0_query.graphql

# Query coming to gateway

query(
  $id: ID! # overriden in parameters, so it won't be included
) {
  node(id: $id) { # delegate to userById
    # This is a selection set from the node resolver
    id # This field doesn't exist in User
    ...BlogFragment # Blog can't be spread here
    ...UserFragment
  }
}

# This fragment is used, so should be included
fragment UserFragment on User {
  username
}

# This fragment isn't used, so should be removed
fragment BlogFragment on Blog {
  title
}

1_result.graphql

# Query sent to service

query(
  $_v0_id: ID! # generated variable name
) {
  userById(id: $_v0_id) {
    ...UserFragment
  }
}

fragment UserFragment on User {
  username
}