1 files changed, 19 insertions, 4 deletions
diff --git a/actionpack/test/dispatch/system_testing/server_test.rb b/actionpack/test/dispatch/system_testing/server_test.rb
index 10412d6367..95e411faf4 100644
--- a/actionpack/test/dispatch/system_testing/server_test.rb
+++ b/actionpack/test/dispatch/system_testing/server_test.rb
@@ -1,17 +1,32 @@
+# frozen_string_literal: true
+
 require "abstract_unit"
 require "capybara/dsl"
 require "action_dispatch/system_testing/server"
 
 class ServerTest < ActiveSupport::TestCase
   setup do
+    @old_capybara_server = Capybara.server
+  end
+
+  test "port is always included" do
     ActionDispatch::SystemTesting::Server.new.run
+    assert Capybara.always_include_port, "expected Capybara.always_include_port to be true"
   end
 
-  test "initializing the server port" do
-    assert_includes Capybara.servers, :rails_puma
+  test "server is changed from `default` to `puma`" do
+    Capybara.server = :default
+    ActionDispatch::SystemTesting::Server.new.run
+    refute_equal Capybara.server, Capybara.servers[:default]
   end
 
-  test "port is always included" do
-    assert Capybara.always_include_port, "expected Capybara.always_include_port to be true"
+  test "server is not changed to `puma` when is different than default" do
+    Capybara.server = :webrick
+    ActionDispatch::SystemTesting::Server.new.run
+    assert_equal Capybara.server, Capybara.servers[:webrick]
+  end
+
+  teardown do
+    Capybara.server = @old_capybara_server
   end
 end