bug: serialize & writeJson are not deterministic

[OliverNChalk]

Component

Forge

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (06f7c9c 2023-03-18T00:08:48.50351195Z)

What command(s) is the bug in?

No response

Operating System

Linux

Describe the bug

I would expect that writeJson and related cheatcodes would produce a deterministic result. However, across runs this output will be different:

This code:

    function _deployerMetadata() private returns (string memory rDeployerMetadata) {
        string memory lObjectKey = "qwerty";

        vm.serializeBytes32(lObjectKey, "factory_hash", keccak256(type(GenericFactory).creationCode));
        vm.serializeBytes32(lObjectKey, "constant_product_hash", keccak256(type(ConstantProductPair).creationCode));
        vm.serializeBytes32(lObjectKey, "stable_hash", keccak256(type(StablePair).creationCode));
        rDeployerMetadata = vm.serializeBytes32(lObjectKey, "oracle_caller_hash", keccak256(type(OracleCaller).creationCode));
    }

    // SNIP

    vm.writeJson(
        _deployerMetadata(),
        "scripts/unoptimized-deployer-meta"
    );

Produces:

{
  "oracle_caller_hash": "0x262458524d9c8928fe7fd7661236b93f6d6a9535182f48fd582a75f18bfbf85f",
  "constant_product_hash": "0x043551969376243d49aff4ce627e029219c6d90e16c780a7d2ef4f72b6fcf236",
  "factory_hash": "0x67de66ba417a88060e4b7b0cde0d56b01973a4b9f0066385ba661c58d2d6ca50",
  "stable_hash": "0x3239f5ad44712803a6036e7a99f6fdfb9f98f22d8e39ebff8de3c1996ab5dfec"
}

OR:

{
  "oracle_caller_hash": "0x262458524d9c8928fe7fd7661236b93f6d6a9535182f48fd582a75f18bfbf85f",
  "constant_product_hash": "0x043551969376243d49aff4ce627e029219c6d90e16c780a7d2ef4f72b6fcf236",
  "stable_hash": "0x3239f5ad44712803a6036e7a99f6fdfb9f98f22d8e39ebff8de3c1996ab5dfec",
  "factory_hash": "0x67de66ba417a88060e4b7b0cde0d56b01973a4b9f0066385ba661c58d2d6ca50"
}

And so forth. I imagine it should be possible to serialize the keys in alphabetical order, though not sure if this will need to be custom implemented or can be easily done with serde_json::Value

[sakulstra]

Hey, i'm still facing this issue on latest nightly - probably i'm doing sth slightly different though as i'm working with nested objects.

When i do sth like:

function repro() internal {
    string memory content;

    for (uint256 i = 0; i < 2; i++) {
        string memory key = vm.toString(i);
        vm.serializeUint(key, 'a', 100);
        string memory object = vm.serializeUint(key, 'b', 200);
        content = vm.serializeString(eModesKey, key, object);
      }
    }
    string memory output = vm.serializeString('root', 'category', content);
    vm.writeJson(output, path);
  }

The output will alternate between:

{
  category: {
    0: {a: 100, b: 200},
    1: {a: 100, b: 200}
  }
}

and

{
  category: {
    1: {a: 100, b: 200},
    0: {a: 100, b: 200}
  }
}

https://github.com/bgd-labs/aave-helpers/blob/master/src/ProtocolV3TestBase.sol#L255-L283

[mds1]

cc @odyslam, added this to #3801 (comment)