alloy_sol_types/

errors.rs

// Copyright 2015-2020 Parity Technologies
// Copyright 2023-2023 Alloy Contributors

// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use alloc::{borrow::Cow, boxed::Box, collections::TryReserveError, string::String};
use alloy_primitives::{B256, LogData, hex};
use core::{cmp, fmt};

const MAX_TYPE_CHECK_FAIL_DATA_LEN: usize = 128;

/// ABI result type.
pub type Result<T, E = Error> = core::result::Result<T, E>;

/// ABI Encoding and Decoding errors.
#[derive(Clone, Debug, PartialEq)]
pub enum Error {
    /// A typecheck detected a word that does not match the data type.
    TypeCheckFail {
        /// The Solidity type we failed to produce.
        expected_type: Cow<'static, str>,
        /// Hex-encoded data, when available.
        data: String,
    },

    /// Overran deserialization buffer.
    Overrun,

    /// Allocation failed.
    Reserve(TryReserveError),

    /// Trailing bytes in deserialization buffer.
    BufferNotEmpty,

    /// Validation reserialization did not match input.
    ReserMismatch,

    /// ABI Decoding recursion limit exceeded.
    RecursionLimitExceeded(usize),

    /// ABI decoding exceeded its configured memory limit.
    MemoryLimitExceeded(usize),

    /// Invalid enum value.
    InvalidEnumValue {
        /// The name of the enum.
        name: &'static str,
        /// The invalid value.
        value: u8,
        /// The maximum valid value.
        max: u8,
    },

    /// Invalid event signature hash.
    InvalidEventSignatureHash {
        /// The event signature.
        name: &'static str,
        /// The received signature hash.
        got: B256,
        /// The expected signature hash.
        expected: B256,
    },

    /// Could not decode an event from log topics.
    InvalidLog {
        /// The name of the enum or event.
        name: &'static str,
        /// The invalid log.
        log: Box<LogData>,
    },

    /// Unknown selector.
    UnknownSelector {
        /// The type name.
        name: &'static str,
        /// The unknown selector.
        selector: alloy_primitives::FixedBytes<4>,
    },

    /// Hex error.
    FromHexError(hex::FromHexError),

    /// Other errors.
    Other(Cow<'static, str>),
}

impl core::error::Error for Error {
    fn source(&self) -> Option<&(dyn core::error::Error + 'static)> {
        match self {
            Self::Reserve(e) => Some(e),
            Self::FromHexError(e) => Some(e),
            _ => None,
        }
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::TypeCheckFail { expected_type, data } => {
                write!(f, "type check failed for {expected_type:?}")?;
                if !data.is_empty() {
                    write!(f, " with data: {data}")?;
                }
                Ok(())
            }
            Self::Overrun
            | Self::BufferNotEmpty
            | Self::ReserMismatch
            | Self::RecursionLimitExceeded(_)
            | Self::MemoryLimitExceeded(_) => {
                f.write_str("ABI decoding failed: ")?;
                match *self {
                    Self::Overrun => f.write_str("buffer overrun while deserializing"),
                    Self::BufferNotEmpty => f.write_str("buffer not empty after deserialization"),
                    Self::ReserMismatch => f.write_str("reserialization did not match original"),
                    Self::RecursionLimitExceeded(limit) => {
                        write!(f, "recursion limit of {limit} exceeded during decoding")
                    }
                    Self::MemoryLimitExceeded(limit) => {
                        write!(f, "memory limit of {limit} bytes exceeded during decoding")
                    }
                    _ => unreachable!(),
                }
            }
            Self::Reserve(e) => e.fmt(f),
            Self::InvalidEnumValue { name, value, max } => {
                write!(f, "`{value}` is not a valid {name} enum value (max: `{max}`)")
            }
            Self::InvalidEventSignatureHash { name, got, expected } => {
                write!(
                    f,
                    "invalid signature hash for event {name:?}: got {got}, expected {expected}"
                )
            }
            Self::InvalidLog { name, log } => {
                write!(f, "could not decode {name} from log: {log:?}")
            }
            Self::UnknownSelector { name, selector } => {
                write!(f, "unknown selector `{selector}` for {name}")
            }
            Self::FromHexError(e) => e.fmt(f),
            Self::Other(e) => f.write_str(e),
        }
    }
}

impl Error {
    /// Instantiates a new error with a static str.
    #[cold]
    pub fn custom(s: impl Into<Cow<'static, str>>) -> Self {
        Self::Other(s.into())
    }

    /// Instantiates a new [`Error::TypeCheckFail`] with the provided data.
    #[cold]
    pub fn type_check_fail_sig(mut data: &[u8], signature: &'static str) -> Self {
        if data.len() > 4 {
            data = &data[..4];
        }
        let expected_type = signature.split('(').next().unwrap();
        Self::type_check_fail(data, expected_type)
    }

    /// Instantiates a new [`Error::TypeCheckFail`] with the provided token.
    #[cold]
    pub fn type_check_fail_token<T: crate::SolType>(_token: &T::Token<'_>) -> Self {
        Self::type_check_fail(&[], T::SOL_NAME)
    }

    /// Instantiates a new [`Error::TypeCheckFail`] with the provided data.
    #[cold]
    pub fn type_check_fail(data: &[u8], expected_type: impl Into<Cow<'static, str>>) -> Self {
        let data = &data[..cmp::min(data.len(), MAX_TYPE_CHECK_FAIL_DATA_LEN)];
        Self::TypeCheckFail { expected_type: expected_type.into(), data: hex::encode(data) }
    }

    /// Instantiates a new [`Error::UnknownSelector`] with the provided data.
    #[cold]
    pub fn unknown_selector(name: &'static str, selector: [u8; 4]) -> Self {
        Self::UnknownSelector { name, selector: selector.into() }
    }

    #[doc(hidden)] // Not public API.
    #[cold]
    pub const fn invalid_event_signature_hash(
        name: &'static str,
        got: B256,
        expected: B256,
    ) -> Self {
        Self::InvalidEventSignatureHash { name, got, expected }
    }
}

impl From<hex::FromHexError> for Error {
    #[inline]
    fn from(value: hex::FromHexError) -> Self {
        Self::FromHexError(value)
    }
}

impl From<TryReserveError> for Error {
    #[inline]
    fn from(value: TryReserveError) -> Self {
        Self::Reserve(value)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use alloc::string::ToString;

    #[test]
    fn type_check_fail_data_is_bounded() {
        let error = Error::type_check_fail(&[0; MAX_TYPE_CHECK_FAIL_DATA_LEN + 1], "test");
        let Error::TypeCheckFail { data, .. } = error else { unreachable!() };
        assert_eq!(data.len(), MAX_TYPE_CHECK_FAIL_DATA_LEN * 2);
    }

    #[test]
    fn type_check_fail_token_omits_token_data() {
        let token = crate::abi::token::WordToken(crate::Word::ZERO);
        let error = Error::type_check_fail_token::<crate::sol_data::Bool>(&token);
        let Error::TypeCheckFail { data, .. } = error else { unreachable!() };
        assert!(data.is_empty());
    }

    #[test]
    fn empty_type_check_fail_data_is_not_displayed() {
        assert_eq!(
            Error::type_check_fail(&[], "test").to_string(),
            "type check failed for \"test\""
        );
    }
}