feat(billing): outbound webhook engine (HMAC + retry/backoff)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

fusion_centralize_billing/tests/test_webhook.py

@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+import hashlib
+import hmac
+import json
+from unittest.mock import patch
+
+from odoo.tests.common import TransactionCase, tagged
+
+
+@tagged('post_install', '-at_install')
+class TestWebhookEngine(TransactionCase):
+
+    def setUp(self):
+        super().setUp()
+        self.service = self.env['fusion.billing.service'].sudo().create({
+            'name': 'NexaCloud', 'code': 'nexacloud',
+            'webhook_url': 'https://api.vps.nexasystems.ca/billing/webhook',
+            'webhook_secret': 'whsec_test',
+        })
+        self.Webhook = self.env['fusion.billing.webhook'].sudo()
+
+    def test_enqueue_signs_payload(self):
+        wh = self.Webhook._enqueue(self.service, 'invoice.payment_failed', {'invoice': 'INV-1'})
+        self.assertEqual(wh.state, 'pending')
+        body = json.dumps({'invoice': 'INV-1'}, sort_keys=True, separators=(',', ':'))
+        expected = hmac.new(b'whsec_test', body.encode(), hashlib.sha256).hexdigest()
+        self.assertEqual(wh.signature, expected)
+
+    def test_dispatch_marks_sent_on_2xx(self):
+        wh = self.Webhook._enqueue(self.service, 'invoice.paid', {'invoice': 'INV-2'})
+
+        class _Resp:
+            status_code = 200
+            text = 'ok'
+
+        with patch('odoo.addons.fusion_centralize_billing.models.webhook.requests.post',
+                   return_value=_Resp()) as mock_post:
+            self.Webhook._cron_dispatch()
+            self.assertTrue(mock_post.called)
+        self.assertEqual(wh.state, 'sent')
+
+    def test_dispatch_retries_then_deadletters(self):
+        wh = self.Webhook._enqueue(self.service, 'invoice.paid', {'invoice': 'INV-3'})
+        wh.write({'attempts': 7})  # already past max
+
+        class _Resp:
+            status_code = 500
+            text = 'err'
+
+        with patch('odoo.addons.fusion_centralize_billing.models.webhook.requests.post',
+                   return_value=_Resp()):
+            self.Webhook._cron_dispatch()
+        self.assertEqual(wh.state, 'dead')