decision(storage-resize-images): kit/extension parity – FUNCTION_DEFAULT_REGION is required but BUCKET_REGION overrides it #3274

storage-resize-images kit/extension parity. Priority: low. Users must set FUNCTION_DEFAULT_REGION, but it has no effect when BUCKET_REGION is set, and region errors name neither param.

Difference

functions:kits:install writes a wrapper that declares a required FUNCTION_DEFAULT_REGION param, described as the "Global default region where functions should be deployed" (from the CLI's index-kit.ts template). The kit's own BUCKET_REGION overrides it. The extension has a single location setting.

Reproduced

The README says an empty BUCKET_REGION= keeps the deployed region, or falls back to us-central1 or FIREBASE_FUNCTIONS_DEFAULT_REGION. Neither held: with FUNCTION_DEFAULT_REGION=us-central1 and FIREBASE_FUNCTIONS_DEFAULT_REGION=europe-west4, the variable was ignored. Redeploying an existing europe-west4 instance after changing FUNCTION_DEFAULT_REGION tried to move it. The README's Configuration table doesn't list FUNCTION_DEFAULT_REGION.

Code

• Kit: config.ts#L345-L347, index.ts#L98-L107; README at README.md#L260-L268.

Resolution

Two options:

• Correct the README's empty-BUCKET_REGION paragraph and document FUNCTION_DEFAULT_REGION as the fallback.
• Ask firebase-tools not to generate a region param for kits that place their own functions.

#3159 documented matching FUNCTION_DEFAULT_REGION to the bucket for migration.