express_rs

A minimal and blazing-fast web framework for Rust, inspired by Express.js

🚀 Overview

express_rs aims to provide a clean, expressive, and flexible web framework modeled after the ergonomics of Express.js, but with the performance and safety guarantees of Rust.

The goal is to keep things simple, fast, and ergonomic — no macros, no ceremony — just modular, async-first routing, middlewares, and handler composition.

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✅ Features (Implemented)

• Express-style routing with .get(), .post(), etc.
• Middleware system (app.use(...)) with layered composition
• Minimal App type (no macro or derive required)
• Request + Response types with mutable APIs
• Route parameter extraction (/user/:id)
• Route handler abstraction (Handler) with Next
• Logging with method, path and elapsed time
• Built-in response helpers (e.g., .send(), .json(), .status())
• File serving with streaming optimization + LRU cache
• MIME type detection (via [mime_guess] and [infer])
• Route matching via fast radix tree (matchthem)
• Global string interner for path and param deduplication
• Type-safe per-request parameter access via extension API
• MethodKind enum + method bitflag support

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🛠️ Goals & Roadmap

Core Architecture

• Internal App struct with lazy router initialization
• Router type with per-method route trees
• Middleware pipeline with early return support
• Symbol-based interned parameters

Developer Experience

• Static type-safe API for request extensions (.locals, etc.)
• Global AppState<T> support like Actix
• Built-in logging/tracing macros with levels
• Built-in .env support for config (optional)
• Pluggable middleware (logger, body-parser, etc.)

Advanced Routing

• Path prefix mounting (app.use('/api', apiApp))
• Route grouping (router.route('/users').get(...).post(...))
• Optional trailing slash handling
• Regex or wildcard segments (* / .*)

Performance

• Benchmarks against Axum/Actix/Warp
• Zero-copy response body writing
• Avoid all heap allocations in hot path
• Smallvec for handler/index lists

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🧪 Example

use express_rs::App;

fn main() {
    let mut app = App::default();

    app.get("/", |req, res, _| {
        res.send("Hello from Rust!");
    });

    app.listen(3000, || {
        println!("🚀 Listening on http://localhost:3000");
    });
}