How do I test my contract's constructor?

[colinsteidtmann]

I want to test that state variables are changed after creating a new contract with constructor arguments and setting state variables inside the constructor. I want to do something like openzeppelin's ERC20Mock.new(args..). (https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/test/token/ERC20/ERC20.test.js#L23) inside of a test file. However, deployments.fixture doesn't accept deployment arguments I can pass in. What should I do?

[dcamps-hacken]

Hi!

I don't know why you want to use that specific method... I would suggest you do it like this:

• add chai's assert into your test file: const { assert } = require("chai")

• add a constructor describe and a getter function in your contract to get the variables you want to check --> get the variables --> assert the variables are equal to a certain value: describe("constructor", async function(){ it("sets the state variables correctly, async function() { const yourStateVariable = await contractName.getterFunctionWithStateVarName();
  assert.equal(yourStateVariable, whatYouWantItToBe) }) })

[wighawag]

you can create a specific fixture that deploy a specifically configured contract instance.

the deploy fixture are meant to be used to test the deployment itself, so you would not want to configure it

[Sceat]

Also stated in https://github.com/wighawag/hardhat-deploy/issues/289, it would be really useful to be able to pass constructor arguments when loading fixtures, sometime we may need to test the contract with specific arguments.

await deployments.fixture()
await deployments.fixture({ 'myContract': [...args] })

Imagine you have a addresses Leaderboard contract and to test it you need real signers as players. It would be preferable to deploy it with a length of 2 for the tests so that you need 2 signers, and with a length of 100 in production.

for now we have to write a deploy script for each testing case when it comes to arguments

[wighawag]

@Sceat for the case you mention you could read the number of signers from a different file for test network, You can also add tags to network so you can differentiate between test network and real network programmatically.