test writer pro

I have analyzed payment_service.py and your existing test suite.

Detected

pytest with fixtures from conftest.py, using pytest-mock for boundaries and factory_boy for data generation. Naming convention follows test_<behavior>.

Test Suite for PaymentService

import pytest
from app.services.payment_service import PaymentService
from app.exceptions import PaymentError

@pytest.mark.parametrize("amount, expected_status", [
    (100.0, "success"),
    (50.5, "success"),
])
def test_process_refund_full_and_partial(mocker, db_session, user_factory, amount, expected_status):
    """
    Ensures both full and partial refunds update the transaction state correctly.
    """
    # Arrange
    user = user_factory()
    service = PaymentService(db_session)
    mock_gateway = mocker.patch("app.services.payment_service.StripeGateway.refund")
    mock_gateway.return_value = {"status": "succeeded"}

    # Act
    result = service.process_refund(user_id=user.id, amount=amount)

    # Assert
    assert result.status == expected_status
    assert result.amount == amount
    mock_gateway.assert_called_once()

def test_process_refund_fails_with_expired_token(mocker, db_session, user_factory):
    """
    Validates that expired tokens propagate a PaymentError rather than failing silently.
    """
    # Arrange
    user = user_factory()
    service = PaymentService(db_session)
    mocker.patch("app.services.payment_service.check_token", return_value=False)

    # Act & Assert
    with pytest.raises(PaymentError, match="Token expired"):
        service.process_refund(user_id=user.id, amount=10.0)

def test_process_refund_idempotency(mocker, db_session, user_factory):
    """
    Verifies that duplicate refund requests for the same transaction ID do not trigger multiple API calls.
    """
    # Arrange
    user = user_factory()
    service = PaymentService(db_session)
    mock_gateway = mocker.patch("app.services.payment_service.StripeGateway.refund")
    
    # Act
    service.process_refund(user_id=user.id, amount=10.0, idempotency_key="test_key")
    service.process_refund(user_id=user.id, amount=10.0, idempotency_key="test_key")

    # Assert
    assert mock_gateway.call_count == 1

Next steps

1. Run the new tests: pytest tests/test_payment_service.py -v
2. Review the PaymentError handling; the current implementation logs the error but does not alert Sentry.
3. Verify if the idempotency key should expire after 24 hours.