1 files changed, 100 insertions, 0 deletions
diff --git a/actionview/lib/action_view/path_set.rb b/actionview/lib/action_view/path_set.rb
new file mode 100644
index 0000000000..691b53e2da
--- /dev/null
+++ b/actionview/lib/action_view/path_set.rb
@@ -0,0 +1,100 @@
+# frozen_string_literal: true
+
+module ActionView #:nodoc:
+  # = Action View PathSet
+  #
+  # This class is used to store and access paths in Action View. A number of
+  # operations are defined so that you can search among the paths in this
+  # set and also perform operations on other +PathSet+ objects.
+  #
+  # A +LookupContext+ will use a +PathSet+ to store the paths in its context.
+  class PathSet #:nodoc:
+    include Enumerable
+
+    attr_reader :paths
+
+    delegate :[], :include?, :pop, :size, :each, to: :paths
+
+    def initialize(paths = [])
+      @paths = typecast paths
+    end
+
+    def initialize_copy(other)
+      @paths = other.paths.dup
+      self
+    end
+
+    def to_ary
+      paths.dup
+    end
+
+    def compact
+      PathSet.new paths.compact
+    end
+
+    def +(array)
+      PathSet.new(paths + array)
+    end
+
+    %w(<< concat push insert unshift).each do |method|
+      class_eval <<-METHOD, __FILE__, __LINE__ + 1
+        def #{method}(*args)
+          paths.#{method}(*typecast(args))
+        end
+      METHOD
+    end
+
+    def find(*args)
+      find_all(*args).first || raise(MissingTemplate.new(self, *args))
+    end
+
+    def find_file(path, prefixes = [], *args)
+      _find_all(path, prefixes, args, true).first || raise(MissingTemplate.new(self, path, prefixes, *args))
+    end
+
+    def find_all(path, prefixes = [], *args)
+      _find_all path, prefixes, args, false
+    end
+
+    def exists?(path, prefixes, *args)
+      find_all(path, prefixes, *args).any?
+    end
+
+    def find_all_with_query(query) # :nodoc:
+      paths.each do |resolver|
+        templates = resolver.find_all_with_query(query)
+        return templates unless templates.empty?
+      end
+
+      []
+    end
+
+    private
+
+      def _find_all(path, prefixes, args, outside_app)
+        prefixes = [prefixes] if String === prefixes
+        prefixes.each do |prefix|
+          paths.each do |resolver|
+            if outside_app
+              templates = resolver.find_all_anywhere(path, prefix, *args)
+            else
+              templates = resolver.find_all(path, prefix, *args)
+            end
+            return templates unless templates.empty?
+          end
+        end
+        []
+      end
+
+      def typecast(paths)
+        paths.map do |path|
+          case path
+          when Pathname, String
+            OptimizedFileSystemResolver.new path.to_s
+          else
+            path
+          end
+        end
+      end
+  end
+end