Replaces the hand-rolled shopifyFetch wrapper and raw query strings with
the hydrogen preview package (0.0.0-preview-116d5d7-20260730141607), the
same build pinned in hydrogen-preview/.
- services/shopify/client: createStorefrontClient({type: "public"}) with a
static request context. Two module-scoped clients — uncached for carts,
products and customers; revalidate-3600 for shop policies — using the
client's custom fetch option to carry Next's caching hints.
- graphql/*: every document wrapped in gql(), fragments composed via the
second argument instead of string interpolation, and $country/$language
declared with @inContext so hydrogen injects them.
- shopifyFetch keeps its {query, variables} call shape so call sites are
unchanged, but is now generic over the document, so data is inferred. It
re-raises GraphQL errors, which hydrogen returns rather than throws.
Env var names, the 2025-07 API version pin, and the client-side fetching
architecture are unchanged.
Turning on type coverage surfaced real defects, not just annotations:
- hydrogen gql check caught $discountCodes: [String!] used where the field
requires [String!]!.
- Cart and customer mutation payloads are nullable and were dereferenced
unconditionally, so a failed mutation threw a TypeError. Adds a shared
unwrapCartPayload helper (collapsing five copies of the same userErrors
check) and explicit null handling in the customer service, so a null
payload reads as an error rather than success with no errors.
- Search results are a Product | Page | Article union; adds __typename to
the queries and narrows on it.
- Widens nullable fields (altText, image, customer.email, totalTaxAmount)
in the domain interfaces and in the structural duplicates some
components declare locally.
Adds a typecheck script (tsc --noEmit && hydrogen gql check); it passes
with 0 errors. Two deprecation warnings are left alone as acting on them
would change behaviour: ProductOption.values and CartCost.totalTaxAmount.
Verified against mock.shop: build prerenders the policy pages through the
cached client, and in the browser the product grid, search with facets,
collection filter round-trip, add-to-cart and quantity update all work.
Customer account flows are untested — they need real credentials.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JaxgqPbFxLsSuLPZom2kdC
