1 files changed, 16 insertions, 14 deletions
diff --git a/actionpack/test/controller/new_base/bare_metal_test.rb b/actionpack/test/controller/new_base/bare_metal_test.rb
index ee3c498b1c..b049022a06 100644
--- a/actionpack/test/controller/new_base/bare_metal_test.rb
+++ b/actionpack/test/controller/new_base/bare_metal_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "abstract_unit"
 
 module BareMetalTest
@@ -11,7 +13,7 @@ module BareMetalTest
     test "response body is a Rack-compatible response" do
       status, headers, body = BareController.action(:index).call(Rack::MockRequest.env_for("/"))
       assert_equal 200, status
-      string = ""
+      string = "".dup
 
       body.each do |part|
         assert part.is_a?(String), "Each part of the body must be a String"
@@ -52,7 +54,7 @@ module BareMetalTest
       controller.set_request!(ActionDispatch::Request.empty)
       controller.set_response!(BareController.make_response!(controller.request))
       controller.index
-      assert_equal nil, controller.response_body
+      assert_nil controller.response_body
     end
   end
 
@@ -102,38 +104,38 @@ module BareMetalTest
 
     test "head :continue (100) does not return a content-type header" do
       headers = HeadController.action(:continue).call(Rack::MockRequest.env_for("/")).second
-      assert_nil headers['Content-Type']
-      assert_nil headers['Content-Length']
+      assert_nil headers["Content-Type"]
+      assert_nil headers["Content-Length"]
     end
 
     test "head :switching_protocols (101) does not return a content-type header" do
       headers = HeadController.action(:switching_protocols).call(Rack::MockRequest.env_for("/")).second
-      assert_nil headers['Content-Type']
-      assert_nil headers['Content-Length']
+      assert_nil headers["Content-Type"]
+      assert_nil headers["Content-Length"]
     end
 
     test "head :processing (102) does not return a content-type header" do
       headers = HeadController.action(:processing).call(Rack::MockRequest.env_for("/")).second
-      assert_nil headers['Content-Type']
-      assert_nil headers['Content-Length']
+      assert_nil headers["Content-Type"]
+      assert_nil headers["Content-Length"]
     end
 
     test "head :no_content (204) does not return a content-type header" do
       headers = HeadController.action(:no_content).call(Rack::MockRequest.env_for("/")).second
-      assert_nil headers['Content-Type']
-      assert_nil headers['Content-Length']
+      assert_nil headers["Content-Type"]
+      assert_nil headers["Content-Length"]
     end
 
     test "head :reset_content (205) does not return a content-type header" do
       headers = HeadController.action(:reset_content).call(Rack::MockRequest.env_for("/")).second
-      assert_nil headers['Content-Type']
-      assert_nil headers['Content-Length']
+      assert_nil headers["Content-Type"]
+      assert_nil headers["Content-Length"]
     end
 
     test "head :not_modified (304) does not return a content-type header" do
       headers = HeadController.action(:not_modified).call(Rack::MockRequest.env_for("/")).second
-      assert_nil headers['Content-Type']
-      assert_nil headers['Content-Length']
+      assert_nil headers["Content-Type"]
+      assert_nil headers["Content-Length"]
     end
 
     test "head :no_content (204) does not return any content" do