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xJonathanLEIxJonathanLEI
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feat: ByteArray type (#682)
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‎starknet-core/src/types/byte_array.rs

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,222 @@
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use alloc::{string::*, vec::*};
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use num_traits::ToPrimitive;
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use crate::{
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codec::{Decode, Encode, Error as CodecError, FeltWriter},
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types::Felt,
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};
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const BYTES_PER_SLOT: usize = 31;
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const FELT_BYTE_SIZE: usize = 32;
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/// The `ByteArray` type in Cairo.
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#[derive(Debug, Clone, PartialEq, Eq)]
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pub struct ByteArray(Vec<u8>);
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impl ByteArray {
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/// Returns the number of bytes in the array, also referred to as its 'length'.
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pub fn len(&self) -> usize {
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self.0.len()
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}
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/// Returns `true` if the array contains no bytes.
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#[must_use]
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pub fn is_empty(&self) -> bool {
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self.0.is_empty()
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}
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}
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impl From<Vec<u8>> for ByteArray {
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fn from(value: Vec<u8>) -> Self {
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Self(value)
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}
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}
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impl From<&str> for ByteArray {
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fn from(value: &str) -> Self {
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Self(value.as_bytes().to_vec())
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}
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}
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impl From<ByteArray> for Vec<u8> {
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fn from(value: ByteArray) -> Self {
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value.0
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}
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}
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impl TryFrom<ByteArray> for String {
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type Error = FromUtf8Error;
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fn try_from(value: ByteArray) -> Result<Self, Self::Error> {
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Self::from_utf8(value.0)
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}
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}
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impl Encode for ByteArray {
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fn encode<W: FeltWriter>(&self, writer: &mut W) -> Result<(), CodecError> {
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writer.write((self.len() / BYTES_PER_SLOT).into());
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let mut chunks_iter = self.0.chunks_exact(BYTES_PER_SLOT);
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for full_slot in chunks_iter.by_ref() {
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writer.write(Felt::from_bytes_be_slice(full_slot));
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}
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let last_chunk = chunks_iter.remainder();
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writer.write(Felt::from_bytes_be_slice(last_chunk));
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writer.write(last_chunk.len().into());
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Ok(())
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}
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}
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impl<'a> Decode<'a> for ByteArray {
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fn decode_iter<T>(iter: &mut T) -> Result<Self, CodecError>
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where
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T: Iterator<Item = &'a Felt>,
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{
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let length = iter.next().ok_or_else(CodecError::input_exhausted)?;
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let length = length
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.to_usize()
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.ok_or_else(|| CodecError::value_out_of_range(length, "usize"))?;
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let mut result = Vec::<u8>::with_capacity(length * BYTES_PER_SLOT + BYTES_PER_SLOT - 1);
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for _ in 0..length {
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let full_slot = iter.next().ok_or_else(CodecError::input_exhausted)?;
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result.extend_from_slice(&full_slot.to_bytes_be()[1..]);
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}
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let pending_word = iter.next().ok_or_else(CodecError::input_exhausted)?;
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let pending_word_len = iter.next().ok_or_else(CodecError::input_exhausted)?;
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let pending_word_len = pending_word_len
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.to_usize()
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.ok_or_else(|| CodecError::value_out_of_range(pending_word_len, "usize"))?;
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result
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.extend_from_slice(&pending_word.to_bytes_be()[(FELT_BYTE_SIZE - pending_word_len)..]);
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Ok(Self(result))
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
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fn test_string_encode_decode_roundtrip() {
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let test_data = [
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(
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"",
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vec![
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000000",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000000",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000000",
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),
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],
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),
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(
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"abc",
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vec![
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000000",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000616263",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000003",
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),
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],
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),
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(
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"000000000011111111112222222222",
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vec![
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000000",
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),
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Felt::from_hex_unchecked(
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"0x0000303030303030303030303131313131313131313132323232323232323232",
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),
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Felt::from_hex_unchecked(
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"0x000000000000000000000000000000000000000000000000000000000000001e",
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),
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],
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),
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(
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"0000000000111111111122222222223",
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vec![
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000001",
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),
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Felt::from_hex_unchecked(
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"0x0030303030303030303030313131313131313131313232323232323232323233",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000000",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000000",
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),
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],
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),
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(
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"00000000001111111111222222222233",
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vec![
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000001",
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),
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Felt::from_hex_unchecked(
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"0x0030303030303030303030313131313131313131313232323232323232323233",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000033",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000001",
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),
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],
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),
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(
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"00000000001111111111222222222233333333334444444444\
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55555555556666666666777777777788888888889999999999",
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vec![
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000003",
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),
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Felt::from_hex_unchecked(
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"0x0030303030303030303030313131313131313131313232323232323232323233",
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),
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Felt::from_hex_unchecked(
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"0x0033333333333333333334343434343434343434353535353535353535353636",
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),
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Felt::from_hex_unchecked(
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"0x0036363636363636363737373737373737373738383838383838383838393939",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000039393939393939",
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),
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Felt::from_hex_unchecked(
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"0x0000000000000000000000000000000000000000000000000000000000000007",
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),
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],
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),
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];
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for (string, expected) in test_data {
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let bytes: ByteArray = string.into();
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let mut encoded = vec![];
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bytes.encode(&mut encoded).unwrap();
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assert_eq!(encoded, expected);
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let decoded = ByteArray::decode(&expected).unwrap();
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assert_eq!(String::try_from(decoded).unwrap(), string);
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}
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}
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}

‎starknet-core/src/types/mod.rs

+3
Original file line numberDiff line numberDiff line change
@@ -65,6 +65,9 @@ pub use msg::MsgToL2;
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mod call;
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pub use call::Call;
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mod byte_array;
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pub use byte_array::ByteArray;
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// TODO: move generated request code to `starknet-providers`
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/// Module containing JSON-RPC request types.
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pub mod requests;

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