cosmwasm-std 3.0.1

Standard library for Wasm based smart contracts on Cosmos blockchains
Documentation
// This file simply re-exports some methods from serde_json
// The reason is two fold:
// 1. To easily ensure that all calling libraries use the same version (minimize code size)
// 2. To allow us to switch out to eg. serde-json-core more easily

use serde::{de::DeserializeOwned, Serialize};

use crate::{Binary, StdResult};

/// Deserializes the given JSON bytes to a data structure.
///
/// Errors if the input is not valid JSON or cannot be deserialized to the given type.
pub fn from_json<T: DeserializeOwned>(value: impl AsRef<[u8]>) -> StdResult<T> {
    Ok(serde_json::from_slice(value.as_ref())?)
}

/// Serializes the given data structure as a JSON byte vector.
pub fn to_json_vec<T>(data: &T) -> StdResult<Vec<u8>>
where
    T: Serialize + ?Sized,
{
    Ok(serde_json::to_vec(data)?)
}

/// Serializes the given data structure as a JSON string.
pub fn to_json_string<T>(data: &T) -> StdResult<String>
where
    T: Serialize + ?Sized,
{
    Ok(serde_json::to_string(data)?)
}

/// Serializes the given data structure as JSON bytes.
pub fn to_json_binary<T>(data: &T) -> StdResult<Binary>
where
    T: Serialize + ?Sized,
{
    to_json_vec(data).map(Binary::new)
}

#[cfg(test)]
mod tests {
    use super::*;
    use core::num::{
        NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroU128, NonZeroU16,
        NonZeroU32, NonZeroU64, NonZeroU8,
    };
    use proptest::{prop_assert_eq, property_test};
    use serde::Deserialize;

    use crate::msgpack::{from_msgpack, to_msgpack_vec};

    #[derive(Serialize, Deserialize, Debug, PartialEq)]
    #[serde(rename_all = "snake_case")]
    enum SomeMsg {
        Refund {},
        ReleaseAll {
            image: String,
            amount: u32,
            time: u64,
            karma: i32,
        },
        Cowsay {
            text: String,
        },
    }

    #[test]
    fn to_json_vec_works() {
        let msg = SomeMsg::Refund {};
        let serialized = to_json_vec(&msg).unwrap();
        assert_eq!(serialized, br#"{"refund":{}}"#);

        let msg = SomeMsg::ReleaseAll {
            image: "foo".to_string(),
            amount: 42,
            time: 9007199254740999, // Number.MAX_SAFE_INTEGER + 7
            karma: -17,
        };
        let serialized = String::from_utf8(to_json_vec(&msg).unwrap()).unwrap();
        assert_eq!(
            serialized,
            r#"{"release_all":{"image":"foo","amount":42,"time":9007199254740999,"karma":-17}}"#
        );
    }

    #[test]
    fn from_json_works() {
        let deserialized: SomeMsg = from_json(br#"{"refund":{}}"#).unwrap();
        assert_eq!(deserialized, SomeMsg::Refund {});

        let expected = SomeMsg::ReleaseAll {
            image: "foo".to_string(),
            amount: 42,
            time: 18446744073709551615,
            karma: -17,
        };
        // &[u8]
        let deserialized: SomeMsg = from_json(
            br#"{"release_all":{"image":"foo","amount":42,"time":18446744073709551615,"karma":-17}}"#,
        )
        .unwrap();
        assert_eq!(deserialized, expected);

        // &str
        let deserialized: SomeMsg = from_json(
            r#"{"release_all":{"image":"foo","amount":42,"time":18446744073709551615,"karma":-17}}"#,
        )
        .unwrap();
        assert_eq!(deserialized, expected);
    }

    #[test]
    fn from_json_or_binary() {
        let msg = SomeMsg::Refund {};
        let serialized: Binary = to_json_binary(&msg).unwrap();

        let parse_binary: SomeMsg = from_json(&serialized).unwrap();
        assert_eq!(parse_binary, msg);

        let parse_slice: SomeMsg = from_json(serialized.as_slice()).unwrap();
        assert_eq!(parse_slice, msg);
    }

    #[test]
    fn to_json_vec_works_for_special_chars() {
        let msg = SomeMsg::Cowsay {
            text: "foo\"bar\\\"bla".to_string(),
        };
        let serialized = String::from_utf8(to_json_vec(&msg).unwrap()).unwrap();
        assert_eq!(serialized, r#"{"cowsay":{"text":"foo\"bar\\\"bla"}}"#);
    }

    #[test]
    fn from_json_works_for_special_chars() {
        let deserialized: SomeMsg = from_json(br#"{"cowsay":{"text":"foo\"bar\\\"bla"}}"#).unwrap();
        assert_eq!(
            deserialized,
            SomeMsg::Cowsay {
                text: "foo\"bar\\\"bla".to_string(),
            }
        );
    }

    #[test]
    fn to_json_string_works() {
        let msg = SomeMsg::Refund {};
        let serialized = to_json_string(&msg).unwrap();
        assert_eq!(serialized, r#"{"refund":{}}"#);

        let msg = SomeMsg::ReleaseAll {
            image: "foo".to_string(),
            amount: 42,
            time: 9007199254740999, // Number.MAX_SAFE_INTEGER + 7
            karma: -17,
        };
        let serialized = to_json_string(&msg).unwrap();
        assert_eq!(
            serialized,
            r#"{"release_all":{"image":"foo","amount":42,"time":9007199254740999,"karma":-17}}"#
        );
    }

    macro_rules! test_integer {
        ($($ty:ty),+$(,)?) => {
            $(
                ::paste::paste! {
                    #[property_test]
                    fn [<test_ $ty:snake:lower _encoding>](input: $ty) {
                        let primitive = input.get();

                        // Verify that the serialization is the same as the primitive
                        let serialized = to_json_string(&input).unwrap();
                        let serialized_primitive = to_json_string(&primitive).unwrap();
                        prop_assert_eq!(serialized.as_str(), serialized_primitive.as_str());

                        // Verify that the serialized primitive can be deserialized
                        let deserialized: $ty = from_json(serialized_primitive).unwrap();
                        assert_eq!(deserialized, input);

                        // Verify that zero is not allowed
                        assert!(from_json::<$ty>("0").is_err());

                        // Verify that the msgpack encoding is the same as the primitive
                        let serialized = to_msgpack_vec(&input).unwrap();
                        let serialized_primitive = to_msgpack_vec(&primitive).unwrap();
                        prop_assert_eq!(serialized.as_slice(), serialized_primitive.as_slice());

                        // Verify that the serialized primitive can be deserialized
                        let deserialized: $ty = from_msgpack(&serialized_primitive).unwrap();
                        prop_assert_eq!(deserialized, input);
                    }
                }
            )+
        };
    }

    test_integer! {
        NonZeroU8,
        NonZeroU16,
        NonZeroU32,
        NonZeroU64,
        NonZeroU128,
    }

    test_integer! {
        NonZeroI8,
        NonZeroI16,
        NonZeroI32,
        NonZeroI64,
        NonZeroI128,
    }
}