Merge pull request #889 from chef/env_helpers

Add new Chef/Modernize/UseChefLanguageEnvHelpers cop

.github/ISSUE_TEMPLATE/SUPPORT_QUESTION.md

@@ -5,7 +5,7 @@ about: If you have a question 💬, please check out our Slack!
 
 We use GitHub issues to track bugs and feature requests. If you need help please post to our Mailing List or join the Chef Community Slack.
 
-* Chef Community Slack at <http://community-slack.chef.io/.>
+* Chef Community Slack at <https://community-slack.chef.io/.>
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config/cookstyle.yml

@@ -1896,6 +1896,16 @@ Chef/Modernize/DependsOnOpensslCookbook:
   Include:
     - '**/metadata.rb'
 
+Chef/Modernize/UseChefLanguageEnvHelpers:
+  Description: Chef Infra Client 15.5 and later include a large number of new helpers in the Chef Infra Language to simplify checking the system configuration in recipes and resources. These should be used when possible over more complex attribute or ENV var comparisons.
+  StyleGuide: 'chef_modernize_usecheflanguageenvhelpers'
+  Enabled: true
+  VersionAdded: '7.21.0'
+  Include:
+    - '**/resources/*.rb'
+    - '**/providers/*.rb'
+    - '**/recipes/*.rb'
+
 ###############################
 # Chef/RedundantCode: Cleanup unnecessary code in your cookbooks regardless of Chef Infra Client release
 ###############################

lib/rubocop/cop/chef/modernize/use_chef_language_env_helpers.rb

@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+#
+# Copyright:: 2021, 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
+      module Modernize
+        # Chef Infra Client 15.5 and later include a large number of new helpers in the Chef Infra Language to simplify checking the system configuration in recipes and resources. These should be used when possible over more complex attribute or ENV var comparisons.
+        #
+        # @example
+        #
+        #   #### incorrect
+        #   ENV['CI']
+        #   ENV['TEST_KITCHEN']
+        #
+        #   #### correct
+        #   ci?
+        #   kitchen?
+        #
+        class UseChefLanguageEnvHelpers < Base
+          extend AutoCorrector
+
+          RESTRICT_ON_SEND = [:[]].freeze
+
+          def_node_matcher :env?, <<-PATTERN
+            (send
+              (const nil? :ENV) :[]
+              (str ${"TEST_KITCHEN" "CI"}))
+          PATTERN
+
+          def on_send(node)
+            env?(node) do |env_value|
+              # we don't handle .nil? checks yet so just skip them
+              next if node.parent.send_type? && node.parent.method_name == :nil?
+
+              case env_value
+              when 'CI'
+                add_offense(node, message: 'Chef Infra Client 15.5 and later include a helper `ci?` that should be used to see if the `CI` env var is set.', severity: :refactor) do |corrector|
+                  corrector.replace(node, 'ci?')
+                end
+              when 'TEST_KITCHEN'
+                add_offense(node, message: 'Chef Infra Client 15.5 and later include a helper `kitchen?` that should be used to see if the `TEST_KITCHEN` env var is set.', severity: :refactor) do |corrector|
+                  corrector.replace(node, 'kitchen?')
+                end
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/chef/modernize/use_chef_language_env_helpers_spec.rb

@@ -0,0 +1,69 @@
+# 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.
+#
+
+require 'spec_helper'
+
+describe RuboCop::Cop::Chef::Modernize::UseChefLanguageEnvHelpers, :config do
+  subject(:cop) { described_class.new(config) }
+
+  it "registers an offense when using ENV['CI'] in a cookbook" do
+    expect_offense(<<~RUBY)
+      if ENV['CI']
+         ^^^^^^^^^ Chef Infra Client 15.5 and later include a helper `ci?` that should be used to see if the `CI` env var is set.
+        foo
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      if ci?
+        foo
+      end
+    RUBY
+  end
+
+  it "registers an offense when using ENV['TEST_KITCHEN'] in a cookbook" do
+    expect_offense(<<~RUBY)
+      if ENV['TEST_KITCHEN']
+         ^^^^^^^^^^^^^^^^^^^ Chef Infra Client 15.5 and later include a helper `kitchen?` that should be used to see if the `TEST_KITCHEN` env var is set.
+        foo
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      if kitchen?
+        foo
+      end
+    RUBY
+  end
+
+  it 'does not alert when checking if the env var is nil' do
+    expect_no_offenses(<<~RUBY)
+      unless ENV['TEST_KITCHEN'].nil?
+        foo
+      end
+    RUBY
+  end
+
+  it 'does not alert when checking any old env var' do
+    expect_no_offenses(<<~RUBY)
+      if ENV['NOT_TEST_KITCHEN']
+        foo
+      end
+    RUBY
+  end
+end