This is an experience post

[Mengbuxiu]

Im learning Foundry cast send/call, and I got an error, so I search the error by AI.

这是我的合约代码

// I'm a comment!
// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

// pragma solidity ^0.8.0;
// pragma solidity >=0.8.0 <0.9.0;

contract SimpleStorage {
    uint256 myFavoriteNumber;

    struct Person {
        uint256 favoriteNumber;
        string name;
    }
    // uint256[] public anArray;
    Person[] public listOfPeople;

    mapping(string => uint256) public nameToFavoriteNumber;

    function store(uint256 _favoriteNumber) public {
        myFavoriteNumber = _favoriteNumber;
    }

    function retrieve() public view returns (uint256) {
        return myFavoriteNumber;
    }

    function addPerson(string memory _name, uint256 _favoriteNumber) public {
        listOfPeople.push(Person(_favoriteNumber, _name));
        nameToFavoriteNumber[_name] = _favoriteNumber;
    }
}

这是测试参数传入

moss@PC-202211051618:~/foundry-f23/foundry-simple-storage-f23$ cast send 0x700b6a60ce
7eaaea56f065753d8dcb9653dbad35 "store(uint256)" 123 --rpc-url $RPC_URL --private-key $PRIVATE_KEY

blockHash            0xb87c424de377722b4d532b6ec4f94e045941bc9f22a0dcb6a1dd29a42e60e8ab
blockNumber          2
contractAddress      
cumulativeGasUsed    21204
effectiveGasPrice    875176701
from                 0xa0Ee7A142d267C1f36714E4a8F75612F20a79720
gasUsed              21204
logs                 []
logsBloom            0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
root                 
status               1 (success)
transactionHash      0x5a79cda6552eb494f21c99e80c25ec8e019bc515717cd22b4bf94cb156ef76e4
transactionIndex     0
type                 2
blobGasPrice         1
blobGasUsed          
authorizationList    
to                   0x700b6A60ce7EaaEA56F065753d8dcB9653dbAD35

这是测试调用

moss@PC-202211051618:~/foundry-f23/foundry-simple-storage-f23$ cast call 0x700b6a60ce
7eaaea56f065753d8dcb9653dbad35 "retrieve()"

最后返回了
0x

Ai gave me the answer: I requested a invalid contract address, and I fix it.
and other question appear
Why did I receive a success response when I requested an invalid contract address?

for example(The following is the correct implementation and verification, which is just an example)

moss@PC-202211051618:~/foundry-f23/foundry-simple-storage-f23$ cast send 0xe1Aa25618fA0c7A1CFDab5d6B456af611873b629 "store(uint256)" 123 --rpc-url http://localhost:8545 --private-key $PRIVATE_KEY

blockHash            0x4dbe64c97d400f0cef79eb96e30570d29c15376455ba7395e3355de3afdc54b2
blockNumber          6
contractAddress      
cumulativeGasUsed    43746
effectiveGasPrice    516074198
from                 0xa0Ee7A142d267C1f36714E4a8F75612F20a79720
gasUsed              43746
logs                 []
logsBloom            0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
root                 
status               1 (success)
transactionHash      0x6e019b73189b7b79022f5acecc891e5762b597211457ba3f6088c6dc68791313
transactionIndex     0
type                 2
blobGasPrice         1
blobGasUsed          
authorizationList    
to                   0xe1Aa25618fA0c7A1CFDab5d6B456af611873b629
moss@PC-202211051618:~/foundry-f23/foundry-simple-storage-f23$ cast storage 0xe1Aa25618fA0c7A1CFDab5d6B456af611873b629  0 --rpc-url $RPC_URL
0x000000000000000000000000000000000000000000000000000000000000007b
moss@PC-202211051618:~/foundry-f23/foundry-simple-storage-f23$ cast call 0xe1Aa25618fA0c7A1CFDab5d6B456af611873b629 "retrieve()" --rpc-url http://localhost:8545
0x000000000000000000000000000000000000000000000000000000000000007b

moss@PC-202211051618:~/foundry-f23/foundry-simple-storage-f23$ cast --to-base 0x000000000000000000000000000000000000000000000000000000000000007b dec
123

The following is the answer given by AI. I think it is worth learning, so I share it here.

在以太坊中，交易成功（status=1）只表示交易被正确执行，没有回滚，但并不意味着目标合约的函数按预期工作。

🔍 ​具体原因分析（以你的案例为例）​

1. ​地址被截断后的巧合

• 你输入的地址 0xe1Aa25618fA0c7A1CFD 被换行截断后，实际可能被系统解析为 0xe1Aa25618fA0c7A1CFD（仅20字节中的前部分），此时：
• ​情况一：若该地址是外部账户（EOA）​​（无合约代码），调用 store(123) 会触发空交易（相当于转账），但无代码执行，因此状态仍为成功（因为没有revert）。
• ​情况二：若该地址恰好是其他合约，且其代码未在调用中回滚，交易也会显示成功。

2. ​交易成功 ≠ 状态改变

• status:1 仅表示：
• 交易格式正确。
• Gas足够支付执行成本。
• 未触发 revert。
• ​但无法保证：
• 目标地址是你要调用的合约。
• 函数实际修改了预期的状态变量。

3. ​函数调用的特殊性

• 当向外部账户（EOA）​发送带有数据的交易时：
• 数据（如 store(uint256)）会被忽略，交易视为普通转账。
• 由于无代码执行，不会触发错误，因此状态为成功。

---

🧩 ​你的案例还原
1.​
执行 cast send 时：

• 输入地址被截断为 0xe1Aa25618fA0c7A1CFD（假设实际解析为一个外部账户地址）。
• 交易被当作向该地址发送0 ETH的转账，附带数据 store(uint256) 123。
• 由于外部账户无法处理数据，数据被忽略，但交易本身合法，因此 status:1。
  2.​
  执行 cast call retrieve() 时：
• 调用无效地址的 retrieve()，由于目标地址无合约代码，返回 0x（空数据）。

---

✅ ​正确验证方法

1. ​检查交易详情
   bashcast receipt <TRANSACTION_HASH> --rpc-url $RPC_URL

• 确认 to 字段地址是否与预期合约地址一致。
• 观察 logs 是否有预期事件（若合约触发事件）。

2. ​直接验证合约状态
   bash# 查看存储槽0（对应 myFavoriteNumber）
   cast storage 0xe1Aa25618fA0c7A1CFDab5d6B456af611873b629 0 --rpc-url $RPC_URL

• 预期返回 0x000000000000000000000000000000000000000000000000000000000000007b（123的十六进制）。

3. ​检查合约代码是否存在
   bashcast code 0xe1Aa25618fA0c7A1CFDab5d6B456af611873b629 --rpc-url $RPC_URL

• 若返回非 0x，说明合约已部署。

---

📝 ​总结

• ​交易成功（status=1）不保证目标地址有效或函数逻辑正确，它只反映交易本身的执行合规性。
• ​调用无效地址可能“成功”，因为它可能指向外部账户或无冲突的其他合约。
• ​务必验证地址完整性和合约状态，避免因输入错误导致逻辑错觉。

---

通过严格检查地址输入和合约状态，你可以避免此类“看似成功实则无效”的问题！

[EngrPips]

Hello @Mengbuxiu, Here https://book.getfoundry.sh/cast/ you can read about the Foundry Cast to learn more about the feature and how it works

[chainflash]

Nice

[Mengbuxiu]

thx.I fix the error and i have some ideas, so I post here.

[EngrPips]

Awesome, Keep crushing it.