test(sql-orm-client): preserve literal capability types in withCapabilities

Replace the `as unknown as TestContract` cast with a generic over
`TCaps extends Record<string, Record<string, boolean>>`, returning
`Omit<TestContract, 'capabilities'> & { readonly capabilities: TCaps }`.
Capability-dependent type checks now see the caller's literal
capability shape instead of the narrow `TestContract` slot.

Addresses @aqrln's review note: "I'd make this helper produce an
accurate contract types from day one if it's not too complex."

Widens `contextForContract` and `createCollectionFor` in
`collection-fixtures.ts` to accept `Contract<SqlStorage>` so the more
precise return type flows through; the existing internal cast inside
`contextForContract` already absorbs the structural gap. Drops the
explicit `: TestContract` return annotations on the two thin
`with…Capabilities` wrappers in `collection-dispatch.test.ts` so the
inferred result keeps its literal capability shape.

All 481 sql-orm-client tests pass.

Author: Sævar Berg

packages/3-extensions/sql-orm-client/test/collection-dispatch.test.ts

@@ -8,7 +8,7 @@ import { createCollectionFor } from './collection-fixtures';
 import type { MockRuntime, TestContract } from './helpers';
 import { createMockRuntime, getTestContract, withCapabilities } from './helpers';
 
-function withSingleQueryCapabilities(contract: TestContract): TestContract {
+function withSingleQueryCapabilities(contract: TestContract) {
   return withCapabilities(contract, {
     ...contract.capabilities,
     [contract.targetFamily]: {
@@ -30,7 +30,7 @@ function withSingleQueryCapabilities(contract: TestContract): TestContract {
  * contract" — the regression scenario the principled namespaced lookup
  * was introduced to handle.
  */
-function withEmittedSqlCapabilities(contract: TestContract): TestContract {
+function withEmittedSqlCapabilities(contract: TestContract) {
   return withCapabilities(contract, {
     sql: { jsonAgg: true, returning: true },
     postgres: { jsonAgg: true, lateral: true, returning: true },

packages/3-extensions/sql-orm-client/test/collection-fixtures.ts

@@ -1,3 +1,5 @@
+import type { Contract } from '@prisma-next/contract/types';
+import type { SqlStorage } from '@prisma-next/sql-contract/types';
 import type { ExecutionContext } from '@prisma-next/sql-relational-core/query-lane-context';
 import { Collection } from '../src/collection';
 import type { MockRuntime, TestContract } from './helpers';
@@ -7,15 +9,15 @@ export type TestModelName = Extract<keyof TestContract['models'], string>;
 
 export const baseContract = getTestContract();
 
-function contextForContract(contract: TestContract): ExecutionContext<TestContract> {
+function contextForContract(contract: Contract<SqlStorage>): ExecutionContext<TestContract> {
   const base = getTestContext();
   if (contract === baseContract) return base;
   return { ...base, contract } as ExecutionContext<TestContract>;
 }
 
 export function createCollectionFor<ModelName extends TestModelName>(
   modelName: ModelName,
-  contract: TestContract = baseContract,
+  contract: Contract<SqlStorage> = baseContract,
 ): {
   collection: Collection<TestContract, ModelName>;
   runtime: MockRuntime;

packages/3-extensions/sql-orm-client/test/helpers.ts

@@ -27,19 +27,21 @@ export function getTestContract(): TestContract {
 /**
  * Override the capabilities of a {@link TestContract} for a test scenario.
  *
- * The narrow `TestContract` type fixes capabilities to the exact shape
- * found in `fixtures/generated/contract.json` (e.g. the `postgres`
- * namespace's specific readonly fields). Tests need to construct
- * contracts with arbitrary capability shapes — empty, only-jsonAgg,
- * cross-namespace, etc. — that don't fit that narrow type.
+ * The narrow `TestContract` type fixes `capabilities` to the literal shape
+ * generated for `fixtures/generated/contract.json`. Tests need contracts
+ * with arbitrary capability shapes — empty, only-jsonAgg, cross-namespace,
+ * etc. — and want the override's literal types preserved so capability-
+ * dependent type checks remain meaningful.
  *
- * This helper centralizes the structural cast so call sites stay clean.
+ * The result widens `TestContract`'s `capabilities` slot to the caller's
+ * `TCaps`, which the framework `Contract` interface already permits
+ * (`capabilities: Record<string, Record<string, boolean>>`).
  */
-export function withCapabilities(
+export function withCapabilities<TCaps extends Record<string, Record<string, boolean>>>(
   contract: TestContract,
-  capabilities: Record<string, Record<string, boolean>>,
-): TestContract {
-  return { ...contract, capabilities } as unknown as TestContract;
+  capabilities: TCaps,
+): Omit<TestContract, 'capabilities'> & { readonly capabilities: TCaps } {
+  return { ...contract, capabilities };
 }
 
 const testContext: ExecutionContext<TestContract> = createExecutionContext({