serde_utils/
b256_hex.rs

1use alloy_primitives::B256;
2use serde::de::Error;
3use serde::{Deserializer, Serializer};
4
5use crate::hex::PrefixedHexVisitor;
6
7pub fn serialize<S>(hash: &B256, serializer: S) -> Result<S::Ok, S::Error>
8where
9    S: Serializer,
10{
11    let mut hex_string: String = "0x".to_string();
12    hex_string.push_str(&hex::encode(&hash));
13
14    serializer.serialize_str(&hex_string)
15}
16
17pub fn deserialize<'de, D>(deserializer: D) -> Result<B256, D::Error>
18where
19    D: Deserializer<'de>,
20{
21    let decoded = deserializer.deserialize_str(PrefixedHexVisitor)?;
22
23    if decoded.len() != 32 {
24        return Err(D::Error::custom(format!(
25            "expected {} bytes for array, got {}",
26            32,
27            decoded.len()
28        )));
29    }
30
31    let mut array = [0; 32];
32    array.copy_from_slice(&decoded);
33    Ok(array.into())
34}
35
36#[cfg(test)]
37mod test {
38    use super::*;
39    use serde::{Deserialize, Serialize};
40
41    #[derive(Debug, PartialEq, Serialize, Deserialize)]
42    #[serde(transparent)]
43    struct Wrapper {
44        #[serde(with = "super")]
45        val: B256,
46    }
47
48    #[test]
49    fn encoding() {
50        assert_eq!(
51            &serde_json::to_string(&Wrapper { val: B256::ZERO }).unwrap(),
52            "\"0x0000000000000000000000000000000000000000000000000000000000000000\""
53        );
54        assert_eq!(
55            &serde_json::to_string(&Wrapper {
56                val: B256::with_last_byte(0x03)
57            })
58            .unwrap(),
59            "\"0x0000000000000000000000000000000000000000000000000000000000000003\""
60        );
61        assert_eq!(
62            &serde_json::to_string(&Wrapper {
63                val: B256::repeat_byte(0x03)
64            })
65            .unwrap(),
66            "\"0x0303030303030303030303030303030303030303030303030303030303030303\""
67        );
68    }
69
70    #[test]
71    fn decoding() {
72        assert_eq!(
73            serde_json::from_str::<Wrapper>(
74                "\"0x0000000000000000000000000000000000000000000000000000000000000000\""
75            )
76            .unwrap(),
77            Wrapper { val: B256::ZERO },
78        );
79        assert_eq!(
80            serde_json::from_str::<Wrapper>(
81                "\"0x0000000000000000000000000000000000000000000000000000000000000003\""
82            )
83            .unwrap(),
84            Wrapper {
85                val: B256::with_last_byte(0x03)
86            },
87        );
88
89        // Require 0x.
90        serde_json::from_str::<Wrapper>(
91            "\"0000000000000000000000000000000000000000000000000000000000000000\"",
92        )
93        .unwrap_err();
94        // Wrong length.
95        serde_json::from_str::<Wrapper>(
96            "\"0x00000000000000000000000000000000000000000000000000000000000000\"",
97        )
98        .unwrap_err();
99    }
100}
serde_utils/b256_hex.rs

serde_utils/
b256_hex.rs
