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diff --git a/actionpack/lib/action_dispatch/testing/assertions/response.rb b/actionpack/lib/action_dispatch/testing/assertions/response.rb
new file mode 100644
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+++ b/actionpack/lib/action_dispatch/testing/assertions/response.rb
@@ -0,0 +1,106 @@
+# frozen_string_literal: true
+
+module ActionDispatch
+  module Assertions
+    # A small suite of assertions that test responses from \Rails applications.
+    module ResponseAssertions
+      RESPONSE_PREDICATES = { # :nodoc:
+        success:  :successful?,
+        missing:  :not_found?,
+        redirect: :redirection?,
+        error:    :server_error?,
+      }
+
+      # Asserts that the response is one of the following types:
+      #
+      # * <tt>:success</tt>   - Status code was in the 200-299 range
+      # * <tt>:redirect</tt>  - Status code was in the 300-399 range
+      # * <tt>:missing</tt>   - Status code was 404
+      # * <tt>:error</tt>     - Status code was in the 500-599 range
+      #
+      # You can also pass an explicit status number like <tt>assert_response(501)</tt>
+      # or its symbolic equivalent <tt>assert_response(:not_implemented)</tt>.
+      # See Rack::Utils::SYMBOL_TO_STATUS_CODE for a full list.
+      #
+      #   # Asserts that the response was a redirection
+      #   assert_response :redirect
+      #
+      #   # Asserts that the response code was status code 401 (unauthorized)
+      #   assert_response 401
+      def assert_response(type, message = nil)
+        message ||= generate_response_message(type)
+
+        if RESPONSE_PREDICATES.keys.include?(type)
+          assert @response.send(RESPONSE_PREDICATES[type]), message
+        else
+          assert_equal AssertionResponse.new(type).code, @response.response_code, message
+        end
+      end
+
+      # Asserts that the redirection options passed in match those of the redirect called in the latest action.
+      # This match can be partial, such that <tt>assert_redirected_to(controller: "weblog")</tt> will also
+      # match the redirection of <tt>redirect_to(controller: "weblog", action: "show")</tt> and so on.
+      #
+      #   # Asserts that the redirection was to the "index" action on the WeblogController
+      #   assert_redirected_to controller: "weblog", action: "index"
+      #
+      #   # Asserts that the redirection was to the named route login_url
+      #   assert_redirected_to login_url
+      #
+      #   # Asserts that the redirection was to the URL for @customer
+      #   assert_redirected_to @customer
+      #
+      #   # Asserts that the redirection matches the regular expression
+      #   assert_redirected_to %r(\Ahttp://example.org)
+      def assert_redirected_to(options = {}, message = nil)
+        assert_response(:redirect, message)
+        return true if options === @response.location
+
+        redirect_is       = normalize_argument_to_redirection(@response.location)
+        redirect_expected = normalize_argument_to_redirection(options)
+
+        message ||= "Expected response to be a redirect to <#{redirect_expected}> but was a redirect to <#{redirect_is}>"
+        assert_operator redirect_expected, :===, redirect_is, message
+      end
+
+      private
+        # Proxy to to_param if the object will respond to it.
+        def parameterize(value)
+          value.respond_to?(:to_param) ? value.to_param : value
+        end
+
+        def normalize_argument_to_redirection(fragment)
+          if Regexp === fragment
+            fragment
+          else
+            handle = @controller || ActionController::Redirecting
+            handle._compute_redirect_to_location(@request, fragment)
+          end
+        end
+
+        def generate_response_message(expected, actual = @response.response_code)
+          (+"Expected response to be a <#{code_with_name(expected)}>,"\
+          " but was a <#{code_with_name(actual)}>").concat(location_if_redirected).concat(response_body_if_short)
+        end
+
+        def response_body_if_short
+          return "" if @response.body.size > 500
+          "\nResponse body: #{@response.body}"
+        end
+
+        def location_if_redirected
+          return "" unless @response.redirection? && @response.location.present?
+          location = normalize_argument_to_redirection(@response.location)
+          " redirect to <#{location}>"
+        end
+
+        def code_with_name(code_or_name)
+          if RESPONSE_PREDICATES.values.include?("#{code_or_name}?".to_sym)
+            code_or_name = RESPONSE_PREDICATES.invert["#{code_or_name}?".to_sym]
+          end
+
+          AssertionResponse.new(code_or_name).code_and_name
+        end
+    end
+  end
+end