use serde::Deserialize;
use serde::de::{self, Deserializer};
pub(crate) fn lossy_u64<'de, D>(deserializer: D) -> Result<u64, D::Error>
where
D: Deserializer<'de>,
{
#[derive(Deserialize)]
#[serde(untagged)]
enum Wire {
Num(u64),
Str(String),
}
match Wire::deserialize(deserializer)? {
Wire::Num(n) => Ok(n),
Wire::Str(s) => s.trim().parse::<u64>().map_err(de::Error::custom),
}
}
pub(crate) fn lossy_i64<'de, D>(deserializer: D) -> Result<i64, D::Error>
where
D: Deserializer<'de>,
{
#[derive(Deserialize)]
#[serde(untagged)]
enum Wire {
Num(i64),
Str(String),
}
match Wire::deserialize(deserializer)? {
Wire::Num(n) => Ok(n),
Wire::Str(s) => s.trim().parse::<i64>().map_err(de::Error::custom),
}
}
pub(crate) fn lossy_opt_u32<'de, D>(deserializer: D) -> Result<Option<u32>, D::Error>
where
D: Deserializer<'de>,
{
#[derive(Deserialize)]
#[serde(untagged)]
enum Wire {
Num(u32),
Str(String),
None,
}
match Option::<Wire>::deserialize(deserializer)? {
Some(Wire::Num(n)) => Ok(Some(n)),
Some(Wire::Str(s)) => {
let trimmed = s.trim();
if trimmed.is_empty() {
Ok(None)
} else {
trimmed.parse::<u32>().map(Some).map_err(de::Error::custom)
}
}
Some(Wire::None) | None => Ok(None),
}
}
#[cfg(test)]
mod tests {
use super::*;
use serde::Deserialize;
#[derive(Deserialize)]
struct TestItem {
#[serde(deserialize_with = "lossy_u64")]
id: u64,
#[serde(deserialize_with = "lossy_i64")]
ts: i64,
#[serde(default, deserialize_with = "lossy_opt_u32")]
count: Option<u32>,
}
#[test]
fn lossy_numeric_deserialization() {
let json = r#"{"id": "42", "ts": 123456789, "count": "10"}"#;
let item: TestItem = serde_json::from_str(json).unwrap();
assert_eq!(item.id, 42);
assert_eq!(item.ts, 123456789);
assert_eq!(item.count, Some(10));
let json2 = r#"{"id": 100, "ts": "987654321", "count": null}"#;
let item2: TestItem = serde_json::from_str(json2).unwrap();
assert_eq!(item2.id, 100);
assert_eq!(item2.ts, 987654321);
assert_eq!(item2.count, None);
}
}