Yes, including sample or test code in a managed package can cause a security review to fail. To manage development and sample code effectively and avoid security review issues, follow these guidelines:
1. **Remove Sample Code Before Submission**: It's recommended to remove any sample code before submission, as it may be flagged as a security concern.
2. **Avoid Using Sample Code in Production**: Use sample code only for learning purposes. Write your own production code to ensure it meets security standards and avoids vulnerabilities.
3. **Follow Secure Coding Practices**: Adhere to Salesforce's secure coding guidelines, avoiding risky practices like direct DOM manipulation.
4. **Test and Scan Code Regularly**: Use tools like Salesforce Code Analyzer and Source Code Scanner to identify and address vulnerabilities.
5. **Document False Positives**: If there are false positives, document them thoroughly to explain why they are non-exploitable or irrelevant.
6. **Avoid Common Violations**: Do not include dynamically loaded third-party JavaScript or CSS files from external sources. Use static resources instead and ensure secure communication protocols like HTTPS.
7. **Manually Test the Solution**: Perform manual testing to catch vulnerabilities that automated tools might miss.
8. **Prepare for Security Review**: Ensure your solution is secure, Lightning Ready, and thoroughly tested. Submit all required materials, including scan reports and false-positive documentation, through the AppExchange Partner Console.
These practices will help minimize security risks and improve your chances of passing the security review.