axum-valid

📑 Overview

axum-valid is a library that provides data validation extractors for the Axum web framework. It integrates validator, garde and validify, three popular validation crates in the Rust ecosystem, to offer convenient validation and data handling extractors for Axum applications.

🚀 Basic usage

📦 Valid<E>

• Install

cargo add validator --features derive
cargo add axum-valid
# validator is enabled by default

• Example

use axum::extract::Query;
use axum::routing::{get, post};
use axum::{Json, Router};
use axum_valid::Valid;
use serde::Deserialize;
use std::net::SocketAddr;
use tokio::net::TcpListener;
use validator::Validate;

#[derive(Debug, Validate, Deserialize)]
pub struct Paginator {
    #[validate(range(min = 1, max = 50))]
    pub page_size: usize,
    #[validate(range(min = 1))]
    pub page_no: usize,
}

pub async fn paginator_from_query(Valid(Query(paginator)): Valid<Query<Paginator>>) {
    assert!((1..=50).contains(&paginator.page_size));
    assert!((1..).contains(&paginator.page_no));
}

pub async fn paginator_from_json(paginator: Valid<Json<Paginator>>) {
    assert!((1..=50).contains(&paginator.page_size));
    assert!((1..).contains(&paginator.page_no));
    // NOTE: all extractors provided support automatic dereferencing
    println!("page_no: {}, page_size: {}", paginator.page_no, paginator.page_size);
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/query", get(paginator_from_query))
        .route("/json", post(paginator_from_json));
    let listener = TcpListener::bind(&SocketAddr::from(([0u8, 0, 0, 0], 0u16))).await?;
    axum::serve(listener, router.into_make_service()).await?;
    Ok(())
}

In case of inner extractor errors, it will first return the Rejection from the inner extractor. When validation errors occur, the outer extractor will automatically return 400 with validation errors as the HTTP message body.

📦 Garde<E>

• Install

cargo add garde --features derive
cargo add axum --features macros # for FromRef derive macro
cargo add axum-valid --features garde,basic --no-default-features
# excluding validator

• Example

use axum::extract::{FromRef, Query, State};
use axum::routing::{get, post};
use axum::{Json, Router};
use axum_valid::Garde;
use garde::Validate;
use serde::Deserialize;
use std::net::SocketAddr;
use tokio::net::TcpListener;

#[derive(Debug, Validate, Deserialize)]
pub struct Paginator {
    #[garde(range(min = 1, max = 50))]
    pub page_size: usize,
    #[garde(range(min = 1))]
    pub page_no: usize,
}

pub async fn paginator_from_query(Garde(Query(paginator)): Garde<Query<Paginator>>) {
    assert!((1..=50).contains(&paginator.page_size));
    assert!((1..).contains(&paginator.page_no));
}

pub async fn paginator_from_json(paginator: Garde<Json<Paginator>>) {
    assert!((1..=50).contains(&paginator.page_size));
    assert!((1..).contains(&paginator.page_no));
    println!("page_no: {}, page_size: {}", paginator.page_no, paginator.page_size);
}

pub async fn get_state(_state: State<MyState>) {}

#[derive(Debug, Clone, FromRef)]
pub struct MyState {
    state_field: i32,
    without_validation_arguments: (),
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/query", get(paginator_from_query))
        .route("/json", post(paginator_from_json));

    // WARNING: If you are using Garde and also have a state,
    // even if that state is unrelated to Garde,
    // you still need to implement FromRef<StateType> for ().
    // Tip: You can add an () field to your state and derive FromRef for it.
    let router = router.route("/state", get(get_state)).with_state(MyState {
        state_field: 1,
        without_validation_arguments: (),
    });
    let listener = TcpListener::bind(&SocketAddr::from(([0u8, 0, 0, 0], 0u16))).await?;
    axum::serve(listener, router.into_make_service()).await?;
    Ok(())
}

📦 Validated<E>, Modified<E>, Validified<E> and ValidifiedByRef<E>

• Install

cargo add validify
cargo add axum-valid --features validify,basic --no-default-features

• Example

Extra dependencies of this example:

cargo add axum_typed_multipart
cargo add axum-valid --features validify,basic,typed_multipart --no-default-features

use axum::extract::Query;
use axum::routing::{get, post};
use axum::{Form, Json, Router};
use axum_typed_multipart::{TryFromMultipart, TypedMultipart};
use axum_valid::{Modified, Validated, Validified, ValidifiedByRef};
use serde::Deserialize;
use std::net::SocketAddr;
use tokio::net::TcpListener;
use validify::{Payload, Validate, Validify};

#[derive(Debug, Validify, Deserialize)]
pub struct Paginator {
    #[validate(range(min = 1.0, max = 50.0))]
    pub page_size: usize,
    #[validate(range(min = 1.0))]
    pub page_no: usize,
}

pub async fn paginator_from_query(Validated(Query(paginator)): Validated<Query<Paginator>>) {
    assert!((1..=50).contains(&paginator.page_size));
    assert!((1..).contains(&paginator.page_no));
}

// Payload is now required for Validified. (Added in validify 1.3.0)
#[derive(Debug, Validify, Deserialize, Payload)]
pub struct Parameters {
    #[modify(lowercase)]
    #[validate(length(min = 1, max = 50))]
    pub v0: String,
    #[modify(trim)]
    #[validate(length(min = 1, max = 100))]
    pub v1: String,
}

pub async fn parameters_from_json(modified_parameters: Modified<Json<Parameters>>) {
    assert_eq!(
        modified_parameters.v0,
        modified_parameters.v0.to_lowercase()
    );
    assert_eq!(modified_parameters.v1, modified_parameters.v1.trim())
    // but modified_parameters may be invalid
}

// NOTE: missing required fields will be treated as validation errors.
pub async fn parameters_from_form(parameters: Validified<Form<Parameters>>) {
    assert_eq!(parameters.v0, parameters.v0.to_lowercase());
    assert_eq!(parameters.v1, parameters.v1.trim());
    assert!(parameters.validate().is_ok());
}

// NOTE: TypedMultipart doesn't using serde::Deserialize to construct data
// we should use ValidifiedByRef instead of Validified
#[derive(Debug, Validify, TryFromMultipart)]
pub struct FormData {
    #[modify(lowercase)]
    #[validate(length(min = 1, max = 50))]
    pub v0: String,
    #[modify(trim)]
    #[validate(length(min = 1, max = 100))]
    pub v1: String,
}

pub async fn parameters_from_typed_multipart(
    ValidifiedByRef(TypedMultipart(data)): ValidifiedByRef<TypedMultipart<FormData>>,
) {
    assert_eq!(data.v0, data.v0.to_lowercase());
    assert_eq!(data.v1, data.v1.trim());
    assert!(data.validate().is_ok());
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/validated", get(paginator_from_query))
        .route("/modified", post(parameters_from_json))
        .route("/validified", post(parameters_from_form))
        .route("/validified_by_ref", post(parameters_from_typed_multipart));
    let listener = TcpListener::bind(&SocketAddr::from(([0u8, 0, 0, 0], 0u16))).await?;
    axum::serve(listener, router.into_make_service()).await?;
    Ok(())
}

To see how each inner extractor can be used with validation extractors, please refer to the example in the documentation of the corresponding module.

🚀 Argument-Based Validation

📦 ValidEx<E>

• Install

cargo add validator --features derive
cargo add axum-valid
# validator is enabled by default

• Example

use axum::routing::post;
use axum::{Form, Router};
use axum_valid::ValidEx;
use serde::Deserialize;
use std::net::SocketAddr;
use std::ops::{RangeFrom, RangeInclusive};
use tokio::net::TcpListener;
use validator::{Validate, ValidationError};

// NOTE: When some fields use custom validation functions with arguments,
// `#[derive(Validate)]` will implement `ValidateArgs` instead of `Validate` for the type.
#[derive(Debug, Validate, Deserialize)]
#[validate(context = PaginatorValidArgs)] // context is required
pub struct Paginator {
    #[validate(custom(function = "validate_page_size", use_context))]
    pub page_size: usize,
    #[validate(custom(function = "validate_page_no", use_context))]
    pub page_no: usize,
}

fn validate_page_size(v: usize, args: &PaginatorValidArgs) -> Result<(), ValidationError> {
    args.page_size_range
        .contains(&v)
        .then_some(())
        .ok_or_else(|| ValidationError::new("page_size is out of range"))
}

fn validate_page_no(v: usize, args: &PaginatorValidArgs) -> Result<(), ValidationError> {
    args.page_no_range
        .contains(&v)
        .then_some(())
        .ok_or_else(|| ValidationError::new("page_no is out of range"))
}

// NOTE: Clone is required, consider using Arc to reduce deep copying costs.
#[derive(Debug, Clone)]
pub struct PaginatorValidArgs {
    page_size_range: RangeInclusive<usize>,
    page_no_range: RangeFrom<usize>,
}

pub async fn paginator_from_form_ex(ValidEx(Form(paginator)): ValidEx<Form<Paginator>>) {
    assert!((1..=50).contains(&paginator.page_size));
    assert!((1..).contains(&paginator.page_no));
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/form", post(paginator_from_form_ex))
        .with_state(PaginatorValidArgs {
            page_size_range: 1..=50,
            page_no_range: 1..,
        });
    // NOTE: The PaginatorValidArgs can also be stored in a XxxState,
    // make sure it implements FromRef<XxxState>.

    let listener = TcpListener::bind(&SocketAddr::from(([0u8, 0, 0, 0], 0u16))).await?;
    axum::serve(listener, router.into_make_service()).await?;
    Ok(())
}

📦 Garde<E>

• Install

cargo add garde
cargo add axum-valid --features garde,basic --no-default-features
# excluding validator

• Example

use axum::routing::post;
use axum::{Form, Router};
use axum_valid::Garde;
use garde::Validate;
use serde::Deserialize;
use std::net::SocketAddr;
use std::ops::{RangeFrom, RangeInclusive};
use tokio::net::TcpListener;

#[derive(Debug, Validate, Deserialize)]
#[garde(context(PaginatorValidContext))]
pub struct Paginator {
    #[garde(custom(validate_page_size))]
    pub page_size: usize,
    #[garde(custom(validate_page_no))]
    pub page_no: usize,
}

fn validate_page_size(v: &usize, args: &PaginatorValidContext) -> garde::Result {
    args.page_size_range
        .contains(&v)
        .then_some(())
        .ok_or_else(|| garde::Error::new("page_size is out of range"))
}

fn validate_page_no(v: &usize, args: &PaginatorValidContext) -> garde::Result {
    args.page_no_range
        .contains(&v)
        .then_some(())
        .ok_or_else(|| garde::Error::new("page_no is out of range"))
}

#[derive(Debug, Clone)]
pub struct PaginatorValidContext {
    page_size_range: RangeInclusive<usize>,
    page_no_range: RangeFrom<usize>,
}

pub async fn paginator_from_form_garde(Garde(Form(paginator)): Garde<Form<Paginator>>) {
    assert!((1..=50).contains(&paginator.page_size));
    assert!((1..).contains(&paginator.page_no));
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/form", post(paginator_from_form_garde))
        .with_state(PaginatorValidContext {
            page_size_range: 1..=50,
            page_no_range: 1..,
        });
    // NOTE: The PaginatorValidContext can also be stored in a XxxState,
    // make sure it implements FromRef<XxxState>.
    // Consider using Arc to reduce deep copying costs.
    let listener = TcpListener::bind(&SocketAddr::from(([0u8, 0, 0, 0], 0u16))).await?;
    axum::serve(listener, router.into_make_service()).await?;
    Ok(())
}

Current module documentation predominantly showcases Valid examples, the usage of ValidEx is analogous.

🗂️ Extractors List

⚙️ Features

🔌 Compatibility

To determine the compatible versions of dependencies that work together, please refer to the dependencies listed in the Cargo.toml file. The version numbers listed there will indicate the compatible versions.

If you encounter code compilation problems, it could be attributed to either missing trait bounds, unmet feature requirements, or incorrect dependency version selections.

📜 License

This project is licensed under the MIT License.

📚 References

• axum
• validator
• garde
• validify
• serde
• axum-extra
• axum-serde
• axum_typed_multipart
• aide