Follow-up to #49131. For `AWS_NIMBUS` orgs, the new-project form's
Region trigger could show a region that wasn't in the dropdown at all
(e.g. "Southeast Asia (Singapore)" while the list only offered "East US
(North Virginia)"). The geolocation-based default region
(`useDefaultRegionQuery`) picked the nearest region from **all** AWS
regions and seeded it into `dbRegion` unvalidated, ignoring the
provider's restricted region list.
**Changed:**
- `getDefaultRegionOption` now computes the nearest region only over the
provider's available regions (new `getDefaultRegionCandidateKeys`
helper). The flag-based restricted pool (`defaultRegionRestrictedPool`)
narrows within that set and is ignored if the intersection would be
empty.
- The form's default-region selection is extracted into
`resolveDefaultDbRegion` (`ProjectCreation.utils.ts`): High Availability
region first, then the recommended smart region, then the geolocated
default — used only when the provider actually offers that region —
falling back to the provider's static default.
- `getAvailableRegions` takes an injectable `environment` param (same
pattern as `getHighAvailabilityRegionCode`) so the prod-only Nimbus
region list is unit-testable.
**Added:**
- Unit tests for `getDefaultRegionCandidateKeys` (provider clamping
incl. Nimbus on prod, restricted-pool intersection, empty-intersection
fallback), `getAvailableRegions` across environments, and
`resolveDefaultDbRegion` (branch priority plus the fallback when the
geolocated region isn't offered).
## To test
- Emulate a Nimbus org locally by setting `"infra:cloud_providers":
["AWS_NIMBUS"]` in
`apps/studio/hooks/custom-content/custom-content.json`, then open the
new-project form: the Region trigger must show the same region the
dropdown offers (locally that's only Southeast Asia (Singapore)). To
reproduce the original mismatch path, stub
`https://www.cloudflare.com/cdn-cgi/trace` to return `loc=US` — the
trigger should still be clamped to the provider's region rather than
showing a US region
- Block or fail the Cloudflare trace request: the trigger should fall
back to the provider's static default region, not sit blank or loading
- Restore the normal provider list: the smart-region flow ("General
regions" + "Specific regions" with Recommended badges) is unaffected —
the geolocation request doesn't even fire on that path — and toggling
High Availability still transitions the region list cleanly
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
## Summary by CodeRabbit
- **Bug Fixes**
- Region suggestions now respect the selected cloud provider and
deployment environment.
- Project creation avoids unavailable geolocated regions and falls back
to a supported provider default.
- Restricted region pools now fall back reliably to available provider
regions.
- AWS Nimbus selection reflects the active environment while preserving
high-availability and smart-region behavior.
- **Tests**
- Added coverage for provider-specific, environment-specific,
restricted, and fallback region selection scenarios.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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Co-authored-by: Alaister Young <10985857+alaister@users.noreply.github.com>
