Allow .test by default in development (#51087)

This ensures out-of-the-box compatibility with puma-dev

actionpack/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Add ".test" as a default allowed host in development to ensure smooth golden-path setup with puma.dev.
+
+    *DHH*
+
 *   Add `allow_browser` to set minimum browser versions for the application.
 
     A browser that's blocked will by default be served the file in `public/426.html` with a HTTP status code of "426 Upgrade Required".

actionpack/lib/action_dispatch/middleware/host_authorization.rb

@@ -20,7 +20,7 @@ module ActionDispatch
   # info if `config.consider_all_requests_local` is set to true, otherwise the
   # body is empty.
   class HostAuthorization
-    ALLOWED_HOSTS_IN_DEVELOPMENT = [".localhost", IPAddr.new("0.0.0.0/0"), IPAddr.new("::/0")]
+    ALLOWED_HOSTS_IN_DEVELOPMENT = [".localhost", ".test", IPAddr.new("0.0.0.0/0"), IPAddr.new("::/0")]
     PORT_REGEX = /(?::\d+)/ # :nodoc:
     SUBDOMAIN_REGEX = /(?:[a-z0-9-]+\.)/i # :nodoc:
     IPV4_HOSTNAME = /(?<host>\d+\.\d+\.\d+\.\d+)#{PORT_REGEX}?/ # :nodoc:

railties/test/application/configuration_test.rb

@@ -3997,6 +3997,11 @@ class Post < ActiveRecord::Base
       assert_includes Rails.application.config.hosts, ".localhost"
     end
 
+    test "hosts include .test in development" do
+      app "development"
+      assert_includes Rails.application.config.hosts, ".test"
+    end
+
     test "hosts reads multiple values from RAILS_DEVELOPMENT_HOSTS" do
       host = "agoodhost.com"
       another_host = "bananapants.com"