The cardnum function serves as a vital component within the financial suite of the mock-jutsu library, specifically engineered to produce realistic, synthetic credit card identifiers for development environments. When building sophisticated fintech applications, the requirement for high-quality mock data is essential to ensure that payment processing workflows are robust and reliable. This utility generates sixteen-digit sequences that mirror the formatting of major global card issuers, allowing developers to populate their systems with data that looks and behaves like the real thing without compromising security or privacy.
A standout feature of this function is its strict adherence to the Luhn algorithm, the checksum standard used worldwide for validating various identification numbers. By generating numbers that are mathematically valid according to this algorithm, mock-jutsu ensures that the test data will pass the initial validation layers of most web forms and payment gateways. This technical precision is invaluable for QA teams, as it prevents automated tests from failing due to simple formatting errors, thereby allowing for more comprehensive end-to-end testing of the entire transaction lifecycle without the need for actual financial records.
Flexibility is a core tenet of the mock-jutsu philosophy, and the cardnum tool is accessible through multiple interfaces to suit any project requirement. Developers can generate a quick sample via the CLI using "mockjutsu generate cardnum", or integrate it directly into their Python test suites with a simple jutsu.generate('cardnum') call. For those conducting load testing or stress testing, the JMeter function ${__mockjutsu(cardnum,)} provides a seamless way to inject valid-format card numbers into high-concurrency scripts, ensuring that performance benchmarks remain accurate and realistic across various testing platforms.
Beyond simple data generation, using cardnum significantly enhances a team's ability to handle complex testing scenarios, such as verifying database schema integrity or testing the error-handling logic of third-party API integrations. By prioritising the use of validated mock data over real financial information, organisations can maintain a high standard of data privacy and regulatory compliance. Ultimately, this function empowers developers to build safer, more reliable financial software by providing the exact tools needed to simulate real-world data conditions within a controlled and secure testing environment.
mockjutsu generate cardnum --network visamockjutsu bulk cardnum --count 10mockjutsu export cardnum --count 10 --format jsonmockjutsu export cardnum --count 10 --format csvmockjutsu export cardnum --count 10 --format sql# --mask: regulation-compliant output (PCI DSS / GDPR / KVKK)mockjutsu generate cardnum --maskmockjutsu bulk cardnum --count 5 --maskfrom mockjutsu import jutsujutsu.generate('cardnum')jutsu.bulk('cardnum', count=10)jutsu.template(['cardnum'], count=5)# with --network parameterjutsu.generate('cardnum', network='visa')# mask=True: regulation-compliant outputjutsu.generate('cardnum', mask=True)jutsu.bulk('cardnum', count=5, mask=True)${__mockjutsu_financial(cardnum)}${__mockjutsu_financial(cardnum:visa)}# JMeter Function: __mockjutsu_financial# Parameter 1: cardnum OR cardnum:# Qualifier values: visa|mc|amex|troy|mir|jcb|discover|unionpay|maestro# Parameter 2: (not required for this function)# Add 'mask' keyword to get a regulation-compliant masked value${__mockjutsu_financial(cardnum,mask)}GET /generate/cardnum# → {"type":"cardnum","result":"...","status":"ok"}GET /bulk/cardnum?count=10POST /template {"types":["cardnum"],"count":1}# mask=true: regulation-compliant outputGET /generate/cardnum?mask=trueGET /bulk/cardnum?count=5&mask=true| Parameter | Values | Description |
|---|---|---|
| --network | visa|mc|amex|troy|mir|jcb|discover|unionpay|maestro | Card network |
| --mask | true | false | Return a regulation-compliant masked value (PCI DSS, GDPR, KVKK…) |