Current GraphQL exporter needs refactoring

[jdacoello]

Argument 1 - Current GraphQL structure is of little use

The current GraphQL exporter creates a new type for every vss element (branch, attribute, sensor, actuator). For example:

type Vehicle {
  vehicleIdentification: Vehicle_VehicleIdentification
  ...
}

type Vehicle_VehicleIdentification {
  ...
}
...

type Vehicle_VehicleIdentification_Brand {
  value: String
  timestamp: String
}

However, this method is not effectively using the expressiveness that the GraphQL schema language offers. Ideally, a type should be the feature of interest to which multiple fields are linked. In this example, a better option would be:

type Vehicle_VehicleIdentification {
  brand: String
  ...
}

Argument 2 - VSS modeling can be entirely done in GraphQL Schema Language

The idea of evolving VSS from a tree to a graph has been already discussed a few times in COVESA. As a result, an evolution plan has been suggested and documented here.

To that end, the first step is to improve this exporter. So, a PR to solve this particular issue is on the making and its progress can be consulted in the feature set documentation or directly in the developing branch.