Serde ignored

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.

toml [dependencies] serde = "0.9" serde_ignored = "0.0.1"

```rust

[macro_use]

extern crate serde_derive;

extern crate serde; extern crate serdejson; extern crate serdeignored;

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

[derive(Debug, PartialEq, Deserialize)]

struct Package { name: String, dependencies: Map, }

[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

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

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.