Task 31: Malformed Error Taxonomy TOML Files Can Be Merged Without Validation

[grantfox-oss]

The core error taxonomy relies on TOML files (e.g., contract.toml, auth.toml) curated by developers and contributors. Because these are plain text files, they are highly susceptible to human error. A contributor might accidentally type a string where an integer is expected, forget a required description field, or accidentally duplicate an error code. If a corrupted TOML file is merged into the grat core repository, it will poison the entire decoding pipeline, causing runtime crashes or mislabeled diagnostics across all IDE and Web platforms relying on the data. Currently, there is no automated defense mechanism preventing malformed data from being introduced.

Issues/what to fix

A rigorous, build time TaxonomyLinter must be engineered in Rust. This linter will act as a strict schema validator. It must utilize the serde framework to strictly deserialize the TOML files against a strongly typed Rust struct (TaxonomySchema). The linter must implement custom validation hooks to enforce strict business logic rules: Every error code must be a unique integer; no two errors can share the same numeric value within a category. Descriptions must exceed a minimum character length to prevent useless entries like "Error occurred". If any rule is violated, the linter must immediately panic with a highly detailed, line specific error message. This linter must be integrated into the #[test] suite so that the Continuous Integration (CI) pipeline instantly fails any Pull Request containing invalid TOML modifications.

Files to create / modify

Create: crates/core/src/taxonomy/linter.rs

Expected result

The Grat repository will be permanently safeguarded against human error and data corruption. Contributors will receive immediate, automated feedback if they format an error entry incorrectly, ensuring the core taxonomy remains mathematically pristine and 100% reliable for downstream consumers.

Contributor telegram group

https://t.me/+sII7WPhll2liMGNk

[Lspnjr1]

Hello maintainers,

I’d like to work on this issue and would appreciate being assigned if it’s available. I’ve reviewed the details and am confident I can implement the changes, test them thoroughly, and submit a pull request once complete. I expect to finish the issue and open a PR within 2–3 days.

Thank you.

[tali-creator]

I would like to work on this issue. I have experience with Rust, validation logic, and maintaining code quality through automated testing. My approach will be to build a strict TaxonomyLinter that uses serde to deserialize the TOML taxonomy files into a strongly typed TaxonomySchema, followed by custom validation to enforce all business rules.

The implementation will verify unique integer error codes within each category, enforce minimum description lengths, and produce clear, line-specific error messages whenever validation fails. I will also integrate the linter into the existing #[test] suite so that malformed taxonomy changes immediately fail CI, preventing corrupted data from reaching downstream consumers.

I will ensure the solution is well tested, maintainable, and aligns with the project's existing architecture and coding standards.

[CodeMayor]

I'd like to work on this issue because it strengthens the reliability of the project's core taxonomy by preventing malformed TOML definitions from reaching downstream consumers. I'll implement a robust Rust-based taxonomy linter with strict schema validation, custom business-rule checks, and CI-integrated tests to ensure invalid taxonomy changes are caught early.

[grantfox-oss]

🦊 GrantFox — @tali-creator 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 #344)
2. Your PR will be reviewed by the Toolbox-Lab maintainers

Good luck! Track your progress on GrantFox.