Truffle Contract Factory Testing (Javascript)

Question

I have a hub contract (1) that uses a contract factory (2) to create a contract (3). I am writing some tests in JavaScript to ensure that contract 3 is created correctly. I can tell events are being emitted correctly, but when I want to check the functions of contract 3 (#tryingtobethorough), it looks like Truffle does not recognize the created contract 3 address as a contract (i.e. TypeError: contract3Address.functionName is not a function). Does Truffle Javascript testing only recognize addresses as contracts if deployed through Truffle migrations? Is there a work around for this in Javascript? Perhaps it is a better test case for Solidity testing?

Below is some simplified versions of what I am working with:

Contract 1: Hub

import "./Contract2Interface.sol"; 

contract Contract1 {
    Contract2Interface I; 
    function Contract1(address Contract2Address){
        I = Contract2Interface(Contract2Address); 
    }
    function creation() returns (address newcontract3) {
        address theCreatedContract3 = I.createNewContract3();
        return newcontract3; 
    }
}

Contract 2: Contract Factory

import "./Contract3.sol";
import "./Contract2Interface.sol";

contract Contract2 is Contract2Interface {
    event ContractCreation(address _newContract);

    function createNewContract3() public returns(address) {

        Contract3 createdContract3 = new Contract3(); 
        ContractCreation(createdContract3);
        return createdContract3; 

    }
}

Contract 3: Contract to be Created

contract Contract3{
    uint256 public num; 
    function storeNum(uint256 newNum) public returns(bool) {
        num = newNum; 
    }
}

JavaScript Test This is simplified, but I think it gives enough of an idea.

beforeEach(async function(){
    contractFactory = await Contract2.new(); 
    contractHub = await Contract1.new(contractFactory.address);
  });

describe("Creating contract 3", async function(){
    it("Should allow us to create contract 3", async function(){
      let result = await contract1.createNewContract3({from: owner});
      //Event data 
      let log = resultTwo.logs[0];
      let contract3Address = log.args._newContract;
      console.log(contract3Address) //I can see this is a valid contract address & event has been emitted properly.
      let newnum = await contract3Address.storeNum(7);
      // At this point I get an error that "storeNum" is not a function of contract3Address from Truffle testing
    })
  })

Answer 1

A couple of issues

In the function creation of Contract1 you are returning newcontract3 without it being assigned a value, since it is an addres the returned value will be default address(0x0). You probably want to assign the result of createNewContract3().

function creation() returns (address newcontract3) {
    newcontract3 = I.createNewContract3();
    return newcontract3; 
}

In your test you assign to contract3Address the parameter of the event which is of type string. In truffle when you want to interact with a contract at a given address you need to get an instance pointing to that address, ie const myContract = await MyContract.at("address");.

describe("Creating contract 3", async function(){
    it("Should allow us to create contract 3", async function(){
      let result = await contract1.createNewContract3({from: owner});
      //Event data 
      let log = resultTwo.logs[0];
      let contract3Address = log.args._newContract;

      // Get instance pointing to address obtained from event
      const contract3 = await Contract3.at(contract3Address);

      let newnum = await contract3.storeNum(7);
      // At this point I get an error that "storeNum" is not a function of contract3Address from Truffle testing
    })
  })