ContractFactory violates Liskov substitution principle

Suppose i have a simple contract

pragma solidity ^0.6.0;

contract MyContract {
    constructor (address a) public {
    }
}

Using typechain i obtain MyContractFactory.

Unfortunately MyContractFactory lacks functionality compared to the ethers ContractFactory.

1. new MyContractFactory(wallet).deploy(…) does not accept overrides as the last argument
2. casting new MyContractFactory(wallet) as ContractFactory and then calling deploy with an incorrect number of arguments we do not get the proper error about argument count from ethers.

Suggested fix (not tested):

class MyContractFactory {
  deploy(a: string, overrides: providers.TransactionRequest): Promise<MyContract>
  deploy(...args: any[]): Promise<MyContract> {
    super.deploy(...args) as Promise<MyContract>
  }
}

[sz-piotr]

@quezak Sure. Here is the relevant code: https://github.com/ethers-io/ethers.js/blob/748f89660ac4bf60175f936da755cf1a0d370f46/src.ts/contract.ts#L798

[krzkaczor]

📦 Released as typechain-target-ethers@1.0.4