Build Input Validation and Sanitization Module

[memplethee-lab]

Overview

Create a comprehensive validation and sanitization module to ensure all API inputs are validated, sanitized, and conform to expected formats before processing.

Direction

This module should provide:

• Schema validation for request payloads
• Custom validation rules and decorators
• Input sanitization to prevent injection attacks
• Type coercion and normalization
• Comprehensive error messages for validation failures
• Support for nested object validation
• Reusable validation schemas

Implementation Details

The validation module should integrate with the request pipeline and use a schema validation library (class-validator or similar). It should provide both automatic validation through decorators and manual validation functions.

Acceptance Criteria

• Request validation middleware enforces schema validation on all endpoints
• Validation errors return 400 Bad Request with detailed error messages
• Custom validators can be easily defined and composed
• Input sanitization prevents XSS and SQL injection attacks
• All string inputs are trimmed and normalized
• Email validation follows RFC 5322 standards
• Nested object validation works recursively
• Validation rules are well documented with examples
• Unit tests cover all validation scenarios with >85% coverage

[Scepter00]

Hi! I'd like to work on this issue.

I have experience building secure backend APIs and implementing validation layers that improve both application security and developer experience. This issue is particularly valuable because a centralized validation and sanitization module establishes a strong foundation for the entire API.

My approach will be to build a reusable validation framework that integrates seamlessly into the request pipeline, using a schema based validation library to support automatic validation through decorators as well as manual validation where needed. I'll implement input sanitization, type coercion, normalization, nested object validation, and composable custom validators while ensuring validation failures produce clear, consistent, and actionable error responses.

I'll also ensure common security concerns are addressed by trimming and normalizing string inputs, validating email addresses against the appropriate standard, and sanitizing user input to reduce the risk of XSS and injection attacks. The implementation will be designed to make validation rules easy to reuse across endpoints and straightforward to extend as the project grows.

To validate the solution, I'll write comprehensive unit tests covering successful validation, failure cases, nested objects, custom validators, sanitization behavior, and edge cases while targeting the required test coverage. In the PR, I'll document the validation architecture, provide usage examples, and explain how new validation rules can be added.

I'd be happy to take ownership of this issue and ensure the implementation meets all of the acceptance criteria.

[JuanVP2]

I'd like to work on this issue. I will implement a robust requireNonNegativeNumber validation utility function inside utils/validation.ts that safely permits zero values while strictly rejecting negative metrics, complete with matching unit tests.

[grantfox-oss]

🦊 GrantFox — @JuanVP2 has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #106)
2. Your PR will be reviewed by the SourceXXL maintainers

Good luck! Track your progress on GrantFox.