Refactoring: Add possibility to write tests for custom Zammad rubocop cops.

spec/rubocop/cop/zammad/have_no_over_not_to_spec.rb

@@ -0,0 +1,24 @@
+# Copyright (C) 2012-2022 Zammad Foundation, https://zammad-foundation.org/
+
+require 'rails_helper'
+require_relative '../../../../.rubocop/cop/zammad/have_no_over_not_to'
+
+RSpec.describe RuboCop::Cop::Zammad::HaveNoOverNotTo, type: :rubocop do
+
+  it 'accepts .to have_no' do
+    expect_no_offenses("expect(page).to have_no_css('#elem')")
+  end
+
+  context 'with .not_to have' do
+    it 'registers an offense' do
+      expect_offense(<<~RUBY)
+        expect(page).not_to have_css('#elem')
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer `.to have_no_css` over `.not_to have_css`.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        expect(page).to have_no_css('#elem')
+      RUBY
+    end
+  end
+end

spec/support/rubocop.rb

@@ -0,0 +1,29 @@
+# Copyright (C) 2012-2022 Zammad Foundation, https://zammad-foundation.org/
+
+require 'rubocop/rspec/support'
+
+# https://github.com/rubocop/rubocop/tree/91e72f8bb4a5a646845e7915052f912d60a3d280/lib/rubocop/rspec/shared_contexts.rb:52
+RSpec.shared_context 'when checking custom RuboCop cops' do
+
+  include RuboCop::RSpec::ExpectOffense
+
+  let(:cop_options) { {} }
+  let(:cop_config) { {} }
+
+  let(:cur_cop_config) do
+    RuboCop::ConfigLoader
+      .default_configuration.for_cop(described_class)
+      .merge({
+               'Enabled'     => true, # in case it is 'pending'
+               'AutoCorrect' => true # in case defaults set it to false
+             })
+      .merge(cop_config)
+  end
+
+  let(:config) { ::RuboCop::Config.new({ described_class.cop_name => cur_cop_config }, "#{Rails.configuration.root}/.rubocop.yml") }
+  let(:cop) { described_class.new(config, cop_options) }
+end
+
+RSpec.configure do |config|
+  config.include_context 'when checking custom RuboCop cops', type: :rubocop
+end