[Fix rubocop#4199] Fix incorrect auto correction in `Style/SymbolArra…

…y` cop

See rubocop#4199

If `PreferredDelimiters` option is specified, `Style/SymbolArray` and `Style/WordArray` cops auto correct to not expected code.
The option is ignored.

For example

```ruby
 # PreferredDelimiters is []

 # Before
 [:a, :b, :c]
 ['a', 'b', 'c']

 # Corrected
 %i(a b c) # Not %i[]
 %w(a b c) # Not %w[]
```

This change fixes the problem.

CHANGELOG.md

@@ -10,6 +10,7 @@
 * [#4172](https://github.com/bbatsov/rubocop/pull/4172): Fix false positives in `Style/MixinGrouping` cop. ([@drenmi][])
 * [#4185](https://github.com/bbatsov/rubocop/pull/4185): Make `Lint/NestedMethodDefinition` aware of `#*_exec` class of methods. ([@drenmi][])
 * [#4197](https://github.com/bbatsov/rubocop/pull/4197): Fix false positive in `Style/RedundantSelf` cop with parallel assignment. ([@drenmi][])
+* [#4199](https://github.com/bbatsov/rubocop/issues/4199): Fix incorrect auto correction in `Style/SymbolArray` and `Style/WordArray` cop. ([@pocke][])
 
 ## 0.48.0 (2017-03-26)
 

lib/rubocop/cop/mixin/percent_literal.rb

@@ -4,6 +4,8 @@ module RuboCop
   module Cop
     # Common functionality for handling percent literals.
     module PercentLiteral
+      PERCENT_LITERAL_TYPES = %w(% %i %I %q %Q %r %s %w %W %x).freeze
+
       private
 
       def percent_literal?(node)
@@ -35,25 +37,64 @@ def correct_percent(node, char)
         words = node.children
         escape = words.any? { |w| needs_escaping?(w.children[0]) }
         char = char.upcase if escape
-        contents = autocorrect_words(words, escape, node.loc.line)
+        delimiters = preferred_delimiters_for("%#{char}")
+        contents = autocorrect_words(words, escape, node.loc.line, delimiters)
 
         lambda do |corrector|
-          corrector.replace(node.source_range, "%#{char}(#{contents})")
+          corrector.replace(
+            node.source_range,
+            "%#{char}#{delimiters[0]}#{contents}#{delimiters[1]}"
+          )
         end
       end
 
-      def autocorrect_words(word_nodes, escape, base_line_number)
+      def autocorrect_words(word_nodes, escape, base_line_number, delimiters)
         previous_node_line_number = base_line_number
         word_nodes.map do |node|
           number_of_line_breaks = node.loc.line - previous_node_line_number
           line_breaks = "\n" * number_of_line_breaks
           previous_node_line_number = node.loc.line
           content = node.children.first.to_s
           content = escape ? escape_string(content) : content
-          content.gsub!(/\)/, '\\)')
+          delimiters.each do |delimiter|
+            content.gsub!(delimiter, "\\#{delimiter}")
+          end
           line_breaks + content
         end.join(' ')
       end
+
+      def ensure_valid_preferred_delimiters
+        invalid = preferred_delimiters_config.keys -
+                  (PERCENT_LITERAL_TYPES + %w(default))
+        return if invalid.empty?
+
+        raise ArgumentError,
+              "Invalid preferred delimiter config key: #{invalid.join(', ')}"
+      end
+
+      def preferred_delimiters
+        @preferred_delimiters ||=
+          begin
+            ensure_valid_preferred_delimiters
+
+            if preferred_delimiters_config.key?('default')
+              Hash[PERCENT_LITERAL_TYPES.map do |type|
+                [type, preferred_delimiters_config[type] ||
+                  preferred_delimiters_config['default']]
+              end]
+            else
+              preferred_delimiters_config
+            end
+          end
+      end
+
+      def preferred_delimiters_config
+        @config.for_cop('Style/PercentLiteralDelimiters')['PreferredDelimiters']
+      end
+
+      def preferred_delimiters_for(type)
+        preferred_delimiters[type].split(//)
+      end
     end
   end
 end

lib/rubocop/cop/style/percent_literal_delimiters.rb

@@ -26,8 +26,6 @@ module Style
       class PercentLiteralDelimiters < Cop
         include PercentLiteral
 
-        PERCENT_LITERAL_TYPES = %w(% %i %I %q %Q %r %s %w %W %x).freeze
-
         def on_array(node)
           process(node, '%w', '%W', '%i', '%I')
         end
@@ -78,35 +76,6 @@ def on_percent_literal(node)
           add_offense(node, :expression)
         end
 
-        def preferred_delimiters
-          @preferred_delimiters ||=
-            begin
-              ensure_valid_preferred_delimiters
-
-              if cop_config['PreferredDelimiters'].key?('default')
-                Hash[PERCENT_LITERAL_TYPES.map do |type|
-                  [type, cop_config['PreferredDelimiters'][type] ||
-                    cop_config['PreferredDelimiters']['default']]
-                end]
-              else
-                cop_config['PreferredDelimiters']
-              end
-            end
-        end
-
-        def ensure_valid_preferred_delimiters
-          invalid = cop_config['PreferredDelimiters'].keys -
-                    (PERCENT_LITERAL_TYPES + %w(default))
-          return if invalid.empty?
-
-          raise ArgumentError,
-                "Invalid preferred delimiter config key: #{invalid.join(', ')}"
-        end
-
-        def preferred_delimiters_for(type)
-          preferred_delimiters[type].split(//)
-        end
-
         def uses_preferred_delimiter?(node, type)
           preferred_delimiters_for(type)[0] == begin_source(node)[-1]
         end

spec/rubocop/cop/style/symbol_array_spec.rb

@@ -3,6 +3,16 @@
 describe RuboCop::Cop::Style::SymbolArray, :config do
   subject(:cop) { described_class.new(config) }
 
+  let(:other_cops) do
+    {
+      'Style/PercentLiteralDelimiters' => {
+        'PreferredDelimiters' => {
+          'default' => '()'
+        }
+      }
+    }
+  end
+
   context 'when EnforcedStyle is percent' do
     let(:cop_config) { { 'EnforcedStyle' => 'percent' } }
 
@@ -28,8 +38,9 @@
     end
 
     it "doesn't break when a symbol contains )" do
-      new_source = autocorrect_source(cop, '[:one, :")", :three]')
-      expect(new_source).to eq('%i(one \\) three)')
+      source = '[:one, :")", :three, :"(", :"]", :"["]'
+      new_source = autocorrect_source(cop, source)
+      expect(new_source).to eq('%i(one \\) three \\( ] [)')
     end
 
     it 'does not register an offense for array with non-syms' do
@@ -58,6 +69,24 @@
         expect(cop.offenses).to be_empty
       end
     end
+
+    context 'when PreferredDelimiters is specified' do
+      let(:other_cops) do
+        {
+          'Style/PercentLiteralDelimiters' => {
+            'PreferredDelimiters' => {
+              'default' => '[]'
+            }
+          }
+        }
+      end
+
+      it 'autocorrects an array with delimiters' do
+        source = '[:one, :")", :three, :"(", :"]", :"["]'
+        new_source = autocorrect_source(cop, source)
+        expect(new_source).to eq('%i[one ) three ( \\] \\[]')
+      end
+    end
   end
 
   context 'when EnforcedStyle is array' do

spec/rubocop/cop/style/word_array_spec.rb

@@ -8,6 +8,16 @@
     described_class.largest_brackets = -Float::INFINITY
   end
 
+  let(:other_cops) do
+    {
+      'Style/PercentLiteralDelimiters' => {
+        'PreferredDelimiters' => {
+          'default' => '()'
+        }
+      }
+    }
+  end
+
   context 'when EnforcedStyle is percent' do
     let(:cop_config) do
       { 'MinSize' => 0,
@@ -255,8 +265,25 @@
     end
 
     it "doesn't break when words contain delimiters" do
-      new_source = autocorrect_source(cop, "[')', ']']")
-      expect(new_source).to eq('%w(\\) ])')
+      new_source = autocorrect_source(cop, "[')', ']', '(']")
+      expect(new_source).to eq('%w(\\) ] \\()')
+    end
+
+    context 'when PreferredDelimiters is specified' do
+      let(:other_cops) do
+        {
+          'Style/PercentLiteralDelimiters' => {
+            'PreferredDelimiters' => {
+              'default' => '[]'
+            }
+          }
+        }
+      end
+
+      it 'autocorrects an array with delimiters' do
+        new_source = autocorrect_source(cop, "[')', ']', '(', '[']")
+        expect(new_source).to eq('%w[) \\] ( \\[]')
+      end
     end
   end
 end