review fixes

2 files changed, 46 insertions, 18 deletions

diff --git a/packages/browser/src/methods/startAssertion.test.ts b/packages/browser/src/methods/startAssertion.test.ts
index 656c419..0a8a16f 100644
--- a/packages/browser/src/methods/startAssertion.test.ts
+++ b/packages/browser/src/methods/startAssertion.test.ts
@@ -45,6 +45,12 @@ const goodOpts3: PublicKeyCredentialRequestOptionsJSON = {
   timeout: 1,
 };
 
+const goodOpts4: PublicKeyCredentialRequestOptionsJSON = {
+  challenge: bufferToBase64URLString(toUint8Array('fizz')),
+  timeout: 1,
+  allowCredentials: [],
+};
+
 beforeEach(() => {
   mockNavigatorGet.mockReset();
   mockSupportsWebauthn.mockReset();
@@ -65,24 +71,44 @@ test('should convert options before passing to navigator.credentials.get(...)',
     },
   );
 
-  const checkWithOpts = async (opts: PublicKeyCredentialRequestOptionsJSON) => {
-    await startAssertion(opts);
-
-    const argsPublicKey = mockNavigatorGet.mock.calls[0][0].publicKey;
-    const credId = argsPublicKey.allowCredentials[0].id;
+  await startAssertion(goodOpts1);
 
-    expect(new Uint8Array(argsPublicKey.challenge)).toEqual(new Uint8Array([102, 105, 122, 122]));
-    // Make sure the credential ID is an ArrayBuffer with a length of 64
-    expect(credId instanceof ArrayBuffer).toEqual(true);
-    expect(credId.byteLength).toEqual(64);
-  };
+  const argsPublicKey = mockNavigatorGet.mock.calls[0][0].publicKey;
+  const credId = argsPublicKey.allowCredentials[0].id;
 
-  await checkWithOpts(goodOpts1);
-  await checkWithOpts(goodOpts3);
+  expect(new Uint8Array(argsPublicKey.challenge)).toEqual(new Uint8Array([102, 105, 122, 122]));
+  // Make sure the credential ID is an ArrayBuffer with a length of 64
+  expect(credId instanceof ArrayBuffer).toEqual(true);
+  expect(credId.byteLength).toEqual(64);
 
   done();
 });
 
+test('should support optional allowCredential', async () => {
+  mockSupportsWebauthn.mockReturnValue(true);
+
+  // Stub out a response so the method won't throw
+  mockNavigatorGet.mockImplementation(
+    (): Promise<any> => {
+      return new Promise(resolve => {
+        resolve({
+          response: {},
+          getClientExtensionResults: () => ({}),
+        });
+      });
+    },
+  );
+
+  await startAssertion(goodOpts3);
+  let allowCredentials = mockNavigatorGet.mock.calls[0][0].allowCredentials;
+  expect(allowCredentials).toEqual(undefined);
+
+  // Should convert empty array to undefined
+  await startAssertion(goodOpts4);
+  allowCredentials = mockNavigatorGet.mock.calls[1][0].allowCredentials;
+  expect(allowCredentials).toEqual(undefined);
+});
+
 test('should return base64url-encoded response values', async done => {
   mockSupportsWebauthn.mockReturnValue(true);
 
diff --git a/packages/browser/src/methods/startAssertion.ts b/packages/browser/src/methods/startAssertion.ts
index fbc6f59..e02e577 100644
--- a/packages/browser/src/methods/startAssertion.ts
+++ b/packages/browser/src/methods/startAssertion.ts
@@ -21,16 +21,18 @@ export default async function startAssertion(
     throw new Error('WebAuthn is not supported in this browser');
   }
 
+  // We need to avoid passing empty array to avoid blocking retrieval
+  // of public key
+  let allowCredentials;
+  if (requestOptionsJSON.allowCredentials?.length !== 0) {
+    allowCredentials = requestOptionsJSON.allowCredentials?.map(toPublicKeyCredentialDescriptor);
+  }
+
   // We need to convert some values to Uint8Arrays before passing the credentials to the navigator
   const publicKey: PublicKeyCredentialRequestOptions = {
     ...requestOptionsJSON,
     challenge: base64URLStringToBuffer(requestOptionsJSON.challenge),
-    // We need to avoid passing empty array to avoid blocking retrieval
-    // of public key
-    allowCredentials:
-      requestOptionsJSON.allowCredentials?.length === 0
-        ? undefined
-        : requestOptionsJSON.allowCredentials?.map(toPublicKeyCredentialDescriptor),
+    allowCredentials,
   };
 
   // Wait for the user to complete assertion