feat: Utilize generic to better support Typechain types

[phated]

I'm guessing this will need to be iterated a bit, but I wanted to open this for discussion.

Essentially, what we are hoping to achieve is a better devex than using as Something to cast a contract to a Typechain contract type, which already extends ether's Contract.

The result would look something like this:

const UtilsFactory = await hre.ethers.getContractFactory('Utils');

// Notice the `: UtilsContract ` here, which casts the Contract return to the Typechain type
const utils: UtilsContract = await UtilsFactory.deploy();

await utils.deployed();

// We could then use custom RPC methods on UtilsContract and have it fully typechecked here.

[ricmoo]

I think TypeChain has already added this, by extending the BaseContract object, no?

The abstraction has been added to ethers, to make it easier for this sort of abstraction, check out #1384 and let me know if that helps.

[phated]

@ricmoo Thanks for pointing me to those changes. I tried upgrading everything in my lockfile and I think there's still a problem because when I get the following typechecking error:

Type 'Contract' is missing the following properties from type 'UtilsContract': testFn, "testFn(bytes32[])", changeAdmin, "changeAdmin(address)", and 18 more.ts(2740)

cc @krzkaczor

[krzkaczor]

I reopened that issue as I run into some problems (see #1384 (comment)).

@phated regarding this issue. This is not really related to ethers but to Hardhat and TypeChain integration. You will love this: dethcrypto/TypeChain#370

Btw. thanks for CCing me in this thread ;)

[phated]

I think this is solved by typechain v5