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Find some way for serde to fail to deserialize inputs that break invariants
Deserializing does not currently check for all invalid inputs. Also see #6 and #7.
Here is some official advice for how this could be done:
use serde::{de, Deserialize, Deserializer};
#[derive(Deserialize, Debug)]
#[serde(remote = "Self")]
struct Invariant {
/// len() >= 3
s: String,
}
impl<'de> Deserialize<'de> for Invariant {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let unchecked = Invariant::deserialize(deserializer)?;
if unchecked.s.len() < 3 {
return Err(de::Error::custom("length of `s` must be >= 3"));
}
Ok(unchecked)
}
}
fn main() {
let j = r#" {"s": "abc"} "#;
println!("{:?}", serde_json::from_str::<Invariant>(j).unwrap());
}