diff --git a/lib/capybara/selector/regexp_disassembler.rb b/lib/capybara/selector/regexp_disassembler.rb
index 5de51a52..e9ef4932 100644
--- a/lib/capybara/selector/regexp_disassembler.rb
+++ b/lib/capybara/selector/regexp_disassembler.rb
@@ -11,7 +11,7 @@ module Capybara
       end
 
       def alternated_substrings
-        @options ||= begin
+        @alternated_substrings ||= begin
           process(alternation: true)
         end
       end
@@ -26,12 +26,11 @@ module Capybara
 
       def process(alternation:)
         strs = extract_strings(Regexp::Parser.parse(@regexp), [''], alternation: alternation)
-        strs = collapse(combine(strs).map &:flatten)
+        strs = collapse(combine(strs).map(&:flatten))
         strs.each { |str| str.map!(&:upcase) } if @regexp.casefold?
         strs
       end
 
-
       def min_repeat(exp)
         exp.quantifier&.min || 1
       end
@@ -44,7 +43,6 @@ module Capybara
         min_repeat(exp).zero?
       end
 
-
       def combine(strs)
         suffixes = [[]]
         strs.reverse_each do |str|
@@ -65,7 +63,7 @@ module Capybara
 
       def collapse(strs)
         strs.map do |substrings|
-          substrings.slice_before { |str| str.empty? }.map(&:join).reject(&:empty?).uniq
+          substrings.slice_before(&:empty?).map(&:join).reject(&:empty?).uniq
         end
       end
 
@@ -77,12 +75,7 @@ module Capybara
           end
 
           if %i[meta].include?(exp.type) && !exp.terminal? && alternation
-            alternatives = exp.alternatives.map { |sub_exp| extract_strings(sub_exp, [], alternation: true) }
-            if alternatives.all? { |alt| alt.any? { |a| !a.empty? } }
-              strings.push(Set.new(alternatives))
-            else
-              strings.push('')
-            end
+            strings.push(alternative_strings(exp))
             next
           end
 
@@ -94,9 +87,9 @@ module Capybara
           if exp.terminal?
             case exp.type
             when :literal
-              strings.push (exp.text * min_repeat(exp))
+              strings.push(exp.text * min_repeat(exp))
             when :escape
-              strings.push (exp.char * min_repeat(exp))
+              strings.push(exp.char * min_repeat(exp))
             else
               strings.push('')
             end
@@ -107,6 +100,15 @@ module Capybara
         end
         strings
       end
+
+      def alternative_strings(expression)
+        alternatives = expression.alternatives.map { |sub_exp| extract_strings(sub_exp, [], alternation: true) }
+        if alternatives.all? { |alt| alt.any? { |a| !a.empty? } }
+          Set.new(alternatives)
+        else
+          strings.push('')
+        end
+      end
     end
   end
 end
diff --git a/spec/regexp_dissassembler_spec.rb b/spec/regexp_dissassembler_spec.rb
index cc8a113f..58e8590e 100644
--- a/spec/regexp_dissassembler_spec.rb
+++ b/spec/regexp_dissassembler_spec.rb
@@ -113,16 +113,16 @@ RSpec.describe Capybara::Selector::RegexpDisassembler do
 
   it 'handles alternation for #options' do
     verify_alternated_strings(
-      /abc|def/ => [%w[abc],%w[def]],
-      /ab(?:c|d)/ => [%w[abc],%w[abd]],
-      /ab(c|d|e)fg/ => [%w[abcfg],%w[abdfg],%w[abefg]],
+      /abc|def/ => [%w[abc], %w[def]],
+      /ab(?:c|d)/ => [%w[abc], %w[abd]],
+      /ab(c|d|e)fg/ => [%w[abcfg], %w[abdfg], %w[abefg]],
       /ab?(c|d)fg/ => [%w[a cfg], %w[a dfg]],
       /ab(c|d)ef/ => [%w[abcef], %w[abdef]],
       /ab(cd?|ef)g/ => [%w[abc g], %w[abefg]],
       /ab(cd|ef*)g/ => [%w[abcdg], %w[abe g]],
       /ab|cd*/ => [%w[ab], %w[c]],
-      /cd(?:ef|gh)|xyz/ => [%w[cdef],%w[cdgh],%w[xyz]],
-      /(cd(?:ef|gh)|xyz)/ => [%w[cdef],%w[cdgh],%w[xyz]],
+      /cd(?:ef|gh)|xyz/ => [%w[cdef], %w[cdgh], %w[xyz]],
+      /(cd(?:ef|gh)|xyz)/ => [%w[cdef], %w[cdgh], %w[xyz]],
       /cd(ef|gh)+/ => [%w[cdef], %w[cdgh]],
       /cd(ef|gh)?/ => [%w[cd]],
       /cd(ef|gh)?ij/ => [%w[cd ij]],