Non-dynamic, fixed-length array encoding is broken

[coinop-logan]

If a contract has a function that takes an argument like uint[6], the binding generated for that function just takes a single uint argument for the entire array and encodes it where the array would go.

Currently I can get around this by just adding in all the arguments I need in the Elm binding, and encoding them all sequentially.

Here's some example code...

Solidity function:

function openToastytrade(address payable _initiator, bool initiatorIsBuyer, uint[6] calldata uintArgs, string calldata _totalPrice, string calldata _fiatTransferMethods, string calldata _commPubkey)
external
returns (Toastytrade) {
    ....
}

ABI entry for that function:

   {
        "constant": false,
        "inputs": [
            {
                "name": "_initiator",
                "type": "address"
            },
            {
                "name": "initiatorIsBuyer",
                "type": "bool"
            },
            {
                "name": "uintArgs",
                "type": "uint256[6]"
            },
            {
                "name": "_totalPrice",
                "type": "string"
            },
            {
                "name": "_fiatTransferMethods",
                "type": "string"
            },
            {
                "name": "_commPubkey",
                "type": "string"
            }
        ],
        "name": "openToastytrade",
        "outputs": [
            {
                "name": "",
                "type": "address"
            }
        ],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "function"
    }

Generated Elm binding:

openToastytrade : Address -> Address -> Bool -> BigInt -> String -> String -> String -> Call Address
openToastytrade contractAddress initiator initiatorIsBuyer uintArgs totalPrice fiatTransferMethods commPubkey =
    { to = Just contractAddress
    , from = Nothing
    , gas = Nothing
    , gasPrice = Nothing
    , value = Nothing
    , data = Just <| AbiEncode.functionCall "openToastytrade(address,bool,uint256[6],string,string,string)" [ AbiEncode.address initiator, AbiEncode.bool initiatorIsBuyer, AbiEncode.uint uintArgs, string-UNSUPPORTED-plz-open-github-issue totalPrice, string-UNSUPPORTED-plz-open-github-issue fiatTransferMethods, string-UNSUPPORTED-plz-open-github-issue commPubkey ]
    , nonce = Nothing
    , decoder = toElmDecoder AbiDecode.address
    }

Obviously that won't take all the info I need to pass, so I then change that to:

openToastytrade : Address -> Address -> Bool -> BigInt -> BigInt -> BigInt -> BigInt -> BigInt -> BigInt -> String -> String -> String -> Call Address
openToastytrade contractAddress initiator initiatorIsBuyer uintArg1 uintArg2 uintArg3 uintArg4 uintArg5 uintArg6 totalPrice fiatTransferMethods commPubkey =
    { to = Just contractAddress
    , from = Nothing
    , gas = Nothing
    , gasPrice = Nothing
    , value = Nothing
    , data = Just <| AbiEncode.functionCall "openToastytrade(address,bool,uint256[6],string,string,string)" 
        [ AbiEncode.address initiator, AbiEncode.bool initiatorIsBuyer, AbiEncode.uint uintArg1, AbiEncode.uint uintArg2, AbiEncode.uint uintArg3, AbiEncode.uint uintArg4, AbiEncode.uint uintArg5, AbiEncode.uint uintArg6, string-UNSUPPORTED-plz-open-github-issue totalPrice, string-UNSUPPORTED-plz-open-github-issue fiatTransferMethods, string-UNSUPPORTED-plz-open-github-issue commPubkey ]
    , nonce = Nothing
    , decoder = toElmDecoder AbiDecode.address
    }

which seems to work without issue--not too surprising, because a fixed-length array of static values is just encoded sequentially: https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#argument-encoding

[coinop-logan]

By the way, I tried using AbiEncode.list (List.map AbiEncode.uint listOfUintArgs), and that failed to encode correctly. Not sure if that's a bug or I just don't understand what AbiEncode.list is supposed to be used for.

[cmditch]

@coinop-logan Was this related to the tillMod64 bug?

cmditch/elm-ethereum@ad35d0d#diff-1be9f4f724b980b8a832cdc09b856da1R704