use std::{str::FromStr, convert::Infallible};
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum Int32OrString {
Int(i32),
String(String),
}
impl Default for Int32OrString {
fn default() -> Self {
Int32OrString::Int(0)
}
}
impl FromStr for Int32OrString {
type Err = Infallible;
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s.parse::<i32>() {
Ok(i) => Ok(Int32OrString::Int(i)),
Err(_) => Ok(Int32OrString::String(s.to_string())),
}
}
}
impl From<i32> for Int32OrString {
fn from(f: i32) -> Self {
Int32OrString::Int(f)
}
}
impl<'de> serde::Deserialize<'de> for Int32OrString {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
struct Visitor;
impl<'de> serde::de::Visitor<'de> for Visitor {
type Value = Int32OrString;
fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(formatter, "enum Int32OrString")
}
fn visit_i32<E>(self, v: i32) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
Ok(Int32OrString::Int(v))
}
fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
if v < i64::from(i32::min_value()) || v > i64::from(i32::max_value()) {
return Err(serde::de::Error::invalid_value(
serde::de::Unexpected::Signed(v),
&"a 32-bit integer",
));
}
#[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
Ok(Int32OrString::Int(v as i32))
}
fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
#[allow(clippy::cast_sign_loss)]
{
if v > i32::max_value() as u64 {
return Err(serde::de::Error::invalid_value(
serde::de::Unexpected::Unsigned(v),
&"a 32-bit integer",
));
}
}
#[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
Ok(Int32OrString::Int(v as i32))
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
self.visit_string(v.to_string())
}
fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
Ok(Int32OrString::String(v))
}
}
deserializer.deserialize_any(Visitor)
}
}
impl serde::Serialize for Int32OrString {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
match self {
Int32OrString::Int(i) => i.serialize(serializer),
Int32OrString::String(s) => s.serialize(serializer),
}
}
}
#[cfg(test)]
mod test {
use serde_json::json;
use crate::Int32OrString;
#[test]
fn test_int_serde() {
let int_value = json!(100);
let int_or_string: Int32OrString =
serde_json::from_value(int_value.clone()).expect("failed deserialization");
assert_eq!(int_or_string, Int32OrString::Int(100));
let serialization = serde_json::to_value(&int_or_string).expect("failed serialization");
assert_eq!(int_value, serialization);
}
#[test]
fn test_invalid_float_serde() {
let int_value = json!(2.5);
let _error = serde_json::from_value::<Int32OrString>(int_value)
.expect_err("float should not be deserialized");
}
#[test]
fn test_str_serde() {
let str_value = json!("25%");
let int_or_string: Int32OrString =
serde_json::from_value(str_value.clone()).expect("failed deserialization");
assert_eq!(int_or_string, Int32OrString::String("25%".into()));
let serialization = serde_json::to_value(&int_or_string).expect("failed serialization");
assert_eq!(str_value, serialization);
}
}