Struct serde_with::DefaultOnError[−][src]

#[serde_as]
#[derive(Deserialize, Debug)]
struct A {
    #[serde_as(deserialize_as = "DefaultOnError")]
    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);

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

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

#[serde_as]
#[derive(Deserialize)]
struct B {
    #[serde_as(deserialize_as = "DefaultOnError")]
    #[serde(default)]
    value: u32,
}

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

#[serde_as]
#[derive(Serialize, Deserialize)]
struct C {
    #[serde_as(as = "Vec<DefaultOnError<DisplayFromStr>>")]
    value: Vec<u32>,
};

let c: C = serde_json::from_value(json!({
    "value": ["1", "2", "a3", "", {}, "6"]
})).unwrap();
assert_eq!(vec![1, 2, 0, 0, 0, 6], c.value);