Testing contracts that have construction parameters

Question

How do I test a contract with that has construction parameters? For example what if I had slightly modified the metacoin example contract to include an initial_balance

contract MetaCoin {
  mapping (address => uint) balances;

  function MetaCoin(uint initial_balance) {
    balances[tx.origin] = initial_balance;
  }
  ...

How do I modify the example TestMetacoin.sol

import "truffle/Assert.sol";
import "truffle/DeployedAddresses.sol";
import "../contracts/MetaCoin.sol";

contract TestMetacoin {
  function testInitialBalanceUsingDeployedContract() {
    MetaCoin meta = MetaCoin(DeployedAddresses.MetaCoin());

    uint expected = 10000;

    Assert.equal(meta.getBalance(tx.origin), expected, "Owner should have 10000 MetaCoin initially");
  }
  ...

AFAIK the truffle test runner deploys the contracts and the Metacoin(DeployedAddresses.Metacoin()) gets the deployed contract to test. But I don't see any way to pass in the initial_balance to test it.

Answer 1

There are two solutions.

First solution: change your migrations file and add second parameter here:

deployer.deploy(Contract, initial_balance)

---

Second solution: just deploy new contract inside your test:

contract TestMetacoin {
  function testInitialBalanceUsingDeployedContract() {
    MetaCoin meta = new MetaCoin(10000);

    uint expected = 10000;

    Assert.equal(meta.getBalance(tx.origin), expected, "Owner should have 10000 MetaCoin initially");
}