Cross-resource constraints #88
Description
We're building an S3 bucket notification resource, to solve a long-standing problem. Each item in the notification configuration for a bucket is a separate resource. However, the rules for bucket notifications says they can't overlap in prefix+events. So two resources can share a prefix if they subscribe to different events, or if they share events they can't share a prefix. If someone creates set of resources that violates these constraints, the S3 API call will return an error at some point in the process, which we'll surface to the user. But it got me thinking if these kinds of constraints could be expressed in the schema. It could be something like "uniquePropertySets": {"SomeNameForThis": [ '#/properties/SomeScalarProperty', '#/properties/SomeSetValuedProperty']}