DeployedAddresses + Error: VM Exception while processing transaction: revert - ethereum

Question

I have a contract like following -
File Name: dummycontrat.sol
pragma solidity ^0.4.17;
contract DummyContract {
function fetchRandomNumber() public pure returns(uint) {
uint res = 10;
return res;
}
}
I have the following test file -
FileName: test/TestDummyContract.sol
pragma solidity ^0.4.17;
import "truffle/Assert.sol";
import "truffle/DeployedAddresses.sol";
import "../contracts/dummycontract.sol";
contract TestDummyContract {
function testRandomNumberNew() public {
DummyContract dummyContract = new DummyContract();
uint randomNumber = dummyContract.fetchRandomNumber();
Assert.equal(randomNumber, 10, "Number is not 10");
}
function testRandomNumberDeployed() public {
DummyContract dummyContract = DummyContract(DeployedAddresses.DummyContract());
uint randomNumber = dummyContract.fetchRandomNumber();
Assert.equal(randomNumber, 10, "Number is not 10");
}
}
I run the command -
truffle compile && truffle migrate --reset --network dev && truffle test --network dev test/TestDummyContract.sol
The first test passes while the second gives an error. Logs from the truffle test command is following -
TestDummyContract
✓ testRandomNumberNew (53ms)
1) testRandomNumberDeployed
> No events were emitted
1 passing (894ms)
1 failing
1) TestDummyContract testRandomNumberDeployed:
Error: VM Exception while processing transaction: revert
at Object.InvalidResponse (/usr/local/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/errors.js:38:1)
at /usr/local/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/requestmanager.js:86:1
at /usr/local/lib/node_modules/truffle/build/webpack:/~/truffle-provider/wrapper.js:134:1
at XMLHttpRequest.request.onreadystatechange (/usr/local/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/httpprovider.js:128:1)
at XMLHttpRequestEventTarget.dispatchEvent (/usr/local/lib/node_modules/truffle/build/webpack:/~/xhr2/lib/xhr2.js:64:1)
at XMLHttpRequest._setReadyState (/usr/local/lib/node_modules/truffle/build/webpack:/~/xhr2/lib/xhr2.js:354:1)
at XMLHttpRequest._onHttpResponseEnd (/usr/local/lib/node_modules/truffle/build/webpack:/~/xhr2/lib/xhr2.js:509:1)
at IncomingMessage.<anonymous> (/usr/local/lib/node_modules/truffle/build/webpack:/~/xhr2/lib/xhr2.js:469:1)
at endReadableNT (_stream_readable.js:974:12)
at _combinedTickCallback (internal/process/next_tick.js:80:11)
at process._tickCallback (internal/process/next_tick.js:104:9)
Can anyone explain what's the problem here? I am running Ganache tool on OSX for the network.

Answer 1

DeployedAddresses.DummyContract() is failing because only contracts that are included in the Truffle deployment configurations are made available to DeployedAddresses. From the Truffle documentation:
The addresses of your deployed contracts (i.e., contracts that were deployed as part of your migrations) are available through the truffle/DeployedAddresses.sol library. This is provided by Truffle and is recompiled and relinked before each suite is run to provide your tests with Truffle's a clean room environment. This library provides functions for all of your deployed contracts, in the form of:
DeployedAddresses.<contract name>();
To fix your issue, you need to create the deployment configuration under /migrations (or add to your existing one, if you have it). For example:
2_deploy_contracts.js:
var DummyContract = artifacts.require("dummycontract");
module.exports = function(deployer) {
deployer.deploy(DummyContract);
};
Add that configuration, rerun truffle migrate --reset then your test will work.