Safely Roll Out Strict Error Handling in Your GraphQL Codebase

Session description

Last year we introduced strict error handling - with @throwOnFieldError as an example of how this can be accomplished. This year, we’ll discuss how to safely roll it out. You’ve had a GraphQL codebase that weakly handled server-side errors for years. Now, you have the tools (directives, hooks, handlers, and language features) that let you treat field errors properly. However, it’s a daunting task to suddenly explode queries en-masse by flipping a switch. This move is powerful, but requires a thoughtful and data-driven approach to do safely. In this talk we’ll cover: * Preparing the groundwork for migration to stricter error handling * Using data to make informed decisions about fragment/query behavior * Gating your change at a singular point * Scaling the rollout to a large codebase * How we’re approaching this rollout at Meta