docs(delete-user-data): kit/extension parity – manual setup deploys to us-east1, README says us-central1 #3252

delete-user-data kit/extension parity. Priority: medium. The README says the wrong region for manual setups, so functions handle user data in an unexpected region.

Difference

• Extension: functions deploy to the location chosen at install, us-central1 by default. I tested europe-west1 and that worked too.
• Kit: the README says the functions deploy to "your codebase's default (us-central1 unless you have changed it)". In practice, firebase-tools 15.31 puts all three functions in us-east1. Pub/Sub and Auth triggers with no region resolve to DEFAULT_GLOBAL_TRIGGER_REGION = "us-east1" (firebase-tools services/index.ts).

Not pinning a region is already an accepted kit difference. What's wrong is the documentation. The CLI install paths avoid this: firebase functions:kits:install and ext:migrate generate an entry file that sets setGlobalOptions({ region }) from FUNCTION_DEFAULT_REGION, and a migrated instance landed in its extension's region. Only the README's manual setup hits us-east1.

Reproduced

A deploy with no region set created kit-<id>-clearData, -handleSearch and -handleDeletion in us-east1. The extension instances deployed to us-central1 and europe-west1, as configured.

An earlier test suggested that from us-east1, a large recursive delete in a nam5 database timed out and left data behind. A retest didn't reproduce this. With FIRESTORE_PATHS=rec/{UID}, recursive mode and 20,000 docs under rec/<uid>/items, 4 runs each:

So the problem here is the documentation, not a measured failure. Data is still processed outside the region a reader would expect.

Code

• Extension: no location in resources; the platform applies the install-time location (extension.yaml#L59-L86).
• Kit: no region set (index.ts#L112-L135); the claim is in README.md#L190-L194.

Resolution

Correct the README: say functions land in us-east1 unless a region is set, and point readers to firebase functions:kits:install, which prompts for FUNCTION_DEFAULT_REGION. Document calling setGlobalOptions({ region }) before the kit loads, the same way the CLI's kit init template uses FUNCTION_DEFAULT_REGION. In an ES module, import / export … from load the kit before the rest of the entry file runs, so the call belongs in a separate module imported first.