test(payment): add unit tests for promo code currency and minimum amount handling (#23300, #23299)

Author: Dimank92

backend/tests/unit/test_payment_promo_currency_minimum_amount.py

@@ -0,0 +1,179 @@
+"""Unit tests for promo code minimum_amount and multi-currency / trial resilience.
+
+Regression tests for:
+- Issue #23300: Unlimited first-year promo code rejected with 'minimum amount' in GBP / trial checkout
+- Issue #23299: Unlimited membership promo codes carry a USD $269 minimum, rejected for customers paying in other currencies
+"""
+
+import sys
+from types import SimpleNamespace
+from unittest.mock import MagicMock, patch
+import pytest
+from fastapi import HTTPException
+
+import stripe
+from models.users import PlanType, Subscription, SubscriptionStatus
+from utils.subscription import get_plan_limits
+import utils.stripe as stripe_utils
+from routers.payment import (
+    create_checkout_session_endpoint,
+    upgrade_subscription_endpoint,
+    CreateCheckoutRequest,
+    UpgradeSubscriptionRequest,
+)
+
+
+def test_checkout_suppresses_trial_when_promo_provided():
+    """When a promo code is provided in checkout, trial_days is omitted to prevent $0 minimum_amount conflict."""
+    captured = {}
+
+    def mock_create_session(uid, price_id, idempotency_key, customer_id=None, promotion_code_id=None, trial_period_days=None):
+        captured['promotion_code_id'] = promotion_code_id
+        captured['trial_period_days'] = trial_period_days
+        return SimpleNamespace(url='https://checkout.stripe.com/pay/cs_test', id='cs_test')
+
+    promo_mock = MagicMock()
+    promo_mock.id = 'promo_unlimited_year'
+    promo_list_mock = MagicMock(data=[promo_mock])
+
+    with (
+        patch('routers.payment._validate_price_id'),
+        patch('routers.payment.subscription_utils.can_user_make_payment', return_value=(True, '')),
+        patch('routers.payment.stripe.PromotionCode.list', return_value=promo_list_mock),
+        patch('routers.payment._try_reactivate_subscription', return_value=None),
+        patch('routers.payment.users_db.get_stripe_customer_id', return_value=None),
+        patch('routers.payment.stripe_utils.create_subscription_checkout_session', side_effect=mock_create_session),
+    ):
+        req = CreateCheckoutRequest(price_id='price_unlimited_annual', promotion_code='OMI-4FHY-W6SR', trial_days=7)
+        resp = create_checkout_session_endpoint(req, uid='uid_test')
+
+        assert resp['session_id'] == 'cs_test'
+        assert captured['promotion_code_id'] == 'promo_unlimited_year'
+        assert captured['trial_period_days'] is None
+
+
+def test_create_subscription_checkout_session_disables_adaptive_pricing_and_trial():
+    """Verify create_subscription_checkout_session omits trial and disables adaptive pricing when promo provided."""
+    with patch('utils.stripe.stripe.checkout.Session.create') as mock_session_create:
+        mock_session_create.return_value = SimpleNamespace(url='https://checkout.stripe.com/test', id='cs_123')
+
+        stripe_utils.create_subscription_checkout_session(
+            uid='uid_1',
+            price_id='price_unlimited',
+            idempotency_key='idem_1',
+            promotion_code_id='promo_123',
+            trial_period_days=7,
+        )
+
+        mock_session_create.assert_called_once()
+        params = mock_session_create.call_args[1]
+        assert 'trial_period_days' not in params.get('subscription_data', {})
+        assert params.get('discounts') == [{'promotion_code': 'promo_123'}]
+        assert params.get('adaptive_pricing') == {'enabled': False}
+
+
+def test_create_subscription_checkout_session_minimum_amount_fallback_to_coupon():
+    """If Stripe rejects Session.create with minimum amount error, fallback to coupon discount."""
+    min_amount_error = stripe.error.InvalidRequestError(
+        message="This code is valid, but your order doesn't meet the minimum amount.",
+        param="discounts",
+    )
+
+    promo_obj = MagicMock()
+    promo_obj.coupon.id = 'coup_100_percent'
+
+    with (
+        patch('utils.stripe.stripe.checkout.Session.create', side_effect=[min_amount_error, SimpleNamespace(url='https://checkout', id='cs_ok')]) as mock_session_create,
+        patch('utils.stripe.stripe.PromotionCode.retrieve', return_value=promo_obj) as mock_retrieve,
+    ):
+        session = stripe_utils.create_subscription_checkout_session(
+            uid='uid_1',
+            price_id='price_unlimited',
+            idempotency_key='idem_1',
+            promotion_code_id='promo_min_error',
+        )
+
+        assert session is not None
+        assert session.id == 'cs_ok'
+        assert mock_session_create.call_count == 2
+        retry_params = mock_session_create.call_args[1]
+        assert retry_params['discounts'] == [{'coupon': 'coup_100_percent'}]
+        assert 'adaptive_pricing' not in retry_params
+
+
+def test_upgrade_subscription_endpoint_minimum_amount_fallback_to_coupon():
+    """If Stripe Subscription.modify fails with minimum_amount in EUR/GBP, fallback to coupon and deactivate single-use code."""
+    uid = 'test_user_eur'
+    current_sub = Subscription(
+        plan=PlanType.plus,
+        status=SubscriptionStatus.active,
+        current_period_start=1000,
+        current_period_end=2000,
+        stripe_subscription_id='sub_eur_1',
+    )
+
+    mock_stripe_sub = MagicMock()
+    mock_stripe_sub.to_dict.return_value = {
+        'id': 'sub_eur_1',
+        'cancel_at_period_end': False,
+        'items': {'data': [{'id': 'si_1', 'price': {'id': 'price_plus_monthly'}}]},
+        'current_period_start': 1000,
+        'current_period_end': 2000,
+    }
+
+    target_price_mock = MagicMock()
+    target_price_mock.recurring.interval = 'year'
+
+    min_amount_error = stripe.error.InvalidRequestError(
+        message="The promotion code's minimum amount (269.00 USD) was not met. The invoice total was 249.00 EUR.",
+        param="discounts",
+    )
+
+    promo_obj = MagicMock()
+    promo_obj.id = 'promo_skypilot_1'
+    promo_obj.max_redemptions = 1
+    promo_obj.coupon.id = 'coup_unlimited_year'
+
+    updated_sub_dict = {
+        'id': 'sub_eur_1',
+        'status': 'active',
+        'current_period_start': 2000,
+        'current_period_end': 2000 + 86400 * 365,
+        'items': {'data': [{'id': 'si_1', 'price': {'id': 'price_unlimited_annual'}}]},
+    }
+    mock_updated_sub = MagicMock()
+    mock_updated_sub.to_dict.return_value = updated_sub_dict
+
+    with (
+        patch('routers.payment._validate_price_id'),
+        patch('routers.payment.get_basic_plan_limits', side_effect=lambda: get_plan_limits(PlanType.basic)),
+        patch('routers.payment.get_plan_limits', side_effect=get_plan_limits),
+        patch('routers.payment.users_db.get_user_subscription', return_value=current_sub),
+        patch('routers.payment.stripe.Subscription.retrieve', return_value=mock_stripe_sub),
+        patch('routers.payment.get_plan_type_from_price_id', side_effect=lambda pid: PlanType.unlimited if 'unlimited' in pid else PlanType.plus),
+        patch('routers.payment.stripe.Price.retrieve', return_value=target_price_mock),
+        patch('routers.payment.stripe.PromotionCode.list', return_value=MagicMock(data=[promo_obj])),
+        patch('routers.payment.stripe.PromotionCode.retrieve', return_value=promo_obj),
+        patch('routers.payment.stripe.PromotionCode.modify') as mock_promo_modify,
+        patch('routers.payment._release_attached_schedules'),
+        patch('routers.payment.stripe.Subscription.modify', side_effect=[min_amount_error, mock_updated_sub]) as mock_sub_modify,
+        patch('routers.payment.users_db.update_user_subscription') as mock_update_db,
+        patch('routers.payment.conversations_db.unlock_all_conversations'),
+        patch('routers.payment.memories_db.unlock_all_memories'),
+        patch('routers.payment.action_items_db.unlock_all_action_items'),
+        patch('routers.payment.clear_fair_use_on_upgrade'),
+        patch('routers.payment.set_credits_invalidation_signal'),
+        patch('routers.payment.clear_trial_paywall_cache'),
+        patch('routers.payment.funded_processing_enabled', return_value=False),
+    ):
+        req = UpgradeSubscriptionRequest(price_id='price_unlimited_annual', promotion_code='OMI-EUR-PROMO')
+        resp = upgrade_subscription_endpoint(req, uid=uid)
+
+        assert resp['status'] == 'success'
+        assert mock_sub_modify.call_count == 2
+        # Verify second call used coupon fallback
+        retry_modify_call = mock_sub_modify.call_args_list[1][1]
+        assert retry_modify_call['discounts'] == [{'coupon': 'coup_unlimited_year'}]
+        # Verify single use promo code was deactivated
+        mock_promo_modify.assert_called_once_with('promo_skypilot_1', active=False)
+        mock_update_db.assert_called_once()