Add ChefModernize/DefaultActionFromInitialize and ChefModernize/Resou…

…rceNameFromInitialize: (#348)

Migrating HWRPs into custom resources one DSL call at a time

Signed-off-by: Tim Smith <tsmith@chef.io>

config/cookstyle.yml

@@ -805,6 +805,24 @@ ChefModernize/PowerShellGuardInterpreter:
   Exclude:
     - '**/metadata.rb'
 
+ChefModernize/DefaultActionFromInitialize:
+  Description: The default actions can now be specified using the `default_action` helper instead of using the @action variable in the resource provider initialize method.
+  Enabled: true
+  VersionAdded: '5.10.0'
+  Include:
+    - '**/resources/*.rb'
+    - '**/providers/*.rb'
+    - '**/libraries/*.rb'
+
+ChefModernize/ResourceNameFromInitialize:
+  Description: The name of a resource can be set with the "resource_name" helper instead of using the initialize method.
+  Enabled: true
+  VersionAdded: '5.10.0'
+  Include:
+    - '**/resources/*.rb'
+    - '**/providers/*.rb'
+    - '**/libraries/*.rb'
+
 ###############################
 # Migrating to new patterns
 ###############################

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

@@ -0,0 +1,66 @@
+#
+# Copyright:: 2019, 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 ChefModernize
+        # The default actions can now be specified using the `default_action` helper instead of using the @action variable in the resource provider initialize method. In general we recommend against writing HWRPs, but if HWRPs are necessary you should utilize as much of the resource DSL as possible.
+        #
+        # @example
+        #
+        #   # bad
+        #   def initialize(*args)
+        #     super
+        #     @action = :create
+        #   end
+        #
+        #  # good
+        #  default_action :create
+
+        class DefaultActionFromInitialize < Cop
+          include RangeHelp
+
+          MSG = 'The default action of a resource can be set with the "default_action" helper instead of using the initialize method.'.freeze
+
+          def on_def(node)
+            return unless node.method_name == :initialize
+            return if node.body.nil? # nil body is an empty initialize method
+
+            node.body.each_node do |x|
+              if x.assignment? && !x.node_parts.empty? && x.node_parts.first == :@action
+                add_offense(x, location: :expression, message: MSG, severity: :refactor)
+              end
+            end
+          end
+
+          def_node_search :intialize_method, '(def :initialize ... )'
+
+          def autocorrect(node)
+            lambda do |corrector|
+              # insert the new default_action call above the initialize method
+              initialize_node = intialize_method(processed_source.ast).first
+              corrector.insert_before(initialize_node.source_range, "default_action #{node.asgn_rhs.source}\n\n")
+
+              # remove the variable from the initialize method
+              corrector.remove(range_with_surrounding_space(range: node.loc.expression, side: :left))
+            end
+          end
+        end
+      end
+    end
+  end
+end

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

@@ -0,0 +1,66 @@
+#
+# Copyright:: 2019, 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 ChefModernize
+        # The resource name can now be specified using the `resource_name` helper instead of using the @resource_name variable in the resource provider initialize method. In general we recommend against writing HWRPs, but if HWRPs are necessary you should utilize as much of the resource DSL as possible.
+        #
+        # @example
+        #
+        #   # bad
+        #   def initialize(*args)
+        #     super
+        #     @resource_name = :foo
+        #   end
+        #
+        #  # good
+        #  resource_name :create
+
+        class ResourceNameFromInitialize < Cop
+          include RangeHelp
+
+          MSG = 'The name of a resource can be set with the "resource_name" helper instead of using the initialize method.'.freeze
+
+          def on_def(node)
+            return unless node.method_name == :initialize
+            return if node.body.nil? # nil body is an empty initialize method
+
+            node.body.each_node do |x|
+              if x.assignment? && !x.node_parts.empty? && x.node_parts.first == :@resource_name
+                add_offense(x, location: :expression, message: MSG, severity: :refactor)
+              end
+            end
+          end
+
+          def_node_search :intialize_method, '(def :initialize ... )'
+
+          def autocorrect(node)
+            lambda do |corrector|
+              # insert the new resource_name call above the initialize method
+              initialize_node = intialize_method(processed_source.ast).first
+              corrector.insert_before(initialize_node.source_range, "resource_name #{node.asgn_rhs.source}\n\n")
+
+              # remove the variable from the initialize method
+              corrector.remove(range_with_surrounding_space(range: node.loc.expression, side: :left))
+            end
+          end
+        end
+      end
+    end
+  end
+end

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

@@ -0,0 +1,47 @@
+#
+# Copyright:: 2019, 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::ChefModernize::DefaultActionFromInitialize, :config do
+  subject(:cop) { described_class.new(config) }
+
+  it 'registers an offense with a HWRP specifies the default_action in the initializer' do
+    expect_offense(<<~RUBY)
+      def initialize(*args)
+        super
+        @action = :create
+        ^^^^^^^^^^^^^^^^^ The default action of a resource can be set with the "default_action" helper instead of using the initialize method.
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      default_action :create
+
+      def initialize(*args)
+        super
+      end
+    RUBY
+  end
+
+  it 'does not register an offense with an empty initialize method' do
+    expect_no_offenses(<<~RUBY)
+    def initialize(*args)
+    end
+    RUBY
+  end
+end

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

@@ -0,0 +1,47 @@
+#
+# Copyright:: 2019, 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::ChefModernize::ResourceNameFromInitialize, :config do
+  subject(:cop) { described_class.new(config) }
+
+  it 'registers an offense with a HWRP specifies the resource_name in the initializer' do
+    expect_offense(<<~RUBY)
+      def initialize(*args)
+        super
+        @resource_name = :foo
+        ^^^^^^^^^^^^^^^^^^^^^ The name of a resource can be set with the "resource_name" helper instead of using the initialize method.
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      resource_name :foo
+
+      def initialize(*args)
+        super
+      end
+    RUBY
+  end
+
+  it 'does not register an offense with an empty initialize method' do
+    expect_no_offenses(<<~RUBY)
+    def initialize(*args)
+    end
+    RUBY
+  end
+end