Implement CurrentAttributes#set in terms of Object#with

`CurrentAttributes` supports block-scoped overrides for its attributes
through the `#set` method. The introduction of [CurrentAttributes#set][]
predates the introduction of [Object#with][] by 6 years.

This commit changes the implementation of `#set` to delegate to `#with`.
Through that delegation, the private `#assign_attributes` and
`#compute_attributes` methods are no longer necessary.

[CurrentAttributes#set]: https://github.com/rails/rails/blame/2d6b02bad6b02bf1d26c26461406bda710181244/activesupport/lib/active_support/current_attributes.rb#L210
[Object#with]: https://github.com/rails/rails/blame/2d6b02bad6b02bf1d26c26461406bda710181244/activesupport/lib/active_support/core_ext/object/with.rb#L26

Author: seanpdoyle

activesupport/lib/active_support/current_attributes.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "active_support/callbacks"
+require "active_support/core_ext/object/with"
 require "active_support/core_ext/enumerable"
 require "active_support/core_ext/module/delegation"
 
@@ -207,12 +208,8 @@ def initialize
     #       end
     #     end
     #   end
-    def set(set_attributes)
-      old_attributes = compute_attributes(set_attributes.keys)
-      assign_attributes(set_attributes)
-      yield
-    ensure
-      assign_attributes(old_attributes)
+    def set(attributes, &block)
+      with(**attributes, &block)
     end
 
     # Reset all attributes. Should be called before and after actions, when used as a per-request singleton.
@@ -221,14 +218,5 @@ def reset
         self.attributes = {}
       end
     end
-
-    private
-      def assign_attributes(new_attributes)
-        new_attributes.each { |key, value| public_send("#{key}=", value) }
-      end
-
-      def compute_attributes(keys)
-        keys.index_with { |key| public_send(key) }
-      end
   end
 end

activesupport/test/current_attributes_test.rb

@@ -144,6 +144,12 @@ def after_teardown
 
     assert_equal "world/1", Current.world
     assert_equal "account/1", Current.account
+
+    hash = { world: "world/2", account: "account/2" }
+    Current.set(hash) do
+      assert_equal "world/2", Current.world
+      assert_equal "account/2", Current.account
+    end
   end
 
   test "using keyword arguments" do