Improve typings for contracts

Hey Richard!

I am the maintainer of TypeChain and I would like to forward some ideas that would greatly improve our generated types. I am more than happy to make PRs to fix this - I just want to discuss these ideas first here.

1. TypeChain generated contracts extend packages/contracts/src.ts/index.ts/Contract class. The problem is that this class has index signatures for functions which we can’t override in any way.

Example: readonly functions: { [ name: string ]: ContractFunction };

Despite the fact that we generate exact typings for all contract methods it’s possible to mistype a method name and use a generic ContractFunction. This should result in a type error. I would propose extracting BaseContract interface without any index signatures so both ethers’s Contract and TypeChain generated types can extend that.

Related to: https://github.com/ethereum-ts/TypeChain/issues/276 and https://github.com/ethereum-ts/TypeChain/issues/351

1. We realized that packages/contracts/src.ts/index.ts/Overrides is missing { from?: string | Promise<string> }. I would like to add it.

Related to: https://github.com/ethereum-ts/TypeChain/pull/345

WDYT? As I mentioned already I can prepare PR if you approve these changes.

[ricmoo]

This is now in 5.1.0. Try it out and let me know how it goes. 😃

[krzkaczor]

@ricmoo closing this now. The problem that I described above was caused by ethers version mismatch. Thanks! Ethers & TypeChain work great together now!