1 files changed, 27 insertions, 21 deletions

diff --git a/actionpack/lib/action_controller/renderer.rb b/actionpack/lib/action_controller/renderer.rb
index 2775a24e56..49c5b782f0 100644
--- a/actionpack/lib/action_controller/renderer.rb
+++ b/actionpack/lib/action_controller/renderer.rb
@@ -1,11 +1,13 @@
-require 'active_support/core_ext/hash/keys'
+# frozen_string_literal: true
+
+require "active_support/core_ext/hash/keys"
 
 module ActionController
-  # ActionController::Renderer allows to render arbitrary templates
+  # ActionController::Renderer allows you to render arbitrary templates
   # without requirement of being in controller actions.
   #
   # You get a concrete renderer class by invoking ActionController::Base#renderer.
-  # For example,
+  # For example:
   #
   #   ApplicationController.renderer
   #
@@ -13,12 +15,12 @@ module ActionController
   #
   #   ApplicationController.renderer.render template: '...'
   #
-  # You can use a shortcut on controller to replace previous example with:
+  # You can use this shortcut in a controller, instead of the previous example:
   #
   #   ApplicationController.render template: '...'
   #
-  # #render method allows you to use any options as when rendering in controller.
-  # For example,
+  # #render allows you to use the same options that you can use when rendering in a controller.
+  # For example:
   #
   #   FooController.render :action, locals: { ... }, assigns: { ... }
   #
@@ -37,11 +39,11 @@ module ActionController
     attr_reader :defaults, :controller
 
     DEFAULTS = {
-      http_host: 'example.org',
+      http_host: "example.org",
       https: false,
-      method: 'get',
-      script_name: '',
-      input: ''
+      method: "get",
+      script_name: "",
+      input: ""
     }.freeze
 
     # Create a new renderer instance for a specific controller class.
@@ -56,11 +58,12 @@ module ActionController
 
     # Create a new renderer for the same controller but with new defaults.
     def with_defaults(defaults)
-      self.class.new controller, env, self.defaults.merge(defaults)
+      self.class.new controller, @env, self.defaults.merge(defaults)
     end
 
     # Accepts a custom Rack environment to render templates in.
-    # It will be merged with ActionController::Renderer.defaults
+    # It will be merged with the default Rack environment defined by
+    # +ActionController::Renderer::DEFAULTS+.
     def initialize(controller, env, defaults)
       @controller = controller
       @defaults = defaults
@@ -69,7 +72,7 @@ module ActionController
 
     # Render templates with any options from ActionController::Base#render_to_string.
     def render(*args)
-      raise 'missing controller' unless controller
+      raise "missing controller" unless controller
 
       request = ActionDispatch::Request.new @env
       request.routes = controller._routes
@@ -83,26 +86,29 @@ module ActionController
     private
       def normalize_keys(env)
         new_env = {}
-        env.each_pair { |k,v| new_env[rack_key_for(k)] = rack_value_for(k, v) }
+        env.each_pair { |k, v| new_env[rack_key_for(k)] = rack_value_for(k, v) }
+        new_env["rack.url_scheme"] = new_env["HTTPS"] == "on" ? "https" : "http"
         new_env
       end
 
       RACK_KEY_TRANSLATION = {
-        http_host:   'HTTP_HOST',
-        https:       'HTTPS',
-        method:      'REQUEST_METHOD',
-        script_name: 'SCRIPT_NAME',
-        input:       'rack.input'
+        http_host:   "HTTP_HOST",
+        https:       "HTTPS",
+        method:      "REQUEST_METHOD",
+        script_name: "SCRIPT_NAME",
+        input:       "rack.input"
       }
 
       IDENTITY = ->(_) { _ }
 
       RACK_VALUE_TRANSLATION = {
-        https: ->(v) { v ? 'on' : 'off' },
+        https: ->(v) { v ? "on" : "off" },
         method: ->(v) { v.upcase },
       }
 
-      def rack_key_for(key); RACK_KEY_TRANSLATION[key]; end
+      def rack_key_for(key)
+        RACK_KEY_TRANSLATION.fetch(key, key.to_s)
+      end
 
       def rack_value_for(key, value)
         RACK_VALUE_TRANSLATION.fetch(key, IDENTITY).call value