Serde Valid

This is JSON Schema based validation tool using with serde.

Usage

You derive Validate trait, and write validations.

use serde_valid::Validate;

#[derive(Validate)]
struct SampleStruct {
    #[validate(minimum = 0)]
    #[validate(maximum = 10)]
    val: i32,
}

#[derive(Validate)]
enum SampleEnum {
    Named {
        #[validate]
        a: SampleStruct,
    },
    UnNamed(
        #[validate(minimum = 0)]
        #[validate(maximum = 10)]
        i32,
    ),
}

let s = SampleEnum::Named {
    a: SampleStruct { val: 5 },
};

assert!(s.validate().is_ok());

Validations

Serde Valid support standard validation based JSON Schema.

Complete Constructor (Deserialization)

Serde Valid support complete constructor method using by serde_valid::json::FromJson trait.

use serde::Deserialize;
use serde_valid::Validate;
use serde_valid::json::{json, FromJson};

#[derive(Debug, Deserialize, Validate)]
struct SampleStruct {
    #[validate(maximum = 100)]
    val: i32,
}

// Deserialization and Validation!! 🚀
let err = SampleStruct::from_json_value(json!({ "val": 123 })).unwrap_err();

assert_eq!(
    serde_json::to_value(err.as_validation_errors().unwrap()).unwrap(),
    json!({ "val": [ "the number must be `<= 100`." ] })
);

You can force validation by only deserialization through serde_valid, and removing serde_json from Cargo.toml of your project.

Serialization

For serialization, provides serde_valid::json::ToJson trait.

use serde::Serialize;
use serde_valid::Validate;
use serde_valid::json::{json, ToJson};

#[derive(Debug, Serialize, Validate)]
struct SampleStruct {
    #[validate(maximum = 100)]
    val: i32,
}

assert_eq!(
    SampleStruct{ val: 12i32 }.to_json_string().unwrap(),
    json!({ "val": 12i32 }).to_json_string().unwrap()
);

Custom Message

For user custom message, Serde Valid provides message_fn or message.

use serde_json::json;
use serde_valid::Validate;

fn min_error_message(_params: &serde_valid::MinItemsErrorParams) -> String {
    "this is min custom message_fn.".to_string()
}

#[derive(Validate)]
struct SampleStruct {
    #[validate(min_items = 4, message_fn(min_error_message))]
    #[validate(max_items = 2, message = "this is max custom message.")]
    val: Vec<i32>,
}

let s = SampleStruct { val: vec![1, 2, 3] };

assert_eq!(
    serde_json::to_string(&s.validate().unwrap_err()).unwrap(),
    serde_json::to_string(&json!({
        "val": [
            "this is min custom message_fn.",
            "this is max custom message."
        ]
    }))
    .unwrap()
);

Custom method

You can use your custom validation using by #[validate(custom)].

use serde_valid::Validate;

fn user_validation(_val: &i32) -> Result<(), serde_valid::validation::Error> {
    Ok(())
}

#[derive(Validate)]
struct SampleStruct {
    #[validate(custom(user_validation))]
    val: i32,
}

let s = SampleStruct { val: 1 };

assert!(s.validate().is_ok());

Rules

If you want to check multi fields validation, you can use #[rule].

use serde_json::json;
use serde_valid::Validate;

fn sample_rule(_val1: &i32, _val2: &str) -> Result<(), serde_valid::validation::Error> {
    Err(serde_valid::validation::Error::Custom(
        "Rule error is added to the first arg of the rule_method.".to_owned(),
    ))
}

#[derive(Validate)]
#[rule(sample_rule(val2, val1))]
struct SampleStruct {
    val1: String,
    val2: i32,
}

let s = SampleStruct {
    val1: "val1".to_owned(),
    val2: 1,
};

assert_eq!(
    serde_json::to_string(&s.validate().unwrap_err()).unwrap(),
    serde_json::to_string(&json!({
        "val2": [
            "Rule error is added to the first arg of the rule_method."
        ]
    }))
    .unwrap()
);

If you want to use rule to unnamed fields struct, just like this,

use serde_json::json;
use serde_valid::Validate;

fn sample_rule(_val1: &i32, _val2: &str) -> Result<(), serde_valid::validation::Error> {
    Ok(())
}

#[derive(Validate)]
#[rule(sample_rule(0, 1))]
struct SampleStruct(i32, String);

let s = SampleStruct(0, "1".to_owned());

assert!(s.validate().is_ok());

Validate Traits

By implementing the validation trait, Your original type can uses Serde Valid validations.

use serde_valid::Validate;

struct MyType(String);

impl serde_valid::ValidateMaxLength for MyType {
    fn validate_max_length(&self, max_length: usize) -> Result<(), serde_valid::MaxLengthErrorParams> {
        self.0.validate_max_length(max_length)
    }
}

impl serde_valid::ValidateMinLength for MyType {
    fn validate_min_length(&self, min_length: usize) -> Result<(), serde_valid::MinLengthErrorParams> {
        self.0.validate_min_length(min_length)
    }
}

#[derive(Validate)]
struct SampleStruct {
    #[validate(min_length = 5)]
    #[validate(max_length = 5)]
    val: MyType,
}

let s = SampleStruct {
    val: MyType(String::from("😍👺🙋🏽👨‍🎤👨‍👩‍👧‍👦")),
};

assert!(s.validate().is_ok());