Not using placeholders should be an automatic fail of any code review. Period. Without placeholders the risk is way, way too high. A single mistake can be the

Not using placeholders should be an automatic fail of any code review. Period. Without placeholders the risk is way, way too high. A single mistake can be the end of your entire application if not career. Don't think "Oh, this is just test code, I'll fix it later" and leave a vulnerability in your application. Always write using placeholders. No exceptions.