Merge pull request #45842 from trevorturk/validate-expires-at

Log a warning if ActiveSupport::Cache is given an expiration in the past

activesupport/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Log a warning if `ActiveSupport::Cache` is given an expiration in the past.
+
+    *Trevor Turk*
+
 *   Add `skip_nil:` support to `ActiveSupport::Cache::Store#fetch_multi`.
 
     *Daniel Alfaro*

activesupport/lib/active_support/cache.rb

@@ -718,6 +718,10 @@ def merged_options(call_options)
             expires_at = call_options.delete(:expires_at)
             call_options[:expires_in] = (expires_at - Time.now) if expires_at
 
+            if call_options[:expires_in]&.negative?
+              ActiveSupport::Cache::Store.logger&.warn("Cache expiration is in the past")
+            end
+
             if options.empty?
               call_options
             else

activesupport/test/cache/behaviors/cache_store_behavior.rb

@@ -566,6 +566,14 @@ def test_expires_in_and_expires_at
     assert_equal "Either :expires_in or :expires_at can be supplied, but not both", error.message
   end
 
+  def test_expires_at_logs_a_warning_if_in_the_past
+    buffer = StringIO.new
+    @cache.logger = ActiveSupport::Logger.new(buffer)
+    key = SecureRandom.uuid
+    @cache.write(key, "bar", expires_at: 1.minute.ago)
+    assert_match %r{Cache expiration is in the past}, buffer.string
+  end
+
   def test_race_condition_protection_skipped_if_not_defined
     key = SecureRandom.alphanumeric
     @cache.write(key, "bar")