serdev_derive 0.2.0

• Just a wrapper of Serde and 100% compatible
• Declarative validation in deserialization by #[serde(validate = "...")]

Example

[dependencies]
serdev     = "0.2"
serde_json = "1.0"

use serdev::{Serialize, Deserialize};

#[derive(Serialize, Deserialize, Debug)]
#[serde(validate = "Self::validate")]
struct Point {
    x: i32,
    y: i32,
}

impl Point {
    fn validate(&self) -> Result<(), impl std::fmt::Display> {
        if self.x * self.y > 100 {
            return Err("x * y must not exceed 100")
        }
        Ok(())
    }
}

fn main() {
    let point = serde_json::from_str::<Point>(r#"
        { "x" : 1, "y" : 2 }
    "#).unwrap();

    // Prints point = Point { x: 1, y: 2 }
    println!("point = {point:?}");

    let error = serde_json::from_str::<Point>(r#"
        { "x" : 10, "y" : 20 }
    "#).unwrap_err();

    // Prints error = x * y must not exceed 100
    println!("error = {error}");
}

Of course, you can use it in combination with some validation tools like validator! ( full example )

Attribute

• #[serde(validate = "function")]

  Automatically validate by the function in deserialization. The function must be callable as fn(&self) -> Result<(), impl Display>.
  Errors are converted to a String internally and passed to serde::de::Error::custom.

• #[serde(validate(by = "function", error = "Type"))]

  Using given Type for validation error without internal conversion. The function must explicitly return Result<(), Type>.
  This may be preferred when you need better performance even in error cases.
  For no-std use, this is the only way supported.

Both "function" and "Type" accept path like "crate::util::validate".

Additionally, #[serdev(crate = "path::to::serdev")] is supported for reexport from another crate.

License

Licensed under MIT LICENSE ( LICENSE or https://opensource.org/licenses/MIT ).