], caller: instance_of(Array), focus: true }
    expect(fake_rspec).to receive(:describe).with("item1 and item2", match(expected_metadata)) do |&block|
      expect(block.call).to eq("block content")
    end

    fake_rspec.permissions(:item1, :item2, :focus, &block)
  end

  describe "#permit" do
    context "when not appropriately wrapped in permissions" do
      it "raises a descriptive error" do
        expect do
          expect(policy).to permit(user, post)
        end.to raise_error(KeyError, <<~MSG.strip)
          No permissions in example metadata, did you forget to wrap with `permissions :show?, ...`?
        MSG
      end
    end

    permissions :edit?, :update? do
      it "succeeds when action is permitted" do
        expect(policy).to permit(user, post)
      end

      context "when it fails" do
        it "fails with a descriptive error message" do
          expect do
            expect(policy).to permit(other_user, post)
          end.to raise_error(RSpec::Expectations::ExpectationNotMetError, <<~MSG.strip)
            Expected PostPolicy to grant edit? and update? on Post but edit? and update? were not granted
          MSG
        end
      end

      context "when negated" do
        it "succeeds when action is not permitted" do
          expect(policy).not_to permit(other_user, post)
        end

        context "when it fails" do
          it "fails with a descriptive error message" do
            expect do
              expect(policy).not_to permit(user, post)
            end.to raise_error(RSpec::Expectations::ExpectationNotMetError, <<~MSG.strip)
              Expected PostPolicy not to grant edit? and update? on Post but edit? and update? were granted
            MSG
          end
        end
      end
    end
  end
end