Add ChefCorrectness/InvalidDefaultAction cop

config/cookstyle.yml

@@ -454,6 +454,15 @@ ChefCorrectness/InvalidPlatformInCase:
     - '**/metadata.rb'
     - '**/Berksfile'
 
+ChefCorrectness/InvalidDefaultAction:
+  Description: Default actions in resources should be a symbol or an array of symbols.
+  StyleGuide: '#chefcorrectnessinvaliddefaultaction'
+  Enabled: true
+  VersionAdded: '6.13.0'
+  Include:
+    - '**/libraries/*.rb'
+    - '**/resources/*.rb'
+
 ###############################
 # ChefSharing: Issues that prevent sharing code with other teams or with the Chef community in general
 ###############################

lib/rubocop/cop/chef/correctness/invalid_default_action.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+#
+# Copyright:: 2020, Chef Software Inc.
+# Author:: Tim Smith (<tsmith@chef.io>)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+module RuboCop
+  module Cop
+    module Chef
+      # Default actions in resources should be symbols or an array of symbols.
+      #
+      # @example
+      #
+      #   # bad
+      #   default_action 'create'
+      #
+      #   # good
+      #   default_action :create
+      #
+      module ChefCorrectness
+        class InvalidDefaultAction < Cop
+          MSG = 'Default actions in resources should be symbols or an array of symbols.'
+
+          def_node_matcher :default_action?, '(send nil? :default_action $_)'
+
+          def on_send(node)
+            default_action?(node) do |match|
+              return if %i(send sym array).include?(match.type)
+              add_offense(node, location: :expression, message: MSG, severity: :refactor)
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/chef/correctness/invalid_default_action_spec.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+#
+# Copyright:: Copyright 2020, Chef Software Inc.
+# Author:: Tim Smith (<tsmith@chef.io>)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'spec_helper'
+
+describe RuboCop::Cop::Chef::ChefCorrectness::InvalidDefaultAction do
+  subject(:cop) { described_class.new }
+
+  it 'registers an offense when default action is a string' do
+    expect_offense(<<~RUBY)
+      default_action 'create'
+      ^^^^^^^^^^^^^^^^^^^^^^^ Default actions in resources should be symbols or an array of symbols.
+    RUBY
+  end
+
+  it 'does not register an offense with a symbol' do
+    expect_no_offenses('default_action :create')
+  end
+
+  it 'does not register an offense with a variable' do
+    expect_no_offenses('default_action foo')
+  end
+
+  it 'does not register an offense with an array of symbols' do
+    expect_no_offenses('default_action [:create, :enable]')
+  end
+end