Nested array support

Hello -

Came here thanks to the helpful link at ethereum/web3.js#1137.

I was trying out the new experimental support for nested dynamical array in ABIEncoderV2.

Turns out there is currently no ABI decoder that supports it if I am not wrong.

Just wanted to open a ticket to make sure that this is also same with ethers.js.

Here is a quick test case I got:

Registry.sol

pragma solidity ^0.4.18;
pragma experimental SMTChecker;
pragma experimental ABIEncoderV2;

contract Registry {
	bool[][] matrix;

	function Registry() {
		bool[] memory test = new bool[](2);
		test[0] = true;
		test[1] = true;
		matrix.push(test);
	}
	function adjacency_matrix() constant returns (bool[][]) {
		return matrix;
	}
	function getLength() constant returns (uint length) {
		length = matrix.length;
	}
}

ethers-js.ts

import {Wallet, Contract, providers} from "ethers";
const wallet = new Wallet("0x8e6e5c8c3239e87ab550aa58d797c2c71355a1e4e2ef2342884a3462548b82d6", new providers.JsonRpcProvider(undefined, "development"));

const abi = [
	{
		"constant": true,
		"inputs": [],
		"name": "getLength",
		"outputs": [
			{
				"name": "length",
				"type": "uint256"
			}
		],
		"payable": false,
		"stateMutability": "view",
		"type": "function"
	},
	{
		"constant": true,
		"inputs": [],
		"name": "adjacency_matrix",
		"outputs": [
			{
				"name": "",
				"type": "bool[][]"
			}
		],
		"payable": false,
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [],
		"payable": false,
		"stateMutability": "nonpayable",
		"type": "constructor"
	}
];
const contract = new Contract("0x80446d11f150c883ab148b5c4014c3e859ff1662", abi, wallet);

const result = contract.adjacency_matrix();
result.then((res) => {console.log(res)}).catch((e) => {console.log(e)});

Result:

$ ts-node ethers-js.ts

{ Error: invalid type
    at throwError (/home/isaac/Development/truffle/node_modules/ethers-utils/throw-error.js:4:17)
    at getParamCoder (/home/isaac/Development/truffle/node_modules/ethers-contracts/interface.js:290:48)
    at /home/isaac/Development/truffle/node_modules/ethers-contracts/interface.js:587:21
    at Array.forEach (<anonymous>)
    at Function.decodeParams (/home/isaac/Development/truffle/node_modules/ethers-contracts/interface.js:586:11)
    at CallDescription.result.parse (/home/isaac/Development/truffle/node_modules/ethers-contracts/interface.js:406:50)
    at /home/isaac/Development/truffle/node_modules/ethers-contracts/contract.js:115:37
    at <anonymous>
    at process._tickDomainCallback (internal/process/next_tick.js:228:7) type: '' }

Will update this issue with further details. I will be looking into (1) creating a test case for this or even (2) contributing.

Thanks -Isaac

[ricmoo]

This is now supported in the encodeParams and decodeParams methods of Interface. I will soon get JSON support for naming the nested objects nicely. But for now you can do:

var params = [
    // Double-dynamic arrays
    "address[][]",
    "address[][3]",

    // Arrays of dynamic 
    "string[3]",
    "string[]",
    "bytes[4]",
    "bytes[]",

    // Tuples
    "tuple(address,tuple(uint256[],bool),int48)"
];
Interface.decodeParams(params, data);
Interface.encodeParams(params, values);

There are just over 2000 test cases compiled against a local PoA parity node located in tests/tests/contract-interface-abi2.json.gz that all pass. A small bug has been found in the v2 Solidity compiler (this is an experimental feature after all), and I’ve opened an issue, and they are looking into it. Once that is fixed there are a few more test cases that will be added to this coder.

[ricmoo]

Full support for decoding is now available. Encoding works for arrays, but not named items yet.