GreeterFactory.deploy(...) for tests

[SvenMeyer]

Why not also use the factory for the tests as it gives typed deployment parameter instead of a any[] ?

        const GreeterFactory: Greeter__factory = await ethers.getContractFactory("Greeter");
        this.greeter = await GreeterFactory.deploy(deploymentParameter.greeting, deploymentParameter.aNumber);
        await this.greeter.deployed();

[PaulRBerg]

Because if we do that, we lose compatibility with the Waffle features like snapshots and fixtures (and I think mock contracts too).

https://github.com/paulrberg/solidity-template/blob/caed14d1debac5392ee371d0d74ef8b06868b57e/test/Greeter.ts#L9

[supafreq]

What Paul said is correct, but if you still want to type your deploy args, you can pull them out of the *__factory type via Parameters<*__factory['deploy']> (although that will include the optional overrides arg as well).

I've made a utility type that makes this more semantically clear and also removes the last overrides arg:

import { ContractFactory } from "ethers";

type OmitOverrides<T extends any[]> = Required<T> extends [ ...infer ContractArgs, any ] ? ContractArgs : any[];
export type DeployArgs<T extends ContractFactory> = OmitOverrides<Parameters<T['deploy']>>

and you would use it like so:

const artifact: Artifact = await artifacts.readArtifact('MyContract');
const deployArgs: DeployArgs<MyContract__factory> = [
  'some arg',
  'another arg',
]
const myContract = await deployContract(deployer, artifact, deployArgs) as MyContract

[SvenMeyer]

@supafreq thanks., that looks like a good approach (although it adds quite some complexity).

Maybe I just got away with my approach as I am not using "the Waffle features like snapshots and fixtures"?
(... but I like that approach)

import { Whitelist, Whitelist__factory } from "../typechain";

    const whitelistFactory = new Whitelist__factory(this.signers.admin);
    this.whitelist = <Whitelist>await whitelistFactory.deploy(false);
    await this.whitelist.deployed();

... and I actually had to change the deployment (see below) of one testscript (as a quick fix) to the method above because I got a strange error when I used hardhat-coverage

import { Artifact } from "hardhat/types";
const { deployContract } = hre.waffle;

    const whitelistArtifact: Artifact = await hre.artifacts.readArtifact("Whitelist");
    this.whitelist = <Whitelist>await deployContract(this.signers.admin, whitelistArtifact, [false]);

  1) 1_Whitelist.ts =================================================================

       "before all" hook for "set hasWhitelisting to true":
     InvalidInputError: sender doesn't have enough funds to send tx. The upfront cost is: 8796093022200000000000 and the sender's account only has: 2000000000000000000
      at TxPool._validateTransaction (node_modules/hardhat/src/internal/hardhat-network/provider/TxPool.ts:426:13)
      at processTicksAndRejections (internal/process/task_queues.js:97:5)
      at runNextTicks (internal/process/task_queues.js:66:3)
      at listOnTimeout (internal/timers.js:523:9)
      at processTimers (internal/timers.js:497:7)
      at TxPool.addTransaction (node_modules/hardhat/src/internal/hardhat-network/provider/TxPool.ts:102:5)
      at HardhatNode._addPendingTransaction (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:1103:5)
      at HardhatNode._mineTransaction (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:1111:5)
      at EthModule._sendTransactionAndReturnHash (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:1379:18)
      at HardhatNetworkProvider.request (node_modules/hardhat/src/internal/hardhat-network/provider/provider.ts:105:18)