fix: show an error when the server refuses a push registration change

The PushSubscription calls read the first method response without
checking it, so an `error` response listed no devices, and a refused
verify or destroy (revoking another device) was reported as done. Route
every call through `requireMethodResult` and `assertSetResult`; a
destroy the server answers with `notFound` still counts as done.

src/api/__tests__/push.test.ts

@@ -15,9 +15,11 @@ vi.mock('../jmap-client', () => ({
 import { jmapClient } from '../jmap-client';
 import {
   createPushSubscription,
+  destroyPushSubscription,
   listPushSubscriptions,
   startPolling,
   updatePushSubscription,
+  verifyPushSubscription,
 } from '../push';
 
 const mockRequest = jmapClient.request as ReturnType<typeof vi.fn>;
@@ -121,6 +123,44 @@ describe('push operations', () => {
         .rejects.toMatchObject({ type: 'forbidden' });
     });
 
+    it('throws when the verification code is refused', async () => {
+      mockRequest.mockResolvedValue({
+        methodResponses: [[
+          'PushSubscription/set',
+          { notUpdated: { s1: { type: 'invalidProperties', description: 'Verification code does not match.' } } },
+          '0',
+        ]],
+      });
+      await expect(verifyPushSubscription('s1', 'CODE')).rejects.toThrow('Verification code does not match.');
+    });
+
+    it('throws when a destroy is refused', async () => {
+      mockRequest.mockResolvedValue({
+        methodResponses: [['PushSubscription/set', { notDestroyed: { s1: forbidden } }, '0']],
+      });
+      await expect(destroyPushSubscription('s1')).rejects.toMatchObject({ type: 'forbidden' });
+    });
+
+    it('treats destroying a subscription that is already gone as done', async () => {
+      mockRequest.mockResolvedValue({
+        methodResponses: [['PushSubscription/set', { notDestroyed: { s1: { type: 'notFound' } } }, '0']],
+      });
+      await expect(destroyPushSubscription('s1')).resolves.toBeUndefined();
+    });
+
+    it.each([
+      ['list', () => listPushSubscriptions()],
+      ['create', () => createPushSubscription({ deviceClientId: 'd', url: 'https://relay/x', types: ['EmailDelivery'] })],
+      ['update', () => updatePushSubscription('s1', { expires: '2026-10-01T00:00:00Z' })],
+      ['verify', () => verifyPushSubscription('s1', 'CODE')],
+      ['destroy', () => destroyPushSubscription('s1')],
+    ])('%s throws on a method-level error response', async (_name, call) => {
+      mockRequest.mockResolvedValue({
+        methodResponses: [['error', { type: 'serverFail', description: 'Store unavailable' }, '0']],
+      });
+      await expect(call()).rejects.toMatchObject({ name: 'JMAPMethodError', type: 'serverFail' });
+    });
+
     it('resolves when the update is applied', async () => {
       mockRequest.mockResolvedValue({
         methodResponses: [['PushSubscription/set', { updated: { s1: null } }, '0']],

src/api/push.ts

@@ -1,5 +1,5 @@
 import { jmapClient } from './jmap-client';
-import { assertSetResult, JMAPMethodError } from './jmap-result';
+import { assertSetResult, JMAPMethodError, requireMethodResult } from './jmap-result';
 import { CAPABILITIES } from './types';
 import type { EmailPushConfig, PushSubscription, StateChange } from './types';
 
@@ -33,8 +33,8 @@ export async function listPushSubscriptions(): Promise<PushSubscription[]> {
     [['PushSubscription/get', args, '0']],
     pushUsing(withEmailPush),
   );
-  const [, body] = res.methodResponses[0] ?? [];
-  return (body?.list as PushSubscription[]) ?? [];
+  const body = requireMethodResult(res, '0', 'PushSubscription/get');
+  return (body.list as PushSubscription[]) ?? [];
 }
 
 /**
@@ -74,9 +74,9 @@ export async function createPushSubscription(params: {
     ],
     pushUsing(withEmailPush),
   );
-  const [, body] = res.methodResponses[0] ?? [];
+  const body = requireMethodResult(res, '0', 'PushSubscription/set');
   assertSetResult(body, ['new'], 'push subscription');
-  const result = body?.created?.new as { id?: string } | undefined;
+  const result = body.created?.new as { id?: string } | undefined;
   if (!result?.id) {
     throw new Error(`PushSubscription/set create failed: ${JSON.stringify(body)}`);
   }
@@ -107,9 +107,9 @@ export async function updatePushSubscription(
     ],
     pushUsing(withEmailPush),
   );
-  const [, body] = res.methodResponses[0] ?? [];
+  const body = requireMethodResult(res, '0', 'PushSubscription/set');
   assertSetResult(body, [id], 'push subscription');
-  if (body?.updated?.[id] === undefined) {
+  if (body.updated?.[id] === undefined) {
     throw new JMAPMethodError('notUpdated', `PushSubscription/set did not update ${id}`);
   }
 }
@@ -132,19 +132,19 @@ export async function verifyPushSubscription(
     ],
     [CAPABILITIES.CORE],
   );
-  const [, body] = res.methodResponses[0] ?? [];
-  if (body?.notUpdated?.[id]) {
-    throw new Error(
-      `PushSubscription verification failed: ${JSON.stringify(body.notUpdated[id])}`,
-    );
-  }
+  const body = requireMethodResult(res, '0', 'PushSubscription/set');
+  assertSetResult(body, [id], 'push subscription');
 }
 
 export async function destroyPushSubscription(id: string): Promise<void> {
-  await jmapClient.request(
+  const res = await jmapClient.request(
     [['PushSubscription/set', { destroy: [id] }, '0']],
     [CAPABILITIES.CORE],
   );
+  const body = requireMethodResult(res, '0', 'PushSubscription/set');
+  // Already gone is what the caller asked for.
+  if (body.notDestroyed?.[id]?.type === 'notFound') return;
+  assertSetResult(body, [id], 'push subscription');
 }
 
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