fix(desktop): resolve native notification action indexes

Adapted from https://github.com/NousResearch/hermes-agent/pull/51893 (a70b0991b2d72796479d63532ccf0fac15b17ba0).

Co-authored-by: brooklyn! <brooklyn.bb.nicholson@gmail.com>

apps/desktop/electron/notification-actions.test.ts

@@ -0,0 +1,22 @@
+import assert from 'node:assert/strict'
+
+import { test } from 'vitest'
+
+import { resolveNotificationAction } from './notification-actions'
+
+const actions = [
+  { id: 'approve', text: 'Approve' },
+  { id: 'reject', text: 'Reject' }
+]
+
+test('prefers Electron event details and supports the legacy positional index', () => {
+  assert.deepEqual(resolveNotificationAction(actions, { actionIndex: 1 }, undefined), actions[1])
+  assert.deepEqual(resolveNotificationAction(actions, {}, 0), actions[0])
+  assert.deepEqual(resolveNotificationAction(actions, { actionIndex: 1 }, 0), actions[1])
+})
+
+test('ignores missing and out-of-range action indexes', () => {
+  assert.equal(resolveNotificationAction(actions, {}, undefined), null)
+  assert.equal(resolveNotificationAction(actions, { actionIndex: -1 }, undefined), null)
+  assert.equal(resolveNotificationAction(actions, { actionIndex: 2 }, undefined), null)
+})

apps/desktop/electron/notification-actions.ts

@@ -0,0 +1,29 @@
+function isActionIndex(value: unknown): value is number {
+  return typeof value === 'number' && Number.isInteger(value)
+}
+
+function notificationActionIndex(actionEvent: unknown, legacyIndex: unknown): number | null {
+  if (actionEvent && typeof actionEvent === 'object' && 'actionIndex' in actionEvent) {
+    const { actionIndex } = actionEvent as { actionIndex?: unknown }
+
+    if (isActionIndex(actionIndex)) {
+      return actionIndex
+    }
+  }
+
+  return isActionIndex(legacyIndex) ? legacyIndex : null
+}
+
+export function resolveNotificationAction<T>(
+  actions: readonly T[],
+  actionEvent: unknown,
+  legacyIndex: unknown
+): T | null {
+  const index = notificationActionIndex(actionEvent, legacyIndex)
+
+  if (index === null || index < 0 || index >= actions.length) {
+    return null
+  }
+
+  return actions[index] ?? null
+}