alloy_sol_types/abi/

decoder.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 crate::{
    Error, Result, Word,
    abi::{Token, token::TokenSeq},
    utils,
};
use alloc::vec::Vec;
use alloy_primitives::hex;
use core::{cell::Cell, fmt, mem, slice::SliceIndex};

/// The decoder recursion limit.
///
/// This is the default value used by [`AbiDecoderConfig`].
#[deprecated(note = "use `AbiDecoderConfig` to configure the recursion limit")]
pub const RECURSION_LIMIT: usize = 16;

const DEFAULT_MEMORY_LIMIT: usize = 1 << 30;

/// Configuration for ABI decoding.
#[allow(missing_copy_implementations, missing_debug_implementations)]
pub struct AbiDecoderConfig {
    recursion_limit: usize,
    memory_limit: usize,
    validate: bool,
    strict: bool,
    validate_allow_trailing_bytes: bool,
}

impl Default for AbiDecoderConfig {
    #[inline]
    fn default() -> Self {
        Self::new()
    }
}

impl Clone for AbiDecoderConfig {
    #[inline]
    fn clone(&self) -> Self {
        *self
    }
}

impl Copy for AbiDecoderConfig {}

impl fmt::Debug for AbiDecoderConfig {
    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("AbiDecoderConfig")
            .field("recursion_limit", &self.recursion_limit)
            .field("memory_limit", &self.memory_limit)
            .field("validate", &self.validate)
            .field("strict", &self.strict)
            .field("validate_allow_trailing_bytes", &self.validate_allow_trailing_bytes)
            .finish()
    }
}

impl AbiDecoderConfig {
    /// Creates a decoder configuration with the default limits.
    #[inline]
    pub const fn new() -> Self {
        Self {
            recursion_limit: 16,
            memory_limit: DEFAULT_MEMORY_LIMIT,
            validate: false,
            strict: false,
            validate_allow_trailing_bytes: false,
        }
    }

    /// Returns the maximum recursion depth.
    #[inline]
    pub const fn get_recursion_limit(&self) -> usize {
        self.recursion_limit
    }

    /// Returns the maximum amount of memory that decoding may allocate.
    #[inline]
    pub const fn get_memory_limit(&self) -> usize {
        self.memory_limit
    }

    /// Returns whether decoded tokens are validated before detokenization.
    #[inline]
    pub const fn get_validate(&self) -> bool {
        self.validate || self.get_strict()
    }

    /// Returns whether strict ABI encoding is required.
    ///
    /// Trailing bytes are permitted when
    /// [`get_validate_allow_trailing_bytes`](Self::get_validate_allow_trailing_bytes)
    /// is enabled.
    #[inline]
    pub const fn get_strict(&self) -> bool {
        self.strict
    }

    /// Returns whether strict validation permits trailing bytes.
    #[inline]
    pub const fn get_validate_allow_trailing_bytes(&self) -> bool {
        self.validate_allow_trailing_bytes
    }

    /// Sets the maximum recursion depth.
    #[inline]
    pub const fn recursion_limit(mut self, limit: usize) -> Self {
        self.recursion_limit = limit;
        self
    }

    /// Sets the maximum amount of memory that decoding may allocate.
    #[inline]
    pub const fn memory_limit(mut self, limit: usize) -> Self {
        self.memory_limit = limit;
        self
    }

    /// Enables or disables decoded token validation before detokenization.
    ///
    /// When enabled, high-level ABI decode helpers call the target Solidity
    /// type's token validator before converting the token into the returned
    /// Rust value. This rejects dirty bool bytes, invalid strings, and other
    /// token values that can be decoded from ABI words but do not satisfy the
    /// target type's validity rules.
    #[inline]
    pub const fn validate(mut self, validate: bool) -> Self {
        self.validate = validate;
        self
    }

    /// Requires strictly ABI-encoded input.
    ///
    /// Strict mode implies `validate`.
    /// It also rejects gaps or overlaps between dynamic data areas while decoding.
    /// Trailing bytes are rejected unless
    /// [`validate_allow_trailing_bytes`](Self::validate_allow_trailing_bytes) is enabled.
    #[inline]
    pub const fn strict(mut self, strict: bool) -> Self {
        self.strict = strict;
        self
    }

    /// Allows trailing bytes when strict ABI decoding is enabled.
    ///
    /// This does not enable [`strict`](Self::strict) or [`validate`](Self::validate).
    /// In strict mode, it skips the final check that the encoding consumes the entire
    /// input. All other strict checks, including canonical offsets, complete zero padding,
    /// and token validation, remain enabled. This matches Solidity's acceptance of trailing
    /// bytes only; it does not relax the other checks that Solidity omits. Without strict
    /// mode, trailing bytes are already permitted.
    ///
    /// This option permits trailing bytes even when `strict(true)` is also set,
    /// regardless of setter order. Disabling it leaves the other configuration flags
    /// unchanged.
    ///
    /// ```
    /// use alloy_sol_types::{SolType, abi::AbiDecoderConfig, sol_data::Uint};
    ///
    /// let mut data = Uint::<8>::abi_encode(&42);
    /// data.extend_from_slice(&[0xaa, 0xbb]);
    /// let config = AbiDecoderConfig::new().strict(true).validate_allow_trailing_bytes(true);
    /// assert_eq!(Uint::<8>::abi_decode_with_config(&data, config)?, 42);
    /// # Ok::<(), alloy_sol_types::Error>(())
    /// ```
    #[inline]
    pub const fn validate_allow_trailing_bytes(mut self, allow: bool) -> Self {
        self.validate_allow_trailing_bytes = allow;
        self
    }

    /// Sets the maximum recursion depth in place.
    #[inline]
    pub const fn set_recursion_limit(&mut self, limit: usize) {
        self.recursion_limit = limit;
    }

    /// Sets the maximum amount of memory that decoding may allocate in place.
    #[inline]
    pub const fn set_memory_limit(&mut self, limit: usize) {
        self.memory_limit = limit;
    }

    /// Enables or disables decoded token validation before detokenization.
    #[inline]
    pub const fn set_validate(&mut self, validate: bool) {
        self.validate = validate;
    }

    /// Requires or allows non-strict ABI encoding in place.
    #[inline]
    pub const fn set_strict(&mut self, strict: bool) {
        self.strict = strict;
    }

    /// Sets [`validate_allow_trailing_bytes`](Self::validate_allow_trailing_bytes) in place.
    #[inline]
    pub const fn set_validate_allow_trailing_bytes(&mut self, allow: bool) {
        self.validate_allow_trailing_bytes = allow;
    }
}

enum DecoderState<'state> {
    Root {
        memory_used: Cell<usize>,
        strict_next_offset: Cell<usize>,
    },
    Child {
        memory_used: &'state Cell<usize>,
        strict_next_offset: Cell<usize>,
        strict_parent: Option<StrictParent<'state>>,
    },
}

impl<'state> DecoderState<'state> {
    #[inline]
    const fn memory_used(&self) -> &Cell<usize> {
        match self {
            Self::Root { memory_used, .. } => memory_used,
            Self::Child { memory_used, .. } => memory_used,
        }
    }

    #[inline]
    const fn strict_next_offset(&self) -> &Cell<usize> {
        match self {
            Self::Root { strict_next_offset, .. } | Self::Child { strict_next_offset, .. } => {
                strict_next_offset
            }
        }
    }

    #[inline]
    const fn strict_parent(&self) -> Option<&StrictParent<'state>> {
        match self {
            Self::Root { .. } => None,
            Self::Child { strict_parent, .. } => strict_parent.as_ref(),
        }
    }
}

struct StrictParent<'state> {
    next_offset: &'state Cell<usize>,
    start: usize,
}

/// The [`Decoder`] wraps a byte slice with necessary info to progressively
/// deserialize the bytes into a sequence of tokens.
///
/// # Usage Note
///
/// While the Decoder contains the necessary info, the actual deserialization
/// is done in the [`crate::SolType`] trait.
pub struct Decoder<'de, 'state> {
    // The underlying buffer.
    buf: &'de [u8],
    // The current offset in the buffer.
    offset: usize,
    /// The current recursion depth.
    depth: usize,
    /// The decoder configuration.
    config: AbiDecoderConfig,
    /// Shared decoder state.
    state: DecoderState<'state>,
}

impl fmt::Debug for Decoder<'_, '_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut body = self.buf.chunks(32).map(hex::encode_prefixed).collect::<Vec<_>>();
        if let Some(word) = body.get_mut(self.offset / 32) {
            word.push_str(" <-- Next Word");
        }

        f.debug_struct("Decoder")
            .field("buf", &body)
            .field("offset", &self.offset)
            .field("depth", &self.depth)
            .field("config", &self.config)
            .finish()
    }
}

impl fmt::Display for Decoder<'_, '_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        writeln!(f, "Abi Decode Buffer")?;

        for (i, chunk) in self.buf.chunks(32).enumerate() {
            let idx = i * 32;
            writeln!(
                f,
                "0x{idx:04x}: {}{}",
                hex::encode_prefixed(chunk),
                if idx == self.offset { " <-- Next Word" } else { "" }
            )?;
        }
        Ok(())
    }
}

impl<'de> Decoder<'de, 'static> {
    /// Instantiates a new decoder from a byte slice.
    #[inline]
    pub const fn new(buf: &'de [u8]) -> Self {
        Self::with_config(buf, AbiDecoderConfig::new())
    }

    #[inline]
    const fn with_config(buf: &'de [u8], config: AbiDecoderConfig) -> Self {
        Self {
            buf,
            offset: 0,
            depth: 0,
            config,
            state: DecoderState::Root {
                memory_used: Cell::new(0),
                strict_next_offset: Cell::new(0),
            },
        }
    }
}

impl<'de, 'state> Decoder<'de, 'state> {
    #[inline]
    const fn new_child<'child>(parent: &'child Self, buf: &'de [u8]) -> Decoder<'de, 'child> {
        Decoder {
            buf,
            offset: 0,
            depth: parent.depth + 1,
            config: parent.config,
            state: DecoderState::Child {
                memory_used: parent.memory_used(),
                strict_next_offset: Cell::new(0),
                strict_parent: if parent.config.get_strict() {
                    Some(StrictParent {
                        next_offset: parent.state.strict_next_offset(),
                        start: parent.buf.len() - buf.len(),
                    })
                } else {
                    None
                },
            },
        }
    }

    #[inline]
    const fn memory_used(&self) -> &Cell<usize> {
        self.state.memory_used()
    }

    /// Sets the size of the current zone's head in words for strict decoding.
    #[doc(hidden)]
    #[inline]
    pub fn set_strict_head_words(&self, words: usize) -> Result<()> {
        if self.config.get_strict() {
            let bytes = words.checked_mul(Word::len_bytes()).ok_or(Error::Overrun)?;
            let offset = self.offset.checked_add(bytes).ok_or(Error::Overrun)?;
            let next = self.state.strict_next_offset();
            next.set(next.get().max(offset));
        }
        Ok(())
    }

    #[inline]
    pub(crate) const fn is_strict(&self) -> bool {
        self.config.get_strict()
    }

    /// Returns the current offset in the buffer.
    #[inline]
    pub const fn offset(&self) -> usize {
        self.offset
    }

    /// Returns the number of bytes in the remaining buffer.
    #[inline]
    pub const fn remaining(&self) -> Option<usize> {
        self.buf.len().checked_sub(self.offset)
    }

    /// Returns the number of words in the remaining buffer.
    #[inline]
    pub const fn remaining_words(&self) -> usize {
        if let Some(remaining) = self.remaining() { remaining / Word::len_bytes() } else { 0 }
    }

    /// Returns a reference to the remaining bytes in the buffer.
    #[inline]
    pub fn remaining_buf(&self) -> Option<&'de [u8]> {
        self.buf.get(self.offset..)
    }

    /// Returns whether the remaining buffer is empty.
    #[inline]
    pub const fn is_empty(&self) -> bool {
        match self.remaining() {
            Some(0) | None => true,
            Some(_) => false,
        }
    }

    /// Create a child decoder, starting at `offset` bytes from the current
    /// decoder's offset.
    ///
    /// See [`child`](Self::child).
    #[inline]
    pub fn raw_child<'child>(&'child self) -> Result<Decoder<'de, 'child>> {
        self.child(self.offset)
    }

    /// Create a child decoder, starting at `offset` bytes from the current
    /// decoder's offset.
    /// The child decoder shares the buffer.
    #[inline]
    pub fn child<'child>(&'child self, offset: usize) -> Result<Decoder<'de, 'child>, Error> {
        let recursion_limit = self.config.get_recursion_limit();
        if self.depth >= recursion_limit {
            return Err(Error::RecursionLimitExceeded(recursion_limit));
        }
        match self.buf.get(offset..) {
            Some(buf) => Ok(Self::new_child(self, buf)),
            None => Err(Error::Overrun),
        }
    }

    /// Registers an allocation against the configured memory limit.
    #[doc(hidden)]
    #[inline]
    pub fn reserve(&mut self, bytes: usize) -> Result<()> {
        let memory_limit = self.config.get_memory_limit();
        let used = self
            .memory_used()
            .get()
            .checked_add(bytes)
            .ok_or(Error::MemoryLimitExceeded(memory_limit))?;
        if used > memory_limit {
            return Err(Error::MemoryLimitExceeded(memory_limit));
        }
        self.memory_used().set(used);
        Ok(())
    }

    #[doc(hidden)]
    #[inline]
    pub fn reserve_elements<T>(&mut self, len: usize) -> Result<()> {
        let bytes = len
            .checked_mul(mem::size_of::<T>())
            .ok_or(Error::MemoryLimitExceeded(self.config.get_memory_limit()))?;
        self.reserve(bytes)
    }

    /// Advance the offset by `len` bytes.
    #[inline]
    const fn increase_offset(&mut self, len: usize) {
        self.offset += len;
    }

    /// Peek into the buffer.
    #[inline]
    pub fn peek<I: SliceIndex<[u8]>>(&self, index: I) -> Result<&'de I::Output, Error> {
        self.buf.get(index).ok_or(Error::Overrun)
    }

    /// Peek a slice of size `len` from the buffer at a specific offset, without
    /// advancing the offset.
    #[inline]
    pub fn peek_len_at(&self, offset: usize, len: usize) -> Result<&'de [u8], Error> {
        let end = offset.checked_add(len).ok_or(Error::Overrun)?;
        self.peek(offset..end)
    }

    /// Peek a slice of size `len` from the buffer without advancing the offset.
    #[inline]
    pub fn peek_len(&self, len: usize) -> Result<&'de [u8], Error> {
        self.peek_len_at(self.offset, len)
    }

    /// Peek a word from the buffer at a specific offset, without advancing the
    /// offset.
    #[inline]
    pub fn peek_word_at(&self, offset: usize) -> Result<&'de Word, Error> {
        self.peek_len_at(offset, Word::len_bytes()).map(|w| <&Word>::try_from(w).unwrap())
    }

    /// Peek the next word from the buffer without advancing the offset.
    #[inline]
    pub fn peek_word(&self) -> Result<&'de Word, Error> {
        self.peek_word_at(self.offset)
    }

    /// Peek a `usize` from the buffer at a specific offset, without advancing
    /// the offset.
    #[inline]
    pub fn peek_offset_at(&self, offset: usize) -> Result<usize> {
        self.peek_word_at(offset).and_then(utils::as_offset)
    }

    /// Peek a `usize` from the buffer, without advancing the offset.
    #[inline]
    pub fn peek_offset(&self) -> Result<usize> {
        self.peek_word().and_then(utils::as_offset)
    }

    /// Take a word from the buffer, advancing the offset.
    #[inline]
    pub fn take_word(&mut self) -> Result<&'de Word, Error> {
        let contents = self.peek_word()?;
        self.increase_offset(Word::len_bytes());
        Ok(contents)
    }

    /// Return a child decoder by consuming a word, interpreting it as a
    /// pointer, and following it.
    #[inline]
    pub fn take_indirection<'child>(&'child mut self) -> Result<Decoder<'de, 'child>, Error> {
        let offset = self.take_offset()?;
        if self.is_strict() && offset != self.state.strict_next_offset().get() {
            return Err(Error::ReserMismatch);
        }
        self.child(offset)
    }

    /// Takes a `usize` offset from the buffer by consuming a word.
    #[inline]
    pub fn take_offset(&mut self) -> Result<usize> {
        self.take_word().and_then(utils::as_offset)
    }

    /// Takes a slice of bytes of the given length.
    #[inline]
    pub fn take_slice(&mut self, len: usize) -> Result<&'de [u8]> {
        self.peek_len(len).inspect(|_| self.increase_offset(len))
    }

    /// Takes a padded slice and validates its padding in strict mode.
    #[doc(hidden)]
    #[inline]
    pub fn take_padded_slice(&mut self, len: usize) -> Result<&'de [u8]> {
        let bytes = self.take_slice(len)?;
        if self.is_strict() {
            let padding = (Word::len_bytes() - len % Word::len_bytes()) % Word::len_bytes();
            if self.take_slice(padding)?.iter().any(|&byte| byte != 0) {
                return Err(Error::ReserMismatch);
            }
        }
        Ok(bytes)
    }

    /// Takes the offset from the child decoder and sets it as the current
    /// offset.
    #[inline]
    pub const fn take_offset_from(&mut self, child: &Decoder<'de, '_>) {
        self.set_offset(self.offset_from_child(child));
    }

    /// Returns the parent-relative offset from a child decoder.
    #[inline]
    pub const fn offset_from_child(&self, child: &Decoder<'de, '_>) -> usize {
        child.offset + (self.buf.len() - child.buf.len())
    }

    /// Sets the current offset in the buffer.
    #[inline]
    pub const fn set_offset(&mut self, offset: usize) {
        self.offset = offset;
    }

    /// Decodes a single token from the underlying buffer.
    #[inline]
    pub fn decode<T: Token<'de>>(&mut self) -> Result<T> {
        T::decode_from(self)
    }

    /// Decodes a sequence of tokens from the underlying buffer.
    #[inline]
    pub fn decode_sequence<T: Token<'de> + TokenSeq<'de>>(&mut self) -> Result<T> {
        T::decode_sequence(self)
    }
}

impl Drop for Decoder<'_, '_> {
    fn drop(&mut self) {
        if let Some(parent) = self.state.strict_parent() {
            let offset =
                parent.start.saturating_add(self.offset.max(self.state.strict_next_offset().get()));
            parent.next_offset.set(parent.next_offset.get().max(offset));
        }
    }
}

/// ABI-decodes a token by wrapping it in a single-element tuple.
///
/// You are probably looking for
/// [`SolValue::abi_decode`](crate::SolValue::abi_decode) if you are not
/// intending to use raw tokens.
///
/// See the [`abi`](super) module for more information.
#[inline(always)]
pub fn decode<'de, T: Token<'de>>(data: &'de [u8]) -> Result<T> {
    decode_with_config(data, AbiDecoderConfig::default())
}

/// ABI-decodes a token with the given configuration.
#[inline(always)]
pub fn decode_with_config<'de, T: Token<'de>>(
    data: &'de [u8],
    config: AbiDecoderConfig,
) -> Result<T> {
    decode_sequence_with_config::<(T,)>(data, config).map(|(t,)| t)
}

/// ABI-decodes top-level function args.
///
/// Decodes as function parameters if [`T` is a tuple](TokenSeq::IS_TUPLE).
/// Otherwise, decodes it as a single-element tuple.
///
/// You are probably looking for
/// [`SolValue::abi_decode_params`](crate::SolValue::abi_decode_params) if
/// you are not intending to use raw tokens.
///
/// See the [`abi`](super) module for more information.
#[inline(always)]
pub fn decode_params<'de, T: TokenSeq<'de>>(data: &'de [u8]) -> Result<T> {
    decode_params_with_config(data, AbiDecoderConfig::default())
}

/// ABI-decodes top-level function args with the given configuration.
#[inline(always)]
pub fn decode_params_with_config<'de, T: TokenSeq<'de>>(
    data: &'de [u8],
    config: AbiDecoderConfig,
) -> Result<T> {
    if T::IS_TUPLE {
        decode_sequence_with_config(data, config)
    } else {
        decode_with_config(data, config)
    }
}

/// Decodes ABI compliant vector of bytes into vector of tokens described by
/// types param.
///
/// You are probably looking for
/// [`SolValue::abi_decode_sequence`](crate::SolValue::abi_decode_sequence) if
/// you are not intending to use raw tokens.
///
/// See the [`abi`](super) module for more information.
#[inline]
pub fn decode_sequence<'de, T: TokenSeq<'de>>(data: &'de [u8]) -> Result<T> {
    decode_sequence_with_config(data, AbiDecoderConfig::default())
}

/// Decodes an ABI-compliant sequence into tokens with the given configuration.
#[inline]
pub fn decode_sequence_with_config<'de, T: TokenSeq<'de>>(
    data: &'de [u8],
    config: AbiDecoderConfig,
) -> Result<T> {
    let mut decoder = Decoder::with_config(data, config);
    let result = decoder.decode_sequence::<T>()?;
    if config.get_strict()
        && !config.get_validate_allow_trailing_bytes()
        && decoder.state.strict_next_offset().get() != data.len()
    {
        return Err(Error::ReserMismatch);
    }
    Ok(result)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{SolCall, SolType, SolValue, sol, sol_data, utils::pad_usize};
    use alloc::string::ToString;
    use alloy_primitives::{Address, B256, U256, address, bytes, hex};

    #[test]
    fn dynamic_array_of_dynamic_arrays() {
        type MyTy = sol_data::Array<sol_data::Array<sol_data::Address>>;
        let encoded = hex!(
            "
    		0000000000000000000000000000000000000000000000000000000000000020
    		0000000000000000000000000000000000000000000000000000000000000002
    		0000000000000000000000000000000000000000000000000000000000000040
    		0000000000000000000000000000000000000000000000000000000000000080
    		0000000000000000000000000000000000000000000000000000000000000001
    		0000000000000000000000001111111111111111111111111111111111111111
    		0000000000000000000000000000000000000000000000000000000000000001
    		0000000000000000000000002222222222222222222222222222222222222222
    	"
        );

        let ty = vec![vec![Address::repeat_byte(0x11)], vec![Address::repeat_byte(0x22)]];
        assert_eq!(MyTy::abi_encode_params(&ty), encoded);

        let decoded = MyTy::abi_decode_params(&encoded).unwrap();
        assert_eq!(decoded, ty);
        assert_eq!(decoded.abi_encode_params(), encoded);
        assert_eq!(decoded.abi_encoded_size(), encoded.len());
    }

    #[test]
    fn decode_static_tuple_of_addresses_and_uints() {
        type MyTy = (sol_data::Address, sol_data::Address, sol_data::Uint<256>);

        let encoded = hex!(
            "
    		0000000000000000000000001111111111111111111111111111111111111111
    		0000000000000000000000002222222222222222222222222222222222222222
    		1111111111111111111111111111111111111111111111111111111111111111
    	"
        );
        let address1 = Address::from([0x11u8; 20]);
        let address2 = Address::from([0x22u8; 20]);
        let uint = U256::from_be_bytes::<32>([0x11u8; 32]);
        let expected = (address1, address2, uint);
        let decoded = MyTy::abi_decode_sequence(&encoded).unwrap();
        assert_eq!(decoded, expected);
        assert_eq!(decoded.abi_encode_params(), encoded);
        assert_eq!(decoded.abi_encoded_size(), encoded.len());
    }

    #[test]
    fn decode_dynamic_tuple() {
        type MyTy = (sol_data::String, sol_data::String);
        let encoded = hex!(
            "
    		0000000000000000000000000000000000000000000000000000000000000020
    		0000000000000000000000000000000000000000000000000000000000000040
    		0000000000000000000000000000000000000000000000000000000000000080
    		0000000000000000000000000000000000000000000000000000000000000009
    		6761766f66796f726b0000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000009
    		6761766f66796f726b0000000000000000000000000000000000000000000000
    	"
        );
        let string1 = "gavofyork".to_string();
        let string2 = "gavofyork".to_string();
        let expected = (string1, string2);

        // this test vector contains a top-level indirect
        let decoded = MyTy::abi_decode(&encoded).unwrap();
        assert_eq!(decoded, expected);
        assert_eq!(decoded.abi_encode(), encoded);
        assert_eq!(decoded.abi_encoded_size(), encoded.len());
    }

    #[test]
    fn decode_nested_tuple() {
        type MyTy = (
            sol_data::String,
            sol_data::Bool,
            sol_data::String,
            (sol_data::String, sol_data::String, (sol_data::String, sol_data::String)),
        );

        let encoded = hex!(
            "
    		0000000000000000000000000000000000000000000000000000000000000020
    		0000000000000000000000000000000000000000000000000000000000000080
    		0000000000000000000000000000000000000000000000000000000000000001
    		00000000000000000000000000000000000000000000000000000000000000c0
    		0000000000000000000000000000000000000000000000000000000000000100
    		0000000000000000000000000000000000000000000000000000000000000004
    		7465737400000000000000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000006
    		6379626f72670000000000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000060
    		00000000000000000000000000000000000000000000000000000000000000a0
    		00000000000000000000000000000000000000000000000000000000000000e0
    		0000000000000000000000000000000000000000000000000000000000000005
    		6e69676874000000000000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000003
    		6461790000000000000000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000040
    		0000000000000000000000000000000000000000000000000000000000000080
    		0000000000000000000000000000000000000000000000000000000000000004
    		7765656500000000000000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000008
    		66756e7465737473000000000000000000000000000000000000000000000000
    	"
        );
        let string1 = "test".into();
        let string2 = "cyborg".into();
        let string3 = "night".into();
        let string4 = "day".into();
        let string5 = "weee".into();
        let string6 = "funtests".into();
        let bool = true;
        let deep_tuple = (string5, string6);
        let inner_tuple = (string3, string4, deep_tuple);
        let expected = (string1, bool, string2, inner_tuple);

        let decoded = MyTy::abi_decode(&encoded).unwrap();
        assert_eq!(decoded, expected);
        assert_eq!(decoded.abi_encode(), encoded);
        assert_eq!(decoded.abi_encoded_size(), encoded.len());
    }

    #[test]
    fn decode_complex_tuple_of_dynamic_and_static_types() {
        type MyTy = (sol_data::Uint<256>, sol_data::String, sol_data::Address, sol_data::Address);

        let encoded = hex!(
            "
    		0000000000000000000000000000000000000000000000000000000000000020
    		1111111111111111111111111111111111111111111111111111111111111111
    		0000000000000000000000000000000000000000000000000000000000000080
    		0000000000000000000000001111111111111111111111111111111111111111
    		0000000000000000000000002222222222222222222222222222222222222222
    		0000000000000000000000000000000000000000000000000000000000000009
    		6761766f66796f726b0000000000000000000000000000000000000000000000
    	"
        );
        let uint = U256::from_be_bytes::<32>([0x11u8; 32]);
        let string = "gavofyork".to_string();
        let address1 = Address::from([0x11u8; 20]);
        let address2 = Address::from([0x22u8; 20]);
        let expected = (uint, string, address1, address2);

        let decoded = MyTy::abi_decode(&encoded).unwrap();
        assert_eq!(decoded, expected);
        assert_eq!(decoded.abi_encode(), encoded);
        assert_eq!(decoded.abi_encoded_size(), encoded.len());
    }

    #[test]
    fn decode_params_containing_dynamic_tuple() {
        type MyTy = (
            sol_data::Address,
            (sol_data::Bool, sol_data::String, sol_data::String),
            sol_data::Address,
            sol_data::Address,
            sol_data::Bool,
        );

        let encoded = hex!(
            "
    		0000000000000000000000002222222222222222222222222222222222222222
    		00000000000000000000000000000000000000000000000000000000000000a0
    		0000000000000000000000003333333333333333333333333333333333333333
    		0000000000000000000000004444444444444444444444444444444444444444
    		0000000000000000000000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000001
    		0000000000000000000000000000000000000000000000000000000000000060
    		00000000000000000000000000000000000000000000000000000000000000a0
    		0000000000000000000000000000000000000000000000000000000000000009
    		7370616365736869700000000000000000000000000000000000000000000000
    		0000000000000000000000000000000000000000000000000000000000000006
    		6379626f72670000000000000000000000000000000000000000000000000000
    	"
        );
        let address1 = Address::from([0x22u8; 20]);
        let bool1 = true;
        let string1 = "spaceship".to_string();
        let string2 = "cyborg".to_string();
        let tuple = (bool1, string1, string2);
        let address2 = Address::from([0x33u8; 20]);
        let address3 = Address::from([0x44u8; 20]);
        let bool2 = false;
        let expected = (address1, tuple, address2, address3, bool2);

        let decoded = MyTy::abi_decode_params(&encoded).unwrap();
        assert_eq!(decoded, expected);
        assert_eq!(decoded.abi_encode_params(), encoded);
        assert_eq!(decoded.abi_encoded_size(), encoded.len() + 32);
    }

    #[test]
    fn decode_params_containing_static_tuple() {
        type MyTy = (
            sol_data::Address,
            (sol_data::Address, sol_data::Bool, sol_data::Bool),
            sol_data::Address,
            sol_data::Address,
        );

        let encoded = hex!(
            "
    		0000000000000000000000001111111111111111111111111111111111111111
    		0000000000000000000000002222222222222222222222222222222222222222
    		0000000000000000000000000000000000000000000000000000000000000001
    		0000000000000000000000000000000000000000000000000000000000000000
    		0000000000000000000000003333333333333333333333333333333333333333
    		0000000000000000000000004444444444444444444444444444444444444444
    	"
        );
        let address1 = Address::from([0x11u8; 20]);
        let address2 = Address::from([0x22u8; 20]);
        let bool1 = true;
        let bool2 = false;
        let tuple = (address2, bool1, bool2);
        let address3 = Address::from([0x33u8; 20]);
        let address4 = Address::from([0x44u8; 20]);

        let expected = (address1, tuple, address3, address4);

        let decoded = MyTy::abi_decode_params(&encoded).unwrap();
        assert_eq!(decoded, expected);
    }

    #[test]
    fn decode_data_with_size_that_is_not_a_multiple_of_32() {
        type MyTy = (
            sol_data::Uint<256>,
            sol_data::String,
            sol_data::String,
            sol_data::Uint<256>,
            sol_data::Uint<256>,
        );

        let data = (
            pad_usize(0).into(),
            "12203967b532a0c14c980b5aeffb17048bdfaef2c293a9509f08eb3c6b0f5f8f0942e7b9cc76ca51cca26ce546920448e308fda6870b5e2ae12a2409d942de428113P720p30fps16x9".to_string(),
            "93c717e7c0a6517a".to_string(),
            pad_usize(1).into(),
            pad_usize(5538829).into()
        );

        let encoded = hex!(
            "
            0000000000000000000000000000000000000000000000000000000000000000
            00000000000000000000000000000000000000000000000000000000000000a0
            0000000000000000000000000000000000000000000000000000000000000152
            0000000000000000000000000000000000000000000000000000000000000001
            000000000000000000000000000000000000000000000000000000000054840d
            0000000000000000000000000000000000000000000000000000000000000092
            3132323033393637623533326130633134633938306235616566666231373034
            3862646661656632633239336139353039663038656233633662306635663866
            3039343265376239636337366361353163636132366365353436393230343438
            6533303866646136383730623565326165313261323430396439343264653432
            3831313350373230703330667073313678390000000000000000000000000000
            0000000000000000000000000000000000103933633731376537633061363531
            3761
        "
        );

        assert_eq!(MyTy::abi_decode_sequence(&encoded).unwrap(), data);
    }

    #[test]
    fn decode_after_fixed_bytes_with_less_than_32_bytes() {
        type MyTy = (
            sol_data::Address,
            sol_data::FixedBytes<32>,
            sol_data::FixedBytes<4>,
            sol_data::String,
        );

        let encoded = hex!(
            "
    		0000000000000000000000008497afefdc5ac170a664a231f6efb25526ef813f
    		0101010101010101010101010101010101010101010101010101010101010101
    		0202020202020202020202020202020202020202020202020202020202020202
    		0000000000000000000000000000000000000000000000000000000000000080
    		000000000000000000000000000000000000000000000000000000000000000a
    		3078303030303030314600000000000000000000000000000000000000000000
    	    "
        );

        assert_eq!(
            MyTy::abi_decode_params(&encoded).unwrap(),
            (
                address!("0x8497afefdc5ac170a664a231f6efb25526ef813f"),
                B256::repeat_byte(0x01),
                [0x02; 4].into(),
                "0x0000001F".into(),
            )
        );
    }

    #[test]
    fn decode_broken_utf8() {
        let encoded = hex!(
            "
    		0000000000000000000000000000000000000000000000000000000000000020
    		0000000000000000000000000000000000000000000000000000000000000004
    		e4b88de500000000000000000000000000000000000000000000000000000000
            "
        );

        assert_eq!(sol_data::String::abi_decode(&encoded).unwrap(), "不�".to_string());
    }

    #[test]
    #[cfg_attr(miri, ignore = "OOM https://github.com/rust-lang/miri/issues/3637")]
    fn decode_corrupted_dynamic_array() {
        type MyTy = sol_data::Array<sol_data::Uint<32>>;
        // line 1 at 0x00 =   0: tail offset of array
        // line 2 at 0x20 =  32: length of array
        // line 3 at 0x40 =  64: first word
        // line 4 at 0x60 =  96: second word
        let encoded = hex!(
            "
    	0000000000000000000000000000000000000000000000000000000000000020
    	00000000000000000000000000000000000000000000000000000000ffffffff
    	0000000000000000000000000000000000000000000000000000000000000001
    	0000000000000000000000000000000000000000000000000000000000000002
        "
        );
        assert!(MyTy::abi_decode_sequence(&encoded).is_err());
    }

    #[test]
    fn decode_dynamic_array_preallocation() {
        type MyTy = sol_data::Array<sol_data::Uint<32>>;
        let mut encoded = Vec::with_capacity(64);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(usize::MAX).as_slice());

        let err = MyTy::abi_decode_sequence(&encoded).unwrap_err();
        assert_eq!(err, Error::Overrun);
    }

    #[test]
    fn decode_dynamic_array_of_zero_sized_type() {
        type MyTy = sol_data::Array<()>;
        let mut encoded = Vec::with_capacity(64);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(2).as_slice());

        assert_eq!(MyTy::abi_decode_sequence(&encoded).unwrap(), vec![(), ()]);
    }

    #[test]
    fn decode_huge_dynamic_array_of_zero_sized_type_exceeds_memory_limit() {
        type MyTy = sol_data::Array<()>;
        let mut encoded = Vec::with_capacity(64);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(u32::MAX as usize).as_slice());

        assert_eq!(
            decode_sequence::<<MyTy as SolType>::Token<'_>>(&encoded),
            Err(Error::MemoryLimitExceeded(DEFAULT_MEMORY_LIMIT)),
        );
    }

    #[test]
    fn decode_nested_dynamic_array_of_zero_sized_type() {
        type MyTy = sol_data::Array<sol_data::Array<()>>;
        let mut encoded = Vec::with_capacity(128);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(1).as_slice());
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(2).as_slice());

        assert_eq!(MyTy::abi_decode_sequence(&encoded).unwrap(), vec![vec![(), ()]]);
    }

    #[test]
    fn decode_dynamic_array_of_multiword_static_type() {
        type MyTy = sol_data::Array<sol_data::FixedArray<sol_data::Uint<32>, 2>>;
        let mut encoded = Vec::with_capacity(96);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(1).as_slice());
        // The fixed-array element requires two words, but only one is provided.
        encoded.extend_from_slice(pad_usize(1).as_slice());

        let err = MyTy::abi_decode_sequence(&encoded).unwrap_err();
        assert_eq!(err, Error::Overrun);
    }

    #[test]
    fn decode_dynamic_array_required_words_overflow() {
        type MyTy = sol_data::Array<sol_data::FixedArray<sol_data::Uint<32>, 2>>;
        let mut encoded = Vec::with_capacity(64);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(usize::MAX).as_slice());

        let err = MyTy::abi_decode_sequence(&encoded).unwrap_err();
        assert_eq!(err, Error::Overrun);
    }

    #[test]
    fn decode_dynamic_array_of_dynamic_type() {
        type MyTy = sol_data::Array<sol_data::Array<sol_data::FixedArray<sol_data::Uint<32>, 3>>>;
        let mut encoded = Vec::with_capacity(128);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(1).as_slice());
        // The dynamic element requires one offset word regardless of its inner static width.
        encoded.extend_from_slice(pad_usize(32).as_slice());
        // The nested array is empty, so no fixed-array data follows.
        encoded.extend_from_slice(pad_usize(0).as_slice());

        let decoded = MyTy::abi_decode_sequence(&encoded).unwrap();
        assert_eq!(decoded.len(), 1);
        assert!(decoded[0].is_empty());
    }

    #[test]
    fn decode_verify_addresses() {
        let input = hex!(
            "
    	0000000000000000000000000000000000000000000000000000000000012345
    	0000000000000000000000000000000000000000000000000000000000054321
    	"
        );

        assert_eq!(
            sol_data::Address::abi_decode(&input).unwrap(),
            address!("0000000000000000000000000000000000012345")
        );
        assert!(<(sol_data::Address, sol_data::Address)>::abi_decode(&input).is_ok());
    }

    #[test]
    fn decode_verify_bytes() {
        type MyTy2 = (sol_data::Address, sol_data::Address);

        let input = hex!(
            "
    	0000000000000000000000001234500000000000000000000000000000012345
    	0000000000000000000000005432100000000000000000000000000000054321
    	"
        );
        assert!(MyTy2::abi_decode_params(&input).is_ok());
    }

    #[test]
    fn signed_int_dirty_high_bytes() {
        type MyTy = sol_data::Int<8>;

        let dirty_negative =
            hex!("f0ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");

        assert_eq!(MyTy::abi_decode(&dirty_negative).unwrap(), -1);

        let dirty_positive =
            hex!("700000000000000000000000000000000000000000000000000000000000007f");

        assert_eq!(MyTy::abi_decode(&dirty_positive).unwrap(), 127);
    }

    // https://github.com/alloy-rs/core/issues/433
    #[test]
    fn fixed_before_dynamic() {
        sol! {
            #[derive(Debug, PartialEq, Eq)]
            struct Ty {
                bytes32[3] arr;
                bytes dyn;
            }
        }

        let ty = Ty {
            arr: [[0x11u8; 32].into(), [0x22u8; 32].into(), [0x33u8; 32].into()],
            r#dyn: bytes![0x44u8; 4],
        };
        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000020"
            "1111111111111111111111111111111111111111111111111111111111111111"
            "2222222222222222222222222222222222222222222222222222222222222222"
            "3333333333333333333333333333333333333333333333333333333333333333"
            "0000000000000000000000000000000000000000000000000000000000000080"
            "0000000000000000000000000000000000000000000000000000000000000004"
            "4444444400000000000000000000000000000000000000000000000000000000"
        );
        assert_eq!(hex::encode(ty.abi_encode()), hex::encode(encoded));
        assert_eq!(ty.abi_encoded_size(), encoded.len());

        assert_eq!(<Ty as SolType>::abi_decode(&encoded).unwrap(), ty);
    }

    #[test]
    fn dynarray_before_dynamic() {
        sol! {
            #[derive(Debug, PartialEq, Eq)]
            struct Ty {
                bytes[3] arr;
                bytes dyn;
            }
        }

        let ty = Ty {
            arr: [bytes![0x11u8; 32], bytes![0x22u8; 32], bytes![0x33u8; 32]],
            r#dyn: bytes![0x44u8; 4],
        };
        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000020" // struct offset
            "0000000000000000000000000000000000000000000000000000000000000040" // arr offset
            "0000000000000000000000000000000000000000000000000000000000000160" // dyn offset
            "0000000000000000000000000000000000000000000000000000000000000060" // arr[0] offset
            "00000000000000000000000000000000000000000000000000000000000000a0" // arr[1] offset
            "00000000000000000000000000000000000000000000000000000000000000e0" // arr[2] offset
            "0000000000000000000000000000000000000000000000000000000000000020" // arr[0]
            "1111111111111111111111111111111111111111111111111111111111111111"
            "0000000000000000000000000000000000000000000000000000000000000020" // arr[1]
            "2222222222222222222222222222222222222222222222222222222222222222"
            "0000000000000000000000000000000000000000000000000000000000000020" // arr[2]
            "3333333333333333333333333333333333333333333333333333333333333333"
            "0000000000000000000000000000000000000000000000000000000000000004" // dyn
            "4444444400000000000000000000000000000000000000000000000000000000"
        );
        assert_eq!(hex::encode(ty.abi_encode()), hex::encode(encoded));
        assert_eq!(ty.abi_encoded_size(), encoded.len());

        assert_eq!(<Ty as SolType>::abi_decode(&encoded).unwrap(), ty);
    }

    #[test]
    fn offset_overflow() {
        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000020"
            "000000000000000000000000000000000000000000000000ffffffffffffffff"
            "0000000000000000000000000000000000000000000000000000000000000000"
        );
        let err = <sol_data::String as SolType>::abi_decode(&encoded).unwrap_err();
        assert_eq!(err, Error::Overrun);
    }

    #[test]
    fn config_defaults_and_setters() {
        let mut config = AbiDecoderConfig::new();
        assert_eq!(config.get_recursion_limit(), 16);
        assert_eq!(config.get_memory_limit(), DEFAULT_MEMORY_LIMIT);
        assert!(!config.get_validate());
        assert!(!config.get_strict());
        assert!(!config.get_validate_allow_trailing_bytes());

        config.set_recursion_limit(300);
        config.set_memory_limit(42);
        config.set_validate(true);
        config.set_strict(true);
        assert_eq!(config.get_recursion_limit(), 300);
        assert_eq!(config.get_memory_limit(), 42);
        assert!(config.get_validate());
        assert!(config.get_strict());

        let config = AbiDecoderConfig::new().recursion_limit(400).memory_limit(24).strict(true);
        assert_eq!(config.get_recursion_limit(), 400);
        assert_eq!(config.get_memory_limit(), 24);
        assert!(config.get_validate());
        assert!(config.get_strict());
    }

    #[test]
    fn validate_allow_trailing_bytes_config() {
        let mut config = AbiDecoderConfig::new().validate_allow_trailing_bytes(true);
        assert!(!config.get_validate());
        assert!(!config.get_strict());
        assert!(config.get_validate_allow_trailing_bytes());

        config.set_validate_allow_trailing_bytes(false);
        assert!(!config.get_validate());
        assert!(!config.get_strict());
        assert!(!config.get_validate_allow_trailing_bytes());

        config.set_strict(true);
        config.set_validate_allow_trailing_bytes(true);
        config.set_validate_allow_trailing_bytes(false);
        assert!(config.get_strict());
        assert!(config.get_validate());

        config.set_strict(false);
        config.set_validate(true);
        config.set_validate_allow_trailing_bytes(true);
        assert!(!config.get_strict());
        assert!(config.get_validate());
        assert!(config.get_validate_allow_trailing_bytes());
        config.set_validate_allow_trailing_bytes(false);
        assert!(!config.get_strict());
        assert!(config.get_validate());
        assert!(!config.get_validate_allow_trailing_bytes());
    }

    #[test]
    fn validate_allow_trailing_bytes_accepts_encoded_prefixes() {
        fn check<T: SolType>(value: &T::RustType)
        where
            T::RustType: PartialEq + core::fmt::Debug,
            for<'de> T::Token<'de>: TokenSeq<'de>,
        {
            type Encode<T> = fn(&<T as SolType>::RustType) -> Vec<u8>;
            type Decode<T> = fn(&[u8], AbiDecoderConfig) -> Result<<T as SolType>::RustType>;
            let codecs: [(Encode<T>, Decode<T>); 3] = [
                (T::abi_encode, T::abi_decode_with_config),
                (T::abi_encode_params, |data, config| {
                    T::abi_decode_params_with_config(data, config)
                }),
                (T::abi_encode_sequence, |data, config| {
                    T::abi_decode_sequence_with_config(data, config)
                }),
            ];
            for (encode, decode) in codecs {
                for suffix in [&[][..], &[0xff][..], &[0xaa; 32][..], &[0xbb; 33][..]] {
                    let mut encoded = encode(value);
                    encoded.extend_from_slice(suffix);
                    for config in [
                        AbiDecoderConfig::new().validate(true),
                        AbiDecoderConfig::new().validate(true).validate_allow_trailing_bytes(true),
                        AbiDecoderConfig::new().validate_allow_trailing_bytes(true),
                        AbiDecoderConfig::new().strict(true).validate_allow_trailing_bytes(true),
                        AbiDecoderConfig::new().validate_allow_trailing_bytes(true).strict(true),
                    ] {
                        assert_eq!(&decode(&encoded, config).unwrap(), value);
                    }
                    if !suffix.is_empty() {
                        assert_eq!(
                            decode(&encoded, AbiDecoderConfig::new().strict(true)),
                            Err(Error::ReserMismatch),
                        );
                    }
                }
            }
        }

        check::<()>(&());
        check::<(sol_data::Uint<8>, sol_data::Bool)>(&(42, true));
        check::<(sol_data::Bytes, sol_data::Array<sol_data::String>)>(&(
            bytes!("1234"),
            vec!["hello".into(), alloc::string::String::new()],
        ));
        check::<(sol_data::Array<sol_data::Bytes>,)>(&(vec![],));
    }

    #[test]
    fn validate_allow_trailing_bytes_keeps_other_checks() {
        let config = AbiDecoderConfig::new().strict(true).validate_allow_trailing_bytes(true);
        let value = bytes!("1122");
        let canonical = sol_data::Bytes::abi_encode(&value);

        // A suffix cannot substitute for required padding or payload bytes.
        for len in [canonical.len() - 1, 65] {
            assert_eq!(
                sol_data::Bytes::abi_decode_with_config(&canonical[..len], config),
                Err(Error::Overrun),
            );
        }
        let mut dirty_padding = canonical.clone();
        dirty_padding[66] = 1;
        dirty_padding.push(0xff);
        assert_eq!(
            sol_data::Bytes::abi_decode_with_config(&dirty_padding, config),
            Err(Error::ReserMismatch),
        );

        let mut gap = canonical;
        gap[31] = 64;
        gap.splice(32..32, [0; 32]);
        assert_eq!(
            sol_data::Bytes::abi_decode_with_config(&gap, config),
            Err(Error::ReserMismatch),
        );

        type Pair = (sol_data::Bytes, sol_data::Bytes);
        let mut overlap = Pair::abi_encode_params(&(value.clone(), value));
        overlap[63] = overlap[31];
        assert_eq!(
            Pair::abi_decode_params_with_config(&overlap, config),
            Err(Error::ReserMismatch)
        );

        let mut invalid_bool = Word::with_last_byte(2).to_vec();
        invalid_bool.push(0xff);
        assert!(sol_data::Bool::abi_decode_with_config(&invalid_bool, config).is_err());

        let mut invalid_string = sol_data::Bytes::abi_encode(&bytes!("ff"));
        invalid_string.push(0xff);
        assert!(sol_data::String::abi_decode_with_config(&invalid_string, config).is_err());
    }

    #[test]
    fn child_drop_keeps_the_furthest_strict_offset() {
        let decoder = Decoder::with_config(&[0; 192], AbiDecoderConfig::new().strict(true));
        let mut first = decoder.child(64).unwrap();
        let mut second = decoder.child(128).unwrap();
        first.take_word().unwrap();
        second.take_word().unwrap();

        drop(second);
        drop(first);

        assert_eq!(decoder.state.strict_next_offset().get(), 160);
    }

    #[test]
    fn exhausted_decoder_debug_does_not_panic() {
        let mut decoder = Decoder::new(&[0; 32]);
        decoder.take_word().unwrap();
        assert!(!format!("{decoder:?}").is_empty());
    }

    #[test]
    fn configured_decoder_validation() {
        let encoded = B256::repeat_byte(0x11);
        assert!(
            sol_data::Bool::abi_decode_with_config(encoded.as_slice(), AbiDecoderConfig::new())
                .is_ok()
        );
        assert!(
            sol_data::Bool::abi_decode_with_config(
                encoded.as_slice(),
                AbiDecoderConfig::new().validate(true),
            )
            .is_err()
        );
        assert!(
            sol_data::Bool::abi_decode_with_config(
                encoded.as_slice(),
                AbiDecoderConfig::new().strict(true),
            )
            .is_err()
        );
    }

    #[test]
    fn strict_decoder_rejects_noncanonical_bool() {
        let encoded = Word::with_last_byte(2);

        assert_eq!(sol_data::Bool::abi_decode(encoded.as_slice()), Ok(true));
        assert!(
            sol_data::Bool::abi_decode_with_config(
                encoded.as_slice(),
                AbiDecoderConfig::new().validate(true),
            )
            .is_err()
        );
        assert!(
            sol_data::Bool::abi_decode_with_config(
                encoded.as_slice(),
                AbiDecoderConfig::new().strict(true),
            )
            .is_err()
        );
    }

    #[test]
    fn strict_decoder_rejects_overlapping_nested_offsets() {
        type Ty = sol_data::Array<sol_data::Bytes>;

        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000020" // array offset
            "0000000000000000000000000000000000000000000000000000000000000002" // array length
            "0000000000000000000000000000000000000000000000000000000000000040" // first bytes offset
            "0000000000000000000000000000000000000000000000000000000000000040" // second bytes offset
            "0000000000000000000000000000000000000000000000000000000000000001" // bytes length
            "1100000000000000000000000000000000000000000000000000000000000000"
        );

        assert_eq!(Ty::abi_decode(&encoded).unwrap(), vec![bytes![0x11u8; 1], bytes![0x11u8; 1]]);
        assert_eq!(
            Ty::abi_decode_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn strict_decoder_accepts_canonical_offsets() {
        type Ty = (sol_data::Bytes, sol_data::Bytes);

        let value = (bytes![0x11u8, 0x22], bytes![0x33u8, 0x44]);
        let encoded = Ty::abi_encode_params(&value);

        assert_eq!(
            Ty::abi_decode_params_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Ok(value),
        );
    }

    #[test]
    fn strict_decoder_accepts_static_composites_around_dynamic_fields() {
        type Uint = sol_data::Uint<256>;
        type StaticTuple = (Uint, Uint);
        type StaticArray = sol_data::FixedArray<StaticTuple, 2>;
        type Ty = (StaticTuple, sol_data::Bytes, StaticArray, sol_data::Bytes);

        let value = (
            (U256::from(1), U256::from(2)),
            bytes![0x11u8; 1],
            [(U256::from(3), U256::from(4)), (U256::from(5), U256::from(6))],
            bytes![0x22u8; 1],
        );
        let encoded = Ty::abi_encode_params(&value);

        assert_eq!(
            Ty::abi_decode_params_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Ok(value),
        );
    }

    #[test]
    fn strict_decoder_accepts_dynamic_array_sequence() {
        type Ty = sol_data::Array<sol_data::Bytes>;

        let value = vec![bytes![0x11u8; 1], bytes!("2233")];
        let encoded = Ty::abi_encode(&value);

        assert_eq!(
            Ty::abi_decode_sequence_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Ok(value),
        );
    }

    #[test]
    fn strict_decoder_accepts_dynamic_fixed_array_sequence() {
        type Ty = sol_data::FixedArray<sol_data::Bytes, 2>;

        let value = [bytes![0x11u8; 1], bytes!("2233")];
        let encoded = Ty::abi_encode_sequence(&value);

        assert_eq!(
            Ty::abi_decode_sequence_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Ok(value),
        );
    }

    #[test]
    fn strict_decoder_accepts_empty_dynamic_sequences() {
        type Fixed = sol_data::FixedArray<sol_data::Bytes, 0>;

        let fixed: [alloy_primitives::Bytes; 0] = [];
        let encoded = Fixed::abi_encode(&fixed);
        assert_eq!(
            Fixed::abi_decode_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Ok(fixed),
        );

        type Dynamic = sol_data::Array<()>;

        let dynamic = vec![];
        let encoded = Dynamic::abi_encode(&dynamic);
        assert_eq!(
            Dynamic::abi_decode_sequence_with_config(
                &encoded,
                AbiDecoderConfig::new().strict(true)
            ),
            Ok(dynamic),
        );
    }

    #[test]
    fn strict_decoder_rejects_nonempty_zero_sized_dynamic_arrays() {
        type Ty = sol_data::Array<()>;

        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000020"
            "0000000000000000000000000000000000000000000000000000000000000001"
        );

        assert_eq!(Ty::abi_decode_sequence(&encoded), Ok(vec![()]));
        assert_eq!(
            Ty::abi_decode_sequence_with_config(&encoded, AbiDecoderConfig::new().memory_limit(0)),
            Err(Error::MemoryLimitExceeded(0)),
        );
        assert_eq!(
            Ty::abi_decode_sequence_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn strict_decoder_checks_dynamic_elements_before_reserving_the_outer_array() {
        type Ty = sol_data::Array<sol_data::FixedArray<sol_data::Bytes, 64>>;

        let mut encoded = Vec::with_capacity(32 * 66);
        encoded.extend_from_slice(pad_usize(32).as_slice());
        encoded.extend_from_slice(pad_usize(1).as_slice());
        encoded.resize(32 * 66, 0);

        assert_eq!(
            Ty::abi_decode_sequence_with_config(
                &encoded,
                AbiDecoderConfig::new().memory_limit(0).strict(true),
            ),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn strict_decoder_rejects_gapped_offsets() {
        type Ty = (sol_data::String, sol_data::String);

        let value = ("one".to_string(), "two".to_string());
        let mut encoded = Ty::abi_encode(&value);
        encoded[95] = 0xa0;
        encoded.splice(160..160, [0; 32]);

        assert_eq!(Ty::abi_decode(&encoded), Ok(value));
        assert_eq!(
            Ty::abi_decode_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn strict_decoder_rejects_trailing_data() {
        type Ty = (sol_data::Bytes, sol_data::Bytes);

        let value = (bytes![0x11u8; 1], bytes![0x22u8; 1]);
        let mut encoded = Ty::abi_encode_params(&value);
        encoded.extend([0; 32]);

        assert_eq!(Ty::abi_decode_params(&encoded), Ok(value));
        assert_eq!(
            Ty::abi_decode_params_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn strict_decoder_accepts_nested_encoder_output() {
        type Ty = (
            sol_data::String,
            sol_data::Array<sol_data::Array<sol_data::Address>>,
            sol_data::Bytes,
        );

        let value = (
            "strict".to_string(),
            vec![vec![Address::repeat_byte(0x11)], vec![Address::repeat_byte(0x22)]],
            bytes!("beef"),
        );
        let encoded = Ty::abi_encode(&value);

        assert_eq!(
            Ty::abi_decode_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Ok(value),
        );
    }

    #[test]
    fn strict_decoder_rejects_nonzero_padding() {
        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000020"
            "0000000000000000000000000000000000000000000000000000000000000001"
            "11ff000000000000000000000000000000000000000000000000000000000000"
        );

        assert_eq!(sol_data::Bytes::abi_decode(&encoded).unwrap(), bytes![0x11u8; 1]);
        assert_eq!(
            sol_data::Bytes::abi_decode_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn strict_decoder_rejects_overlapping_bytes_offsets() {
        type Ty = (sol_data::Bytes, sol_data::Bytes);

        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000040" // first bytes offset
            "0000000000000000000000000000000000000000000000000000000000000040" // second bytes offset
            "0000000000000000000000000000000000000000000000000000000000000003" // bytes length
            "1122330000000000000000000000000000000000000000000000000000000000"
        );

        assert_eq!(
            Ty::abi_decode_params(&encoded).unwrap(),
            (bytes![0x11u8, 0x22, 0x33], bytes![0x11u8, 0x22, 0x33]),
        );
        assert_eq!(
            Ty::abi_decode_params_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn strict_decoder_rejects_overlapping_dynamic_array_offsets() {
        type Ty = (sol_data::Array<sol_data::Uint<256>>, sol_data::Array<sol_data::Uint<256>>);

        let encoded = hex!(
            "0000000000000000000000000000000000000000000000000000000000000040" // first array offset
            "0000000000000000000000000000000000000000000000000000000000000040" // second array offset
            "0000000000000000000000000000000000000000000000000000000000000002" // array length
            "0000000000000000000000000000000000000000000000000000000000000001"
            "0000000000000000000000000000000000000000000000000000000000000002"
        );

        assert_eq!(
            Ty::abi_decode_params(&encoded).unwrap(),
            (vec![U256::from(1), U256::from(2)], vec![U256::from(1), U256::from(2)]),
        );
        assert_eq!(
            Ty::abi_decode_params_with_config(&encoded, AbiDecoderConfig::new().strict(true)),
            Err(Error::ReserMismatch),
        );
        assert_eq!(
            Ty::abi_decode_params_with_config(&encoded, AbiDecoderConfig::new().memory_limit(64)),
            Err(Error::MemoryLimitExceeded(64)),
        );
        assert_eq!(
            Ty::abi_decode_params_with_config(
                &encoded,
                AbiDecoderConfig::new().memory_limit(64).strict(true),
            ),
            Err(Error::ReserMismatch),
        );
    }

    #[test]
    fn configured_decoder_enforces_memory_limit() {
        type Ty = sol_data::Array<sol_data::Uint<256>>;

        let encoded = Ty::abi_encode(&vec![U256::ZERO]);
        let err = decode_sequence_with_config::<<Ty as SolType>::Token<'_>>(
            &encoded,
            AbiDecoderConfig::new().memory_limit(31),
        )
        .unwrap_err();
        assert_eq!(err, Error::MemoryLimitExceeded(31));
    }

    #[test]
    fn direct_decoder_enforces_memory_limit() {
        type Ty = sol_data::Array<sol_data::Uint<256>>;

        let encoded = Ty::abi_encode(&vec![U256::ZERO]);
        let mut decoder = Decoder::with_config(&encoded, AbiDecoderConfig::new().memory_limit(31));
        let err = decoder.decode::<<Ty as SolType>::Token<'_>>().unwrap_err();
        assert_eq!(err, Error::MemoryLimitExceeded(31));
    }

    #[test]
    fn child_decoder_borrows_parent_state() {
        type Ty = sol_data::Array<sol_data::Uint<256>>;

        let encoded = Ty::abi_encode(&vec![U256::ZERO]);
        let decoder = Decoder::with_config(&encoded, AbiDecoderConfig::new().memory_limit(31));
        let mut child = decoder.child(0).unwrap();
        let err = child.decode::<<Ty as SolType>::Token<'_>>().unwrap_err();
        assert_eq!(err, Error::MemoryLimitExceeded(31));
    }

    #[test]
    fn configured_decoder_tracks_child_allocations() {
        type Ty = sol_data::Array<sol_data::Array<sol_data::Uint<256>>>;

        let encoded = Ty::abi_encode(&vec![vec![U256::ZERO], vec![U256::ZERO]]);
        let err = decode_sequence_with_config::<<Ty as SolType>::Token<'_>>(
            &encoded,
            AbiDecoderConfig::new().memory_limit(100),
        )
        .unwrap_err();
        assert_eq!(err, Error::MemoryLimitExceeded(100));
    }

    #[test]
    fn configured_decoder_tracks_recursive_allocations() {
        type Uint = sol_data::Uint<256>;
        type Inner = sol_data::Array<Uint>;
        type Middle = sol_data::Array<Inner>;
        type Ty = sol_data::Array<Middle>;

        let value = vec![vec![vec![U256::ZERO]], vec![vec![U256::ZERO]]];
        let encoded = Ty::abi_encode(&value);
        let memory_used = 2 * core::mem::size_of::<<Middle as SolType>::Token<'_>>()
            + 2 * core::mem::size_of::<<Inner as SolType>::Token<'_>>()
            + 2 * core::mem::size_of::<<Uint as SolType>::Token<'_>>();

        decode_sequence_with_config::<<Ty as SolType>::Token<'_>>(
            &encoded,
            AbiDecoderConfig::new().memory_limit(memory_used),
        )
        .unwrap();
        let err = decode_sequence_with_config::<<Ty as SolType>::Token<'_>>(
            &encoded,
            AbiDecoderConfig::new().memory_limit(memory_used - 1),
        )
        .unwrap_err();
        assert_eq!(err, Error::MemoryLimitExceeded(memory_used - 1));
    }

    #[test]
    fn configured_decoder_tracks_aliased_tuple_allocations() {
        sol! {
            struct Rule {
                bytes4 selector;
                address[] recipients;
            }

            struct Scope {
                address target;
                Rule[] rules;
            }

            function apply(address account, Scope[] scopes);
        }

        fn word(value: usize) -> [u8; 32] {
            let mut out = [0_u8; 32];
            out[24..].copy_from_slice(&(value as u64).to_be_bytes());
            out
        }

        fn aliased_call_data(width: usize) -> Vec<u8> {
            let mut data = Vec::with_capacity(292 + 96 * width);
            data.extend(applyCall::SELECTOR);

            data.extend(word(0));
            data.extend(word(64));

            data.extend(word(width));
            for _ in 0..width {
                data.extend(word(width * 32));
            }

            data.extend(word(1));
            data.extend(word(64));

            data.extend(word(width));
            for _ in 0..width {
                data.extend(word(width * 32));
            }

            let mut selector = [0_u8; 32];
            selector[..4].copy_from_slice(&[0xde, 0xad, 0xbe, 0xef]);
            data.extend(selector);
            data.extend(word(64));

            data.extend(word(width));
            for i in 0..width {
                data.extend(word(i + 1));
            }

            assert_eq!(data.len(), 292 + 96 * width);
            data
        }

        type Address = sol_data::Address;

        let width = 2_usize;
        let data = aliased_call_data(width);
        let memory_used = width * core::mem::size_of::<<Scope as SolType>::Token<'_>>()
            + width.pow(2) * core::mem::size_of::<<Rule as SolType>::Token<'_>>()
            + width.pow(3) * core::mem::size_of::<<Address as SolType>::Token<'_>>();

        applyCall::abi_decode_with_config(&data, AbiDecoderConfig::new().memory_limit(memory_used))
            .unwrap();
        let err = match applyCall::abi_decode_with_config(
            &data,
            AbiDecoderConfig::new().memory_limit(memory_used - 1),
        ) {
            Ok(_) => panic!("decoding should exceed the memory limit"),
            Err(err) => err,
        };
        assert_eq!(err, Error::MemoryLimitExceeded(memory_used - 1));

        let strict_memory_used = width
            * (core::mem::size_of::<<Scope as SolType>::Token<'_>>()
                + core::mem::size_of::<<Rule as SolType>::Token<'_>>()
                + core::mem::size_of::<<Address as SolType>::Token<'_>>());
        let err = match applyCall::abi_decode_with_config(
            &data,
            AbiDecoderConfig::new().memory_limit(strict_memory_used).strict(true),
        ) {
            Ok(_) => panic!("strict decoding should reject aliased offsets"),
            Err(err) => err,
        };
        assert_eq!(err, Error::ReserMismatch);
    }

    #[test]
    fn configured_decoder_enforces_recursion_limit() {
        type Ty = sol_data::Array<sol_data::Uint<256>>;

        let encoded = Ty::abi_encode(&vec![U256::ZERO]);
        let err = decode_sequence_with_config::<<Ty as SolType>::Token<'_>>(
            &encoded,
            AbiDecoderConfig::new().recursion_limit(0),
        )
        .unwrap_err();
        assert_eq!(err, Error::RecursionLimitExceeded(0));
    }
}