TestCreditCardDetection Class — langchain Architecture

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_pii.py lines 61–97

class TestCreditCardDetection:
    """Test credit card detection with Luhn validation."""

    def test_detect_valid_credit_card(self) -> None:
        # Valid Visa test number
        content = "Card: 4532015112830366"
        matches = detect_credit_card(content)

        assert len(matches) == 1
        assert matches[0]["type"] == "credit_card"
        assert matches[0]["value"] == "4532015112830366"

    def test_detect_credit_card_with_spaces(self) -> None:
        # Valid Mastercard test number
        # Add spaces
        spaced_content = "Card: 5425 2334 3010 9903"
        matches = detect_credit_card(spaced_content)

        assert len(matches) == 1
        assert "5425 2334 3010 9903" in matches[0]["value"]

    def test_detect_credit_card_with_dashes(self) -> None:
        content = "Card: 4532-0151-1283-0366"
        matches = detect_credit_card(content)

        assert len(matches) == 1

    def test_invalid_luhn_not_detected(self) -> None:
        # Invalid Luhn checksum
        content = "Card: 1234567890123456"
        matches = detect_credit_card(content)
        assert len(matches) == 0

    def test_no_credit_card(self) -> None:
        content = "No cards here."
        matches = detect_credit_card(content)
        assert len(matches) == 0