Sync get_all_categories with validate_invoice_category allow-list

[Baskarayelu]

Description

Ensure every returned category is valid for upload and updates; test drift detection.

Requirements and context

• Must be secure, tested, and documented
• Should be efficient and easy to review
• Align with existing Soroban contract patterns in quicklendx-contracts

Suggested execution

• Fork the repo and create a branch
• git checkout -b feature/category-enum-sync-tests
• Implement changes
• Write contract: src/invoice.rs, src/verification.rs
• Write comprehensive tests: src/test_invoice.rs, src/test/test_invoice_categories.rs
• Add documentation: docs/contracts/invoice.md
• Include NatSpec-style comments (Rust doc comments on public items)
• Validate security assumptions

Test and commit

• Run tests
• Cover edge cases
• Include test output and security notes

Example commit message

feat: sync category list with validation allow-list

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours

[rosemary21]

@rosemary21 has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

I’d like to work on this issue because it targets data integrity and validation correctness at the contract level, which is essential for preventing invalid or unsupported categories from entering the system. If category enums drift from the validation allow-list, it can lead to inconsistent behavior, rejected transactions, or even exploitable gaps in validation logic.

This is a valuable task because it ensures:

Strict alignment between enum definitions and validation rules
Prevention of invalid or unsupported categories during uploads/updates
Early detection of drift between contract logic and allowed values
Improved auditability and developer confidence
Relevant Experience
I’ve worked on smart contract validation layers, ensuring enums and allowed values remain synchronized across modules.
Experience designing defensive validation systems, where only explicitly allowed values are accepted.
Built comprehensive test suites to detect drift between:
Enums vs validation logic
Contract state vs expected constraints
Familiar with Rust-based contract development, including modular design and doc comments for audit clarity.
I’ve implemented edge-case testing (invalid inputs, unknown enum values, boundary conditions).
Strong experience writing audit-friendly documentation and tests that clearly demonstrate invariants.
Worked with financial/verification systems, where incorrect categorization can affect downstream processing.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @rosemary21 to this issue.

[drips-wave]

Congratulations, @rosemary21! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on March 30, 2026.

🧑‍💻 @rosemary21: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊