axum-serde

📑 Overview

axum-serde is a library that provides multiple serde-based extractors / responses for the Axum web framework. It also offers a macro to easily customize extractors and responses without writing much boilerplate code.

If you were using crates like axum-yaml, axum-msgpack etc. in axum 0.6 and wish to upgrade to axum 0.7, axum-serde can be used as a replacement to simplify the migration, without having to modify existing code too much.

🚀 Basic usage

• Install

cargo add axum-serde --features yaml,sonic
# Enable features as you need

• Example

use axum::routing::post;
use axum::Router;
use axum_serde::{Sonic, Yaml};
use serde::{Deserialize, Serialize};
use std::net::{Ipv4Addr, SocketAddr};
use tokio::net::TcpListener;

#[derive(Deserialize, Serialize)]
pub struct Data {
    pub a: i32,
    pub b: String,
}

pub async fn yaml_to_json(Yaml(data): Yaml<Data>) -> Sonic<Data> {
    Sonic(data)
}

pub async fn json_to_yaml(Sonic(data): Sonic<Data>) -> Yaml<Data> {
    Yaml(data)
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/y2j", post(yaml_to_json))
        .route("/j2y", post(json_to_yaml));
    let listener = TcpListener::bind(&SocketAddr::from((Ipv4Addr::UNSPECIFIED, 8080))).await?;
    axum::serve(listener, router.into_make_service()).await?;
    Ok(())
}

• Test

curl -X POST http://localhost:8080/y2j -H "Content-Type: application/yaml" -d $'a: 42\nb: Hello'
curl -X POST http://localhost:8080/j2y -H "Content-Type: application/json" -d '{"a": 42, "b": "Hello, world!"}'

🗂️ Extractors / responses

Extractor	Feature	Backend
Yaml<T>	yaml	serde_yaml v0.9.33
MsgPack<T> / MsgPackRaw<T>	msgpack	rmp-serde v1.3.0
Toml<T>	toml	toml v0.8.14
Xml<T>	xml	quick-xml v0.37.0
Sonic<T>	sonic	sonic-rs v0.3.7
Cbor<T>	cbor	ciborium v0.2.2

🎁 Custom extractor / response

Use the extractor macro to create custom extractors with minimal boilerplate:

• Example

use axum_serde::{
    extractor,
    macros::{DeserializeOwned, Serialize},
};

extractor!(
    MyFormat,                   // The name of the data format.
    MyFmt,                      // The actual type name of the HTTP extractor/response.
    "application/myfmt",        // The Content-Type that this extractor supports.
    from_slice,                 // A function identifier for deserializing data from the HTTP request body.
    String,                     // The type of error that can occur when deserializing from the request body.
    to_vec,                     // A function identifier for serializing the HTTP response body to bytes.
    myfmt                       // The test module name.
);

fn from_slice<T: DeserializeOwned>(_bytes: &[u8]) -> Result<T, String> {
    todo!()
}

fn to_vec<T: Serialize>(_value: &T) -> Result<Vec<u8>, String> {
    todo!()
}

• Test

More dev-dependencies are required to run the tests:

# Add dev-dependencies for tests
cargo add axum-test --dev
cargo add serde --features derive --dev
cargo add tokio --features macros --dev

# Run the generated tests
cargo test myfmt

📜 License

This project is licensed under the MIT License.

📚 References

• axum
• serde