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 Pager {
    #[validate(range(min = 1, max = 50))]
    pub page_size: usize,
    #[validate(range(min = 1))]
    pub page_no: usize,
}

pub async fn pager_from_query(Valid(Query(pager)): Valid<Query<Pager>>) {
    assert!((1..=50).contains(&pager.page_size));
    assert!((1..).contains(&pager.page_no));
}

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

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/query", get(pager_from_query))
        .route("/json", post(pager_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-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 Pager {
    #[garde(range(min = 1, max = 50))]
    pub page_size: usize,
    #[garde(range(min = 1))]
    pub page_no: usize,
}

pub async fn pager_from_query(Garde(Query(pager)): Garde<Query<Pager>>) {
    assert!((1..=50).contains(&pager.page_size));
    assert!((1..).contains(&pager.page_no));
}

pub async fn pager_from_json(pager: Garde<Json<Pager>>) {
    assert!((1..=50).contains(&pager.page_size));
    assert!((1..).contains(&pager.page_no));
    println!("page_no: {}, page_size: {}", pager.page_no, pager.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(pager_from_query))
        .route("/json", post(pager_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 Pager {
    #[validate(range(min = 1.0, max = 50.0))]
    pub page_size: usize,
    #[validate(range(min = 1.0))]
    pub page_no: usize,
}

pub async fn pager_from_query(Validated(Query(pager)): Validated<Query<Pager>>) {
    assert!((1..=50).contains(&pager.page_size));
    assert!((1..).contains(&pager.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(pager_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 = PagerValidArgs)] // context is required
pub struct Pager {
    #[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: &PagerValidArgs) -> 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: &PagerValidArgs) -> 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 PagerValidArgs {
    page_size_range: RangeInclusive<usize>,
    page_no_range: RangeFrom<usize>,
}

pub async fn pager_from_form_ex(ValidEx(Form(pager)): ValidEx<Form<Pager>>) {
    assert!((1..=50).contains(&pager.page_size));
    assert!((1..).contains(&pager.page_no));
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/form", post(pager_from_form_ex))
        .with_state(PagerValidArgs {
            page_size_range: 1..=50,
            page_no_range: 1..,
        });
    // NOTE: The PagerValidArgs 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(PagerValidContext))]
pub struct Pager {
    #[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: &PagerValidContext) -> 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: &PagerValidContext) -> 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 PagerValidContext {
    page_size_range: RangeInclusive<usize>,
    page_no_range: RangeFrom<usize>,
}

pub async fn pager_from_form_garde(Garde(Form(pager)): Garde<Form<Pager>>) {
    assert!((1..=50).contains(&pager.page_size));
    assert!((1..).contains(&pager.page_no));
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let router = Router::new()
        .route("/form", post(pager_from_form_garde))
        .with_state(PagerValidContext {
            page_size_range: 1..=50,
            page_no_range: 1..,
        });
    // NOTE: The PagerValidContext 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

Extractor	Backend / Feature	Data's trait bound	Functionality	Benefits	Drawbacks
Valid<E>	validator	validator::Validate	Validation
ValidEx<E>	validator	validator::ValidateArgs	Validation with arguments
Garde<E>	garde	garde::Validate	Validation with or without arguments		Require empty tuple as the argument if use state
Validated<E>	validify	validify::Validate	Validation
Modified<E>	validify	validify::Modify	Modification / Conversion to response
Validified<E>	validify	validify::Validify, validify::ValidifyPayload and serde::DeserializeOwned	Construction, modification, validation	Treat missing fields as validation errors	Only works with extractors using serde
ValidifiedByRef<E>	validify	validify::Validate and validify::Modify	Modification, validation

⚙️ Features

Feature	Description	Module	Default	Example	Tests
default	Enables validator and support for Query, Json and Form	[validator], [query], [json], [form]	✅	✅	✅
validator	Enables validator (Valid, ValidEx)	[validator]	✅	✅	✅
garde	Enables garde (Garde)	[garde]	❌	✅	✅
validify	Enables validify (Validated, Modified, Validified, ValidifedByRef)	[validify]	❌	✅	✅
basic	Enables support for Query, Json and Form	[query], [json], [form]	✅	✅	✅
json	Enables support for Json	[json]	✅	✅	✅
query	Enables support for Query	[query]	✅	✅	✅
form	Enables support for Form	[form]	✅	✅	✅
typed_header	Enables support for TypedHeader from axum-extra	[typed_header]	❌	✅	✅
typed_multipart	Enables support for TypedMultipart and BaseMultipart from axum_typed_multipart	[typed_multipart]	❌	✅	✅
msgpack	Enables support for MsgPack and MsgPackRaw from axum-serde	[msgpack]	❌	✅	✅
yaml	Enables support for Yaml from axum-serde	[yaml]	❌	✅	✅
xml	Enables support for Xml from axum-serde	[xml]	❌	✅	✅
toml	Enables support for Toml from axum-serde	[toml]	❌	✅	✅
sonic	Enables support for Sonic from axum-serde	[sonic]	❌	✅	✅
cbor	Enables support for Cbor from axum-serde	[cbor]	❌	✅	✅
extra	Enables support for Cached, WithRejection from axum-extra	[extra]	❌	✅	✅
extra_typed_path	Enables support for T: TypedPath from axum-extra	[extra::typed_path]	❌	✅	✅
extra_query	Enables support for Query from axum-extra	[extra::query]	❌	✅	✅
extra_form	Enables support for Form from axum-extra	[extra::form]	❌	✅	✅
extra_protobuf	Enables support for Protobuf from axum-extra	[extra::protobuf]	❌	✅	✅
all_extra_types	Enables support for all extractors above from axum-extra	N/A	❌	✅	✅
all_types	Enables support for all extractors above	N/A	❌	✅	✅
422	Use 422 Unprocessable Entity instead of 400 Bad Request as the status code when validation fails	[VALIDATION_ERROR_STATUS]	❌	✅	✅
into_json	Validation errors will be serialized into JSON format and returned as the HTTP body	N/A	❌	✅	✅
full_validator	Enables validator, all_types, 422 and into_json	N/A	❌	✅	✅
full_garde	Enables garde, all_types, 422 and into_json. Consider using default-features = false to exclude default validator support	N/A	❌	✅	✅
full_garde	Enables validify, all_types, 422 and into_json. Consider using default-features = false to exclude default validator support	N/A	❌	✅	✅
full	Enables all features above	N/A	❌	✅	✅
aide	Enables support for aide	N/A	❌	❌	❌

🔌 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