Env

Node: 2.3.3
gcloud: 0.21.0

Problem

dataset.key(['Tracking2', "556ba07cbeb676ba7e9458e8"]) => key path: name =556ba07cbeb676ba7e9458e8
but
dataset.key(['Tracking2', "55479506996815820615e988"]) => key path: id=-9204792730274402000

Root cause

https://github.com/GoogleCloudPlatform/gcloud-node/blob/master/lib/datastore/entity.js#L227

> isNaN("556ba07cbeb676ba7e9458e8")
true
> isNaN("55479506996815820615e988")
false

explain: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/isNaN#Description