test(billing): make fusion_centralize_billing suite hermetic (green baseline)

- test_usage / test_webhook setUp: get-or-create the cpu_seconds metric and
  nexacloud service so the suite no longer collides with existing rows.
- test_invoice_ledger: add _fc_ensure_ca_billing_env (activate CAD + a 13%
  sale tax matching _fc_tax_for) so the ledger tests pass on a clean DB.

Canonical test DB: a FRESH db with l10n_ca installed (a prod clone collides
on fixed-code fixtures across 5 test files). Full suite now exits 0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

fusion_centralize_billing/tests/test_invoice_ledger.py

@@ -18,11 +18,26 @@ def _inv_fixture():
     }]
 
 
+def _fc_ensure_ca_billing_env(env):
+    """Prod (`nexamain`) is a fully-configured Canadian company; a bare test DB is not.
+    Give it the two things the ledger needs: an active CAD currency and a 13% sale tax
+    matching invoice.ledger.wizard._fc_tax_for (type_tax_use=sale, percent, amount=13)."""
+    cad = env.ref('base.CAD')
+    if not cad.active:
+        cad.sudo().write({'active': True})
+    Tax = env['account.tax'].sudo()
+    if not Tax.search([('type_tax_use', '=', 'sale'),
+                       ('amount_type', '=', 'percent'), ('amount', '=', 13.0)], limit=1):
+        Tax.create({'name': 'HST 13%', 'type_tax_use': 'sale',
+                    'amount_type': 'percent', 'amount': 13.0})
+
+
 @tagged('post_install', '-at_install')
 class TestLedgerFamily(TransactionCase):
 
     def setUp(self):
         super().setUp()
+        _fc_ensure_ca_billing_env(self.env)
         self.W = self.env['fusion.billing.invoice.ledger.wizard'].sudo()
 
     def test_family_classification(self):
@@ -47,6 +62,7 @@ class TestLedgerTax(TransactionCase):
 
     def setUp(self):
         super().setUp()
+        _fc_ensure_ca_billing_env(self.env)
         self.W = self.env['fusion.billing.invoice.ledger.wizard'].sudo()
 
     def test_tax_for_13pct_is_a_13_percent_sale_tax(self):
@@ -68,6 +84,7 @@ class TestLedgerIngest(TransactionCase):
 
     def setUp(self):
         super().setUp()
+        _fc_ensure_ca_billing_env(self.env)
         self.W = self.env['fusion.billing.invoice.ledger.wizard'].sudo()
         self.Move = self.env['account.move']
 
@@ -174,6 +191,7 @@ class TestLedgerVerifiedSync(TransactionCase):
 
     def setUp(self):
         super().setUp()
+        _fc_ensure_ca_billing_env(self.env)
         self.W = self.env['fusion.billing.invoice.ledger.wizard'].sudo()
         self.Move = self.env['account.move']
         ICP = self.env['ir.config_parameter'].sudo()

fusion_centralize_billing/tests/test_usage.py

@@ -9,7 +9,8 @@ class TestRatingCron(TransactionCase):
 
     def setUp(self):
         super().setUp()
-        self.metric = self.env['fusion.billing.metric'].sudo().create(
+        Metric = self.env['fusion.billing.metric'].sudo()
+        self.metric = Metric.search([('code', '=', 'cpu_seconds')], limit=1) or Metric.create(
             {'name': 'CPU seconds', 'code': 'cpu_seconds', 'aggregation': 'sum'})
         self.plan_a = self.env['sale.subscription.plan'].sudo().create(
             {'name': 'Plan A', 'billing_period_value': 1, 'billing_period_unit': 'month'})
@@ -67,7 +68,8 @@ class TestUsageIngestion(TransactionCase):
 
     def setUp(self):
         super().setUp()
-        self.metric = self.env['fusion.billing.metric'].sudo().create(
+        Metric = self.env['fusion.billing.metric'].sudo()
+        self.metric = Metric.search([('code', '=', 'cpu_seconds')], limit=1) or Metric.create(
             {'name': 'CPU seconds', 'code': 'cpu_seconds', 'aggregation': 'sum'})
         self.plan = self.env['sale.subscription.plan'].sudo().create(
             {'name': 'Monthly', 'billing_period_value': 1, 'billing_period_unit': 'month'})

fusion_centralize_billing/tests/test_webhook.py

@@ -13,11 +13,17 @@ class TestWebhookEngine(TransactionCase):
 
     def setUp(self):
         super().setUp()
-        self.service = self.env['fusion.billing.service'].sudo().create({
+        Service = self.env['fusion.billing.service'].sudo()
+        vals = {
             'name': 'NexaCloud', 'code': 'nexacloud',
             'webhook_url': 'https://api.vps.nexasystems.ca/billing/webhook',
             'webhook_secret': 'whsec_test',
-        })
+        }
+        self.service = Service.search([('code', '=', 'nexacloud')], limit=1)
+        if self.service:
+            self.service.write(vals)
+        else:
+            self.service = Service.create(vals)
         self.Webhook = self.env['fusion.billing.webhook'].sudo()
 
     def test_enqueue_signs_payload(self):