I have contract A and contract B with the following structures:

contract A {
  int x;
  function setX(){
       x = _x;

contract B {
   A[] contractInstances;
   function createContractInstance() {
       contractInstances.push(new A());


How can I access the method setX() of the created instance, when I am doing the testing with truffle? P.S. when I try to access them directly from the array, it is not working, cause the js platform sees the contract as string addresses.

1 Answer 1


You have to inspect contract B to discover the instances.

By extension, you need something to inspect. Consider:

contract B {
   address[] public contractInstances;
   function createContractInstance() public returns(A newA) {
       A newA = new A();

Once you have that, then

const A = artifacts.require(A);
const B = artifacts.require(B); // separate .sol file

let aInstance = await b.contractInstances(0); // first one
let a = await A.at(aInstance);

Hope it helps.

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