Add payment cancellation support

payments/__init__.py

@@ -35,6 +35,7 @@ class PaymentStatus:
     REFUNDED = "refunded"
     ERROR = "error"
     INPUT = "input"
+    CANCELLED = "cancelled"
 
     CHOICES = [
         (WAITING, pgettext_lazy("payment status", "Waiting for confirmation")),
@@ -44,6 +45,7 @@ class PaymentStatus:
         (REFUNDED, pgettext_lazy("payment status", "Refunded")),
         (ERROR, pgettext_lazy("payment status", "Error")),
         (INPUT, pgettext_lazy("payment status", "Input")),
+        (CANCELLED, pgettext_lazy("payment status", "Cancelled")),
     ]
 
 

payments/core.py

@@ -152,6 +152,9 @@ def release(self, payment):
     def refund(self, payment, amount=None):
         raise NotImplementedError
 
+    def cancel(self, payment):
+        raise NotImplementedError
+
 
 PROVIDER_CACHE = {}
 

payments/dummy/__init__.py

@@ -76,3 +76,6 @@ def release(self, payment):
 
     def refund(self, payment, amount=None):
         return amount or 0
+
+    def cancel(self, payment):
+        return None

payments/dummy/test_dummy.py

@@ -171,3 +171,48 @@ def test_provider_switches_payment_status_on_get_form(payment):
     provider = DummyProvider()
     provider.get_form(payment, data={})
     assert payment.status == PaymentStatus.INPUT
+
+
+def test_cancel_waiting_payment(payment):
+    provider = DummyProvider()
+    payment.status = PaymentStatus.WAITING
+    provider.cancel(payment)
+
+
+def test_cancel_input_payment(payment):
+    provider = DummyProvider()
+    payment.status = PaymentStatus.INPUT
+    provider.cancel(payment)
+
+
+def test_process_data_sets_cancelled_via_verification_result(payment):
+    provider = DummyProvider()
+    payment.status = PaymentStatus.WAITING
+    request = MagicMock()
+    request.GET = {"verification_result": PaymentStatus.CANCELLED}
+    response = provider.process_data(payment, request)
+    assert payment.status == PaymentStatus.CANCELLED
+    assert response.status_code == 302
+    assert response["location"] == payment.get_failure_url()
+
+
+def test_cancelled_payment_redirects_to_failure(payment):
+    provider = DummyProvider()
+    payment.status = PaymentStatus.CANCELLED
+    request = MagicMock()
+    request.GET = {}
+    response = provider.process_data(payment, request)
+    assert response["location"] == payment.get_failure_url()
+
+
+def test_get_form_with_cancelled_status(payment):
+    provider = DummyProvider()
+    data = {
+        "status": PaymentStatus.CANCELLED,
+        "fraud_status": FraudStatus.UNKNOWN,
+        "gateway_response": "3ds-disabled",
+        "verification_result": "",
+    }
+    with pytest.raises(RedirectNeeded) as exc:
+        provider.get_form(payment, data)
+    assert exc.value.args[0] == payment.get_failure_url()

payments/models.py

@@ -239,6 +239,21 @@ def refund(self, amount=None):
             self.change_status(PaymentStatus.REFUNDED)
         self.save()
 
+    def cancel(self):
+        """Cancel a payment.
+
+        Only payments that have not been processed can be cancelled.
+        For pre-authorized payments, use release() instead.
+        For confirmed payments, use refund() instead.
+
+        Note that not all providers support this method.
+        """
+        if self.status not in [PaymentStatus.WAITING, PaymentStatus.INPUT]:
+            raise ValueError("Only waiting or input payments can be cancelled.")
+        provider = provider_factory(self.variant, self)
+        provider.cancel(self)
+        self.change_status(PaymentStatus.CANCELLED)
+
     @property
     def attrs(self):
         """A JSON-serialised wrapper around `extra_data`.

payments/test_core.py

@@ -268,3 +268,48 @@ def test_amex():
         "amex",
         "American Express",
     )
+
+
+def test_cancel_with_wrong_status_confirmed():
+    payment = Payment(variant="default", status=PaymentStatus.CONFIRMED)
+    with pytest.raises(
+        ValueError,
+        match="Only waiting or input payments can be cancelled\\.",
+    ):
+        payment.cancel()
+
+
+def test_cancel_with_wrong_status_preauth():
+    payment = Payment(variant="default", status=PaymentStatus.PREAUTH)
+    with pytest.raises(
+        ValueError,
+        match="Only waiting or input payments can be cancelled\\.",
+    ):
+        payment.cancel()
+
+
+def test_cancel_with_wrong_status_refunded():
+    payment = Payment(variant="default", status=PaymentStatus.REFUNDED)
+    with pytest.raises(
+        ValueError,
+        match="Only waiting or input payments can be cancelled\\.",
+    ):
+        payment.cancel()
+
+
+@patch("payments.dummy.DummyProvider.cancel")
+def test_cancel_waiting_payment_successfully(mocked_cancel_method):
+    with patch.object(BasePayment, "save"):
+        payment = Payment(variant="default", status=PaymentStatus.WAITING)
+        payment.cancel()
+        assert payment.status == PaymentStatus.CANCELLED
+    assert mocked_cancel_method.call_count == 1
+
+
+@patch("payments.dummy.DummyProvider.cancel")
+def test_cancel_input_payment_successfully(mocked_cancel_method):
+    with patch.object(BasePayment, "save"):
+        payment = Payment(variant="default", status=PaymentStatus.INPUT)
+        payment.cancel()
+        assert payment.status == PaymentStatus.CANCELLED
+    assert mocked_cancel_method.call_count == 1

testapp/testapp/testmain/migrations/0003_alter_payment_status.py

@@ -0,0 +1,32 @@
+# Generated by Django 5.2.8 on 2025-11-17 18:12
+from __future__ import annotations
+
+from django.db import migrations
+from django.db import models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("testmain", "0002_payment_billing_phone"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="payment",
+            name="status",
+            field=models.CharField(
+                choices=[
+                    ("waiting", "Waiting for confirmation"),
+                    ("preauth", "Pre-authorized"),
+                    ("confirmed", "Confirmed"),
+                    ("rejected", "Rejected"),
+                    ("refunded", "Refunded"),
+                    ("error", "Error"),
+                    ("input", "Input"),
+                    ("cancelled", "Cancelled"),
+                ],
+                default="waiting",
+                max_length=10,
+            ),
+        ),
+    ]