1 files changed, 15 insertions, 6 deletions
diff --git a/actionpack/lib/action_dispatch/journey/path/pattern.rb b/actionpack/lib/action_dispatch/journey/path/pattern.rb
index 5ee8810066..537f479ee5 100644
--- a/actionpack/lib/action_dispatch/journey/path/pattern.rb
+++ b/actionpack/lib/action_dispatch/journey/path/pattern.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 module ActionDispatch
   module Journey # :nodoc:
     module Path # :nodoc:
       class Pattern # :nodoc:
         attr_reader :spec, :requirements, :anchored
 
-        def self.from_string string
+        def self.from_string(string)
           build(string, {}, "/.?", true)
         end
 
@@ -31,6 +33,13 @@ module ActionDispatch
           Visitors::FormatBuilder.new.accept(spec)
         end
 
+        def eager_load!
+          required_names
+          offsets
+          to_regexp
+          nil
+        end
+
         def ast
           @spec.find_all(&:symbol?).each do |node|
             re = @requirements[node.to_sym]
@@ -81,7 +90,7 @@ module ActionDispatch
             return @separator_re unless @matchers.key?(node)
 
             re = @matchers[node]
-            "(#{re})"
+            "(#{Regexp.union(re)})"
           end
 
           def visit_GROUP(node)
@@ -98,7 +107,7 @@ module ActionDispatch
           end
 
           def visit_STAR(node)
-            re = @matchers[node.left.to_sym] || '.+'
+            re = @matchers[node.left.to_sym] || ".+"
             "(#{re})"
           end
 
@@ -124,7 +133,7 @@ module ActionDispatch
           end
 
           def captures
-            (length - 1).times.map { |i| self[i + 1] }
+            Array.new(length - 1) { |i| self[i + 1] }
           end
 
           def [](x)
@@ -174,8 +183,8 @@ module ActionDispatch
               node = node.to_sym
 
               if @requirements.key?(node)
-                re = /#{@requirements[node]}|/
-                @offsets.push((re.match('').length - 1) + @offsets.last)
+                re = /#{Regexp.union(@requirements[node])}|/
+                @offsets.push((re.match("").length - 1) + @offsets.last)
               else
                 @offsets << @offsets.last
               end