Add no disclosure assertion

test/no-disclosures.test.ts

@@ -0,0 +1,52 @@
+import * as jose from 'jose'
+import sd from '../src'
+const alg = 'ES256';
+// based on https://w3c.github.io/vc-data-model/#example-a-simple-example-of-a-verifiable-credential
+const claimset = `
+"@context":
+  - https://www.w3.org/ns/credentials/v2
+  - https://www.w3.org/ns/credentials/examples/v2
+id: http://university.example/credentials/3732
+type:
+  - VerifiableCredential
+  - ExampleDegreeCredential
+issuer:
+  id: https://university.example/issuers/565049
+  name:
+    - value: test value 0
+      lang: en
+    - value: test value 1
+      lang: en
+    - value: test value 2
+      lang: en
+    - value: test value 3
+      lang: en
+    - value: test value 4
+      lang: en
+validFrom: 2015-05-10T12:30:00Z
+credentialStatus:
+  - id: https://vendor.example/status-list/urn:uuid:d31ada5d-1d3d-4f68-8587-8ff9bb3038d6#0
+    type: StatusList2021Entry
+    statusPurpose: revocation
+    statusListIndex: "0"
+    statusListCredential: https://vendor.example/status-list/urn:uuid:d31ada5d-1d3d-4f68-8587-8ff9bb3038d6
+credentialSubject:
+  id: did:example:ebfeb1f712ebc6f1c276e12ec21
+  degree:
+    type: ExampleBachelorDegree
+    subtype: Bachelor of Science and Arts
+`;
+
+it('simple setup', async () => {
+  const { publicKeyJwk, secretKeyJwk } = await sd.key.generate(alg);
+  const vc = await sd.issuer({ secretKeyJwk })
+    .issue({
+      holder: publicKeyJwk,
+      claimset
+    })
+  const decodedHeader = jose.decodeProtectedHeader(vc)
+  expect(decodedHeader).toEqual({ alg: 'ES256' })
+  const decodedPayload = jose.decodeJwt(vc)
+  // even with no disclosures, "_sd_alg" is set
+  expect(decodedPayload._sd_alg).toBe('sha-256')
+});