RTDB Emulator allows write / read to a DB without a namespace

[abeisgoat]

If you spin up the RTDB emulator, you can do...

curl -XPOST -d '"Data!"' localhost:9000/test.json

then

curl -XGET localhost:9000/test.json

These ops succeed but do not trigger functions as they appear to be going to some invisible (default?) namespace. Maybe we should make ops without an ns flag point to the only know ns if there's only one, otherwise return an error?

[yuchenshi]

This is tracked internally as b/149930367. But tl;dr, right now there is a default value for ns which is a default namespace. Well, you'll see its name in Emulator UI, and you'll see why it isn't the most intuitive default.