fix: remove the unverified subscription when push verification fails, and poll through a network blip

lib/__tests__/web-push.test.ts

@@ -488,6 +488,68 @@ describe('enableWebPush when the verification does not come', () => {
 
   afterEach(() => { vi.useRealTimers(); });
 
+  it('keeps polling through a network blip', async () => {
+    vi.useFakeTimers();
+    const client = makeClient([]);
+    let polls = 0;
+    const fetchMock = vi.fn(async (input: RequestInfo | URL) => {
+      const url = String(input);
+      const json = (body: unknown) => ({ ok: true, status: 200, json: async () => body }) as Response;
+      if (url.endsWith('/api/push/vapid-public-key')) return json({ publicKey: 'QUJD' });
+      if (url.includes('/api/push/verify/')) {
+        polls += 1;
+        if (polls === 1) throw new TypeError('Failed to fetch');
+        return json({ verificationCode: 'code' });
+      }
+      return json({});
+    });
+    vi.stubGlobal('fetch', fetchMock);
+
+    const settled = enableWebPush({ client, relayBaseUrl: RELAY, inboxOnly: false }).then(() => 'done', (error: Error) => error.message);
+    await vi.advanceTimersByTimeAsync(5_000);
+
+    expect(await settled).toBe('done');
+    expect(client.verifyPushSubscription).toHaveBeenCalledWith('push-new', 'code');
+  });
+
+  it('removes its unverified subscription and reads as off when the code never comes', async () => {
+    vi.useFakeTimers();
+    const client = makeClient([]);
+    installSilentRelay(() => false);
+
+    const settled = enableWebPush({ client, relayBaseUrl: RELAY, inboxOnly: false }).then(() => 'done', (error: Error) => error.message);
+    await vi.advanceTimersByTimeAsync(120_000);
+
+    expect(await settled).toMatch(/verif/i);
+    expect(client.destroyed).toEqual(['push-new']);
+    expect(localStorage.getItem(SUB_KEY)).toBeNull();
+    expect(client.verifyPushSubscription).not.toHaveBeenCalled();
+  });
+
+  it('removes its subscription when the server refuses the code', async () => {
+    const client = makeClient([]);
+    installFetch({});
+    (client.verifyPushSubscription as ReturnType<typeof vi.fn>).mockRejectedValueOnce(new Error('Verification code does not match.'));
+
+    await expect(enableWebPush({ client, relayBaseUrl: RELAY, inboxOnly: false })).rejects.toThrow('does not match');
+
+    expect(client.destroyed).toEqual(['push-new']);
+    expect(localStorage.getItem(SUB_KEY)).toBeNull();
+  });
+
+  it('keeps the old subscription working when its replacement fails verification', async () => {
+    localStorage.setItem(DEVICE_KEY, THIS_DEVICE);
+    localStorage.setItem(SUB_KEY, 'push-old');
+    const client = makeClient([sub('push-old', THIS_DEVICE)]);
+    installFetch({});
+    (client.verifyPushSubscription as ReturnType<typeof vi.fn>).mockRejectedValueOnce(new Error('nope'));
+
+    await expect(enableWebPush({ client, relayBaseUrl: RELAY, inboxOnly: false, forceRecreate: true })).rejects.toThrow('nope');
+
+    expect(client.destroyed).toEqual(['push-new']);
+    expect(localStorage.getItem(SUB_KEY)).toBe('push-old');
+  });
+
   it('touches the subscription after the server\'s minute, which makes it send the code', async () => {
     vi.useFakeTimers();
     const client = makeClient([]);

lib/web-push.ts

@@ -658,12 +658,16 @@ async function pollVerificationCode(
       askedAgain = true;
       await askAgain().catch(() => undefined);
     }
-    const res = await fetch(
-      buildRelayUrl(relayBaseUrl, `/api/push/verify/${encodeURIComponent(subscriptionId)}`),
-    );
-    if (res.ok) {
-      const body = (await res.json()) as { verificationCode?: string | null };
-      if (body.verificationCode) return body.verificationCode;
+    try {
+      const res = await fetch(
+        buildRelayUrl(relayBaseUrl, `/api/push/verify/${encodeURIComponent(subscriptionId)}`),
+      );
+      if (res.ok) {
+        const body = (await res.json()) as { verificationCode?: string | null };
+        if (body.verificationCode) return body.verificationCode;
+      }
+    } catch {
+      // A blip on the way to the relay; the code is still coming.
     }
     await new Promise((r) => setTimeout(r, delay));
     delay = Math.min(delay * 1.5, 2000);
@@ -881,10 +885,17 @@ export async function enableWebPush(
   const serverAssignedId = created.result;
   rememberRefusedEmailPushAccounts(accountId, refusedBefore, emailPush, created.emailPush);
 
-  const verificationCode = await pollVerificationCode(relayBaseUrl, deviceClientId, () =>
-    params.client.updatePushSubscription(serverAssignedId, { expires: expiresFromNow(SUBSCRIPTION_EXPIRES_DAYS) }),
-  );
-  await params.client.verifyPushSubscription(serverAssignedId, verificationCode);
+  try {
+    const verificationCode = await pollVerificationCode(relayBaseUrl, deviceClientId, () =>
+      params.client.updatePushSubscription(serverAssignedId, { expires: expiresFromNow(SUBSCRIPTION_EXPIRES_DAYS) }),
+    );
+    await params.client.verifyPushSubscription(serverAssignedId, verificationCode);
+  } catch (err) {
+    // Unverified, it never delivers anything, takes up one of the account's
+    // places and stands in the way of the next verification.
+    await params.client.destroyPushSubscription(serverAssignedId).catch(() => undefined);
+    throw err;
+  }
   localStorage.setItem(subIdKey, serverAssignedId);
   localStorage.setItem(relayBaseKey(accountId), relayBaseUrl);
   if (replacedServerId) {