Module serde_with::rust::default_on_error

Deserialize value and return Default on error

The main use case is ignoring error while deserializing. Instead of erroring, it simply deserializes the Default variant of the type. It is not possible to find the error location, i.e., which field had a deserialization error, with this method.

Examples

#[derive(Deserialize)]
struct A {
    #[serde(deserialize_with = "serde_with::rust::default_on_error::deserialize")]
    value: u32,
}

let a: A = serde_json::from_str(r#"{"value": 123}"#).unwrap();
assert_eq!(123, a.value);

// null is of invalid type
let a: A = serde_json::from_str(r#"{"value": null}"#).unwrap();
assert_eq!(0, a.value);

// String is of invalid type
let a: A = serde_json::from_str(r#"{"value": "123"}"#).unwrap();
assert_eq!(0, a.value);

// Missing entries still cause errors
assert!(serde_json::from_str::<A>(r#"{  }"#).is_err());

Deserializing missing values can be supported by adding the default field attribute:

#[derive(Deserialize)]
struct B {
    #[serde(default, deserialize_with = "serde_with::rust::default_on_error::deserialize")]
    value: u32,
}


let b: B = serde_json::from_str(r#"{  }"#).unwrap();
assert_eq!(0, b.value);

Functions

deserialize

Deserialize T and return the Default value on error