RateLimiting Cleanups

Followup: rails#50781

Some small issues I failed to address in the original PR.

Author: byroot

actionpack/test/controller/rate_limiting_test.rb

@@ -4,13 +4,13 @@
 
 class RateLimitedController < ActionController::Base
   self.cache_store = ActiveSupport::Cache::MemoryStore.new
-  rate_limit to: 2, within: 2.seconds, by: -> { Thread.current[:redis_test_seggregation] }, only: :limited_to_two
+  rate_limit to: 2, within: 2.seconds, only: :limited_to_two
 
   def limited_to_two
     head :ok
   end
 
-  rate_limit to: 2, within: 2.seconds, by: -> { Thread.current[:redis_test_seggregation] }, with: -> { head :forbidden }, only: :limited_with
+  rate_limit to: 2, within: 2.seconds, by: -> { params[:rate_limit_key] }, with: -> { head :forbidden }, only: :limited_with
   def limited_with
     head :ok
   end
@@ -44,6 +44,16 @@ class RateLimitingTest < ActionController::TestCase
     end
   end
 
+  test "limit by" do
+    get :limited_with
+    get :limited_with
+    get :limited_with
+    assert_response :forbidden
+
+    get :limited_with, params: { rate_limit_key: "other" }
+    get :limited_with
+  end
+
   test "limited with" do
     get :limited_with
     get :limited_with

activesupport/lib/active_support/cache/file_store.rb

@@ -210,13 +210,12 @@ def search_dir(dir, &callback)
         # Modifies the amount of an integer value that is stored in the cache.
         # If the key is not found it is created and set to +amount+.
         def modify_value(name, amount, options)
-          file_name = normalize_key(name, options)
           options = merged_options(options)
           key = normalize_key(name, options)
           version = normalize_version(name, options)
           amount = Integer(amount)
 
-          lock_file(file_name) do
+          lock_file(key) do
             entry = read_entry(key, **options)
 
             if !entry || entry.expired? || entry.mismatched?(version)