Is there a way to encode a struct?

Is there a way to encode a struct before passing it as a function argument? I want to be able to do it in JS, preferably using ethers. I couldn’t figure it out from the docs and past issues. Thank you for your help.

Let’s say this is my contract:

pragma solidity ^0.5.17;
pragma experimental ABIEncoderV2;

contract MyContract {

  struct MyStruct {
    address a;
    uint    b;
    bool    c;
  }

  function myFunction(bytes memory _data) public {

    MyStruct memory data = abi.decode(_data, (MyStruct));

    // Do stuff with data.a, data.b, and data.c....

  }
}

and here is my JS

const ethers = require('ethers');

const pk = '0x...';
const provider = 'http://localhost:8545';
const myContractAddress = '0x...';
const abi = require('./build/MyContract.abi.json');

const wallet = new ethers.Wallet(pk, new ethers.providers.JsonRpcProvider(provider));
const myContract = new ethers.Contract(myContractAddress, abi, wallet);

(async function() {
  const a = '0x...';
  const b = '123123123123132123123';
  const c = true;

  // TODO: How do I encode the struct?
  const myStructData = '???';

  const tx = await myContract.myFunction(
    myStructData,
    { gasLimit: ethers.utils.parseUnits('1000000', 'wei') }
  );
})().catch(console.error);

[ajb413]

This worked for me:

const a = '0x...';
const b = '123123123123132123123';
const c = true;

const myStructData = ethers.utils.AbiCoder.prototype.encode(
  ['address', 'uint', 'bool'],
  [a, b, c]
);

const tx = await myContract.myFunction(
  myStructData,
  { gasLimit: ethers.utils.parseUnits('1000000', 'wei') }
);

[garyng2000]

@ajb413 @ricmoo thanks for the info, learn more about ethers.js(the encode() helper call is very useful) 😃