add payment_link and banks

tests/test_payment_concurrency.py

@@ -0,0 +1,49 @@
+"""Run against an isolated PostgreSQL test DB; SQLite cannot prove row-lock semantics.
+USE_SQLITE=false POSTGRES_* ... pytest tests/test_payment_concurrency.py
+Never point POSTGRES_DB at a production database.
+"""
+from concurrent.futures import ThreadPoolExecutor
+from threading import Barrier
+import pytest
+from django.db import connection, close_old_connections
+from django.core.exceptions import ValidationError
+from apps.accounts.models import User
+from apps.notifications.models import NotificationJob
+from apps.payments import services
+from apps.payments.models import PaymentReceipt, ReceiptDecision
+from tests.test_payments import case, submit
+
+pytestmark = [pytest.mark.django_db(transaction=True),
+              pytest.mark.skipif(connection.vendor != 'postgresql', reason='Requires PostgreSQL row locks')]
+
+
+@pytest.mark.parametrize('actors,actions,final', [
+    (('first','second'), ('APPROVE','APPROVE'), 'APPROVED'),
+    (('first','first'), ('APPROVE','APPROVE'), 'PARTIAL'),
+    (('first','second'), ('APPROVE','REJECT'), 'REJECTED'),
+    (('first','senior'), ('APPROVE','SENIOR_APPROVE'), 'APPROVED'),
+])
+def test_concurrent_decisions_have_one_consistent_final_result(case, actors, actions, final):
+    receipt = submit(case)
+    barrier = Barrier(2)
+    def decide(index):
+        close_old_connections()
+        try:
+            actor = User.objects.get(pk=case[actors[index]].pk)
+            barrier.wait(timeout=10)
+            try:
+                services.decide_receipt(actor, receipt.public_id, 1, actions[index], 'بررسی پرداخت')
+                return 'recorded'
+            except ValidationError:
+                return 'already finalized'
+        finally:
+            connection.close()
+    with ThreadPoolExecutor(max_workers=2) as pool:
+        outcomes = list(pool.map(decide, range(2)))
+    receipt.refresh_from_db()
+    assert receipt.status == final
+    assert receipt.revisions.get().cycle.status == final
+    assert outcomes.count('recorded') >= 1
+    votes = ReceiptDecision.objects.filter(cycle__revision__receipt=receipt)
+    assert votes.count() == (1 if actors[0] == actors[1] else outcomes.count('recorded'))
+    assert NotificationJob.objects.filter(event_type='PAYMENT_RECEIPT_APPROVED').count() == (1 if final == 'APPROVED' else 0)