What sorta validation are you thinking about? In most cases, you can check in the response template whether there's been an error, if so, you can throw a custom error, but even if you don't, AppSync will throw the DynamoDB error (e.g. conditional check failed). This error handling behaviour is different between the two versions of template though, it's something that trips me up from time-to-time too.
I was talking about input validation like the middy middleware where you can check for Ajv input. So you can allow for example if the string is valid inside an array. I am curious now how you do this kind of validation with AppSync and Dynamo talking to each other without a lambda. (I never used AppSync and GraphQL)
Nice! But I have one question about proxying from AppSync to DynamoDB, how do you validate the data and return an error response to the client?
What sorta validation are you thinking about? In most cases, you can check in the response template whether there's been an error, if so, you can throw a custom error, but even if you don't, AppSync will throw the DynamoDB error (e.g. conditional check failed). This error handling behaviour is different between the two versions of template though, it's something that trips me up from time-to-time too.
I was talking about input validation like the middy middleware where you can check for Ajv input. So you can allow for example if the string is valid inside an array. I am curious now how you do this kind of validation with AppSync and Dynamo talking to each other without a lambda. (I never used AppSync and GraphQL)
Ah, I see. For those, you can perform validation in the VTL request template.