An experimental Web Application Library for Rust — a collection of building blocks for form validation, input filtering, access control, and graph-based navigation. The project is in research and development stage — please do not use it for production. Early feedback and bug reports are welcome via the issue tracker.

• Repository: https://github.com/elycruz/walrs
• Minimum supported Rust version: 1.85 (edition 2024)
• License: Elastic License 2.0

Add the root crate to get access to all sub-crates:

[dependencies]
walrs = "0.1"

Each sub-crate is re-exported as a module on the umbrella crate. A short end-to-end example using walrs::validation and walrs::filter:

use walrs::validation::{Rule, ValidateRef};
use walrs::filter::FilterOp;

// Compose validation rules
let username_rule = Rule::<String>::MinLength(3).and(Rule::MaxLength(20));
assert!(username_rule.validate_ref("alice").is_ok());
assert!(username_rule.validate_ref("ab").is_err());

// Chain input filters
let normalize = FilterOp::<String>::Chain(vec![
    FilterOp::Trim,
    FilterOp::Lowercase,
]);
assert_eq!(normalize.apply_ref("  ALICE  "), "alice");

For typed struct-based field validation (the recommended path for forms), see walrs::fieldfilter:

use walrs::fieldfilter::{Field, FieldBuilder};

All sub-crates are enabled by default. Disable features you don't need to reduce compile times:

[dependencies]
walrs = { version = "0.1", default-features = false, features = ["fieldfilter", "validation", "filter"] }

Available features: acl, digraph, filter, graph, fieldfilter, fieldfilter-derive, navigation, rbac, validation. The full aggregate feature turns on every sub-crate plus fieldfilter-derive.

fieldfilter-derive opts into the #[derive(Fieldset)] proc-macro — it implies fieldfilter and enables walrs_fieldfilter's derive feature:

[dependencies]
walrs = { version = "0.1", default-features = false, features = ["fieldfilter-derive", "validation"] }

use walrs::fieldfilter::{DeriveFieldset, Fieldset};

You can also depend on individual sub-crates directly (e.g., walrs_fieldfilter = "0.1").

walrs_fieldfilter standardises on the typed Fieldset trait (or #[derive(Fieldset)] via the fieldfilter-derive feature) — define a struct describing your fields and get statically-checked validation and filtering.

1. Install cargo-llvm-cov: cargo install cargo-llvm-cov
2. Run tests with coverage and generate HTML report: sh ./llvm-cov-all.sh or the command directly: cargo llvm-cov --html --workspace --branch
3. Open the generated report at target/llvm-cov/html/index.html in your web browser.

Cargo llvm-cov reference: https://github.com/taiki-e/cargo-llvm-cov

Note: branch and functions tracking is not supported with this method (currently).

1. Install llvm-tools: $ rustup component add llvm-tools-preview
2. Install grcov: cargo install grcov.
3. Run sh ./grcov-all.sh (builds project with instrumentation and runs tests).
4. Run the coverage "index.html" file (target/coverage/html/index.html) in the browser.

Reference: https://github.com/mozilla/grcov?tab=readme-ov-file#how-to-get-grcov

The workspace includes cargo-fuzz targets for crates that handle untrusted input.

# cargo-fuzz requires nightly Rust
rustup install nightly

# Install cargo-fuzz
cargo install cargo-fuzz

# List available targets for a crate
cd crates/validation
cargo fuzz list

# Run a specific target for 60 seconds
cargo fuzz run fuzz_email -- -max_total_time=60

# Run with a specific corpus directory
cargo fuzz run fuzz_email fuzz/corpus/fuzz_email/ -- -max_total_time=60

• Per-PR smoke runs: Every PR touching validation/filter/fieldfilter crates triggers 60-second fuzz runs per target.
• Scheduled deep runs: Weekly 30-minute runs per target on Mondays at 3 AM UTC (also manually triggerable).
• Crash artifacts are uploaded on failure for investigation.

Elastic License 2.0 (ELv2)

Free to use, modify, and distribute for personal or internal use. Commercial resale and managed-service offerings require explicit permission from the copyright holder. See NOTICE for AI-assisted development disclosure.