Rails 8 introduces a new feature allowing developers to mark Active Record associations as deprecated using the `deprecated: true` option. This enables safe removal of old associations by providing deprecation warnings when they're accessed, queried, or trigger side effects. The feature supports three modes: warn (logs warnings), raise (throws exceptions), and notify (emits events for external services). Developers can configure these settings globally or per environment, making it easier to phase out legacy associations in large codebases while maintaining safety through gradual deprecation.
Table of contents
Marking an association as deprecatedWorking with different association typesReporting modes and backtrace supportWhy deprecate rather than remove?32 Impressions