serde_ignored 0.0.4

Find out about keys that are ignored when deserializing data
Documentation

Serde ignored

Build Status Latest Version Rust Documentation

Find out about keys that are ignored when deserializing data. This crate provides a wrapper that works with any existing Serde Deserializer and invokes a callback on every ignored field.

You can use this to warn users about extraneous keys in a config file, for example.

Note that if you want unrecognized fields to be an error, consider using the #[serde(deny_unknown_fields)] attribute instead.

[dependencies]
serde = "1.0"
serde_ignored = "0.0.4"

#[macro_use]
extern crate serde_derive;

extern crate serde;
extern crate serde_json;
extern crate serde_ignored;

use std::collections::{BTreeSet as Set, BTreeMap as Map};

#[derive(Debug, PartialEq, Deserialize)]
struct Package {
    name: String,
    dependencies: Map<String, Dependency>,
}

#[derive(Debug, PartialEq, Deserialize)]
struct Dependency {
    version: String,
}

fn main() {
    let j = r#"{
        "name": "demo",
        "dependencies": {
            "serde": {
                "version": "0.9",
                "typo1": ""
            }
        },
        "typo2": {
            "inner": ""
        },
        "typo3": {}
    }"#;

    // Some Deserializer.
    let jd = &mut serde_json::Deserializer::from_str(j);

    // We will build a set of paths to the unused elements.
    let mut unused = Set::new();

    let p: Package = serde_ignored::deserialize(jd, |path| {
        unused.insert(path.to_string());
    }).unwrap();

    // Deserialized as normal.
    println!("{:?}", p);

    // There were three ignored keys.
    let mut expected = Set::new();
    expected.insert("dependencies.serde.typo1".to_owned());
    expected.insert("typo2".to_owned());
    expected.insert("typo3".to_owned());
    assert_eq!(unused, expected);
}

License

This crate is licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.