rails-query-object

Query objects encapsulate complex Rails database queries by exposing a call method that returns an ActiveRecord::Relation or Hash. This design pattern isolates query logic in app/queries to promote reusability, testability, and clearer data access patterns.

You test complex ActiveRecord queries using TDD by writing a failing spec in spec/queries/ first, implementing the query object in app/queries/, and running the specs to green. This ensures your query logic is validated before integration.

Yes, you can use query objects to enforce multi-tenancy in Rails apps by accepting context like user or account via the constructor. This ensures the query automatically scopes records and returns only data relevant to the specified tenant.

The best way to structure aggregations in Rails query objects is to have the call method return a Hash instead of an ActiveRecord::Relation. This approach neatly encapsulates aggregated data while following standard query composition conventions.

You should not use a query object for ActiveRecord when your queries are simple enough to reside directly in the model. Query objects are designed to encapsulate complex database queries and aggregations, so trivial scopes do not require this pattern.