In the sentence:
"Above is the simplest possible validation function, which, when deployed, would allow all updates regardless of content or user roles. The converse, which never lets anyone do anything, looks like this:
function(newDoc, oldDoc, userCtx) {
throw({forbidden : 'no way'});
}
"
...would allow all updates...
should be:
...would deny all updates...
In the sentence: "Above is the simplest possible validation function, which, when deployed, would allow all updates regardless of content or user roles. The converse, which never lets anyone do anything, looks like this: function(newDoc, oldDoc, userCtx) { throw({forbidden : 'no way'}); } " ...would allow all updates... should be: ...would deny all updates...
regards