Describe a compute provider in one place

[rossnelson]

Stacked on #3945. Base is feat/cloud-run-public-preview, so the diff here is the refactor alone. Merge #3945 first.

Description & motivation 💭

A compute provider was described in ten places, in four shapes, under two naming conventions:

Where	Shape
compute-provider-picker — providerIcon	Record
compute-provider-picker — providerLabel()	switch
compute-provider-picker — providerDescription()	switch
compute-provider-picker — defaultProviders	array literal
shared.ts — defaultReleaseStage	Record
compute-badge.svelte — CONFIG	Record, keyed by wire name
lock-compute-provider.ts — providerValue	if-chain over both namings
compute-fields.svelte — templates	5 ?raw imports + provider ternaries

Adding a provider meant finding all ten. The templates were the part that hurt most visibly: seven props (cfnTemplate, cfnTemplateUrl, terraformTemplate, cloudRunTerraformTemplate, agentCoreCfnTemplate, agentCoreCfnTemplateUrl, agentCoreTerraformTemplate) threaded through pages → forms → fields, growing by three with each new provider.

COMPUTE_PROVIDERS now holds all of it and the ten readers derive from it. Adding a provider is one entry.

The exhaustiveness is the point

The union derives from a tuple, not the other way round, and the maps are annotated rather than cast:

export const COMPUTE_PROVIDER_VALUES = ['lambda', 'agentcore', 'cloud-run'] as const;
export type ComputeProviderValue = (typeof COMPUTE_PROVIDER_VALUES)[number];

export const COMPUTE_PROVIDERS: Record<ComputeProviderValue, ComputeProviderDefinition> = { ... };

I verified this rather than assuming it. Adding a fourth provider to the tuple produces six compile errors naming it — in the registry, the release-stage map, and all three form schemas:

Property '"azure-functions"' is missing in type '{ lambda: ...; agentcore: ...; 'cloud-run': ... }'
  but required in type 'Record<"lambda" | "agentcore" | "cloud-run" | "azure-functions", ...>'

The same rule covers consumers. templates is one exhaustive map, so Temporal Cloud — which overrides them per environment — fails its own type check when a provider is added without templates, instead of silently falling back to the bundled defaults and showing a customer an infrastructure snippet pointing at the wrong account.

Design Considerations 🎨

• Annotation, not satisfies. satisfies preserves literal types, which drops optional fields from the union — terraformModuleHref became unreachable because Cloud Run has none. The annotation gives exhaustiveness and uniform access.
• i18n keys are typed as keys, not string. labelKey: I18nKey<I18nResources> means a typo is a compile error rather than a label rendering as workers.provider-lamda.
• No casts on the provider. provider arrives as a form field, so it is narrowed through computeProviderFromType rather than asserted. An unrecognised value stays unrecognised instead of reading as a provider with no entry.
• Two asymmetries are modelled, not inferred. CloudFormation is AWS-only, so it is optional on the templates type and Cloud Run simply has none — replacing the isAgentCore ternaries that decided it. The Terraform module link is per provider rather than an AWS-only string built from a boolean.
• A ternary disappears entirely. interpolateTerraformTemplate already no-ops on whichever ARN key is absent from a snippet — its own comment said so — so both are passed.

What this does not touch

The {#if provider === 'lambda'} blocks in compute-fields.svelte markup. Those render genuinely different inputs and belong where they are.

Testing 🧪

How was this tested 👻

• Behaviour-preserving; existing tests unchanged except where they passed the old props
• Exhaustiveness verified by adding a provider and reading the errors
• Verified against the real consumer

135 passed across the worker, deployment, and utility suites. count-strict-errors.ts reports 0.

Verified against a downstream consumer by building a package from this branch and type-checking it there: no new errors.

compute-fields.test.ts is the only test that changed shape — it passed two template props, and now layers an override onto the default map.

Checklists

Merge Checklist

• Zero strict errors
• Verified against a downstream consumer built from this branch
• Merge Move Cloud Run to public preview #3945 first

Issue(s) closed

None — groundwork so the next provider is one entry rather than ten edits.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
holocene	Ready	Preview	Sep 19, 2026 10:39pm UTC