NestedStruct.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

struct InnerStruct {
    uint256 innerValue;
    bytes data;
}

struct OuterStruct {
    uint256 outerValue;
    InnerStruct inner;
}

contract NestedStructContract {
    OuterStruct public data;

    function bytes_encoded() public pure returns (bytes memory out) {
        out = abi.encode(OuterStruct(10e18, InnerStruct(10e18, bytes("hello solidity"))));
    }

    function decodeNestedStruct(bytes memory _data) public pure returns (OuterStruct memory) {
        return abi.decode(_data, (OuterStruct));
    }
}


///// FORGE TEST FILE /////

// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;

import "forge-std/Test.sol";
import "../src/test.sol";

contract EncodeDecodeTest is Test {
    NestedStructContract public nested;

    function setUp() public {
        nested = new NestedStructContract();
    }

    function testEncodeAndDecode() public view {
        bytes memory _data = nested.bytes_encoded();

        console.log(""); // this is to create a padding
        console.log("");
        console.log("");
        console.log("=============== Logging encoded nested struct ===============");
        console.logBytes(_data);
        console.log("=============== Logging encoded nested struct ends here ===============");
        console.log("");
        console.log("");
        console.log("");

        OuterStruct memory _value;

        _value = nested.decodeNestedStruct(_data);
        console.log("============== Decoding nested struct ==============");
        // console.log("");`
        console.logString(string(_value.inner.data)); // get string from nested struct
        console.log(_value.inner.innerValue);
        console.log(_value.outerValue);
    }
}