fix: .provide inference regression (#242)

* chore: create a failing test

* fix: type misalignment

packages/interface/src/capability.ts

@@ -6,7 +6,6 @@ import {
   Failure,
   PrincipalParser,
   PrincipalResolver,
-  Signer,
   URI,
   UCANLink,
   Await,
@@ -182,10 +181,9 @@ export interface TheCapabilityParser<M extends Match<ParsedCapability>>
  * When normalize capabilities by removing `nb` if it is a `{}`. This type
  * does that normalization at the type level.
  */
-export type InferCapability<T extends ParsedCapability> =
-  keyof T['nb'] extends never
-    ? { can: T['can']; with: T['with'] }
-    : { can: T['can']; with: T['with']; nb: T['nb'] }
+export type InferCapability<T extends Capability> = keyof T['nb'] extends never
+  ? { can: T['can']; with: T['with'] }
+  : { can: T['can']; with: T['with']; nb: T['nb'] }
 
 /**
  * In delegation capability all the `nb` fields are optional. This type maps

packages/interface/src/lib.ts

@@ -34,6 +34,7 @@ import {
   DIDKeyResolutionError,
   ParsedCapability,
   CapabilityParser,
+  InferCapability,
 } from './capability.js'
 import type * as Transport from './transport.js'
 import type { Tuple, Block } from './transport.js'
@@ -746,7 +747,9 @@ export type KeyArchive<Alg extends SigAlg = SigAlg> =
 
 export type InferInvokedCapability<
   C extends CapabilityParser<Match<ParsedCapability>>
-> = C extends CapabilityParser<Match<infer T>> ? T : never
+> = C extends CapabilityParser<Match<infer T>>
+  ? InferCapability<T & Capability>
+  : never
 
 export type Intersection<T> = (T extends any ? (i: T) => void : never) extends (
   i: infer I

packages/server/test/handler.spec.js

@@ -206,3 +206,35 @@ test('checks for single capability invocation', async () => {
     ],
   })
 })
+
+test('test access/claim provider', async () => {
+  const server = Server.create({
+    id: w3,
+    service: { access: Access },
+    decoder: CAR,
+    encoder: CBOR,
+  })
+
+  /**
+   * @type {Client.ConnectionView<{
+   *  access: {
+   *    claim: API.ServiceMethod<API.InferInvokedCapability<typeof Access.claimCapability>, never[], never>
+   *  }
+   * }>}
+   */
+  const client = Client.connect({
+    id: w3,
+    encoder: CAR,
+    decoder: CBOR,
+    channel: server,
+  })
+
+  const claim = Access.claimCapability.invoke({
+    issuer: alice,
+    audience: w3,
+    with: alice.did(),
+  })
+
+  const result = await claim.execute(client)
+  assert.deepEqual(result, [])
+})

packages/server/test/service/access.js

@@ -1,5 +1,6 @@
 import * as Server from '../../src/server.js'
 import { provide } from '../../src/handler.js'
+import { DID } from '@ucanto/validator'
 import * as API from './api.js'
 import { service as w3 } from '../fixtures.js'
 export const id = w3
@@ -33,6 +34,11 @@ const identifyCapability = Server.capability({
     new Server.Failure(`Can not derive ${claimed.with} from ${claimed.with}`),
 })
 
+export const claimCapability = Server.capability({
+  can: 'access/claim',
+  with: DID.match({ method: 'key' }).or(DID.match({ method: 'mailto' })),
+})
+
 /**
  * @typedef {Map<API.DID|API.URI<"mailto:">, {account:API.DID, proof:API.Link}>} Model
  * @type {Model}
@@ -74,6 +80,13 @@ export const identify = provide(
   }
 )
 
+export const claim = provide(
+  claimCapability,
+  async function claim({ capability }) {
+    return []
+  }
+)
+
 /**
  * @param {Model} accounts
  * @param {API.DID} from