VM: Replace Class-Referencing Tx Typing

[holgerd77]

The VM in runTx() is drawing everything from tx in, for all tx types, even if just one specifc tx type is used (the following is from a simple legacy tx run).

What is generally structurally suboptimal and what is somewhat likely the cause here is that we type the tx by this class-referencing Transaction interface (in types.ts in tx):

export interface Transaction {
  [TransactionType.Legacy]: LegacyTransaction
  [TransactionType.FeeMarketEIP1559]: FeeMarketEIP1559Transaction
  [TransactionType.AccessListEIP2930]: AccessListEIP2930Transaction
  [TransactionType.BlobEIP4844]: BlobEIP4844Transaction
  [TransactionType.EOACodeEIP7702]: EOACodeEIP7702Transaction
}

So, e.g. FeeMarketEIP1559Transaction is just the class.

We do have a separate type structure, fully interface based in tx, with e.g. TransactionInterface and sub (?) interfaces EIP1559CompatibleTx.

This structure should - likely ? - be used instead and the Transaction interface removed.

This whole thing likely needs validation, I am not 100% sure. Just to note that this is not optimal yet, eventually this is a solution (or: improvement).

The whole thing might also go together with a further tx refactoring (which - if done - needs to be thought through really thoroughly).

[ScottyPoi]

I worked on this a bit. At first it seemed like it would be fairly straightforward to replace Transaction[T] with TransactionInterface<T>.

Where it gets messy is where we had Transaction[T] as a return type for the transaction factory functions. I think there is some ambiguity in the way our interfaces are built, or the conditionals in the functions aren't explicit enough, because I can't use TransactionInterface<T> as a return type as its currently written without a bunch of as unknown helpers in there.

[ScottyPoi]

I think if we were to upgrade our version of Typescript, we would be able do do some clever things with interfaces that we can't do with our current version.

Currently we can't override attributes when we extend interfaces, but that is a feature of more current versions of typescript. If we can override the type attribute as we extend the TX data and TX interfaces, then functions that use the generic interfaces can infer the correct return type.

[holgerd77]

Yeah, be careful with this task respectively this is definitely not a simple side task, this goes deep into the tx library and likely (guess as you also proofed) touches the current suboptimalities at its core.

So if you want to have further look, maybe don't try to "solve" it, have somethin ready or so, but rather put the effort on finding things out/getting some steps further, by reporting on the problems which arise, so that we can evolve here together.

Respectively this might also be some working towards @jochem-brouwer, who wants to do some broader continued/evolved refactoring, so that he might be able to integrate stuff/get ideas/bring things a bit more together.

[holgerd77]

Also side comment: it is definitely desired that we go to a more up-to-date TypeScript version, so that would definitely be a good task "on its own" (so: without any non-necessary code improvements in the same PR).

So if you want to do that you are very welcome! 🙂 (if you do not, can you please open an issue, so that we keep having this on the plate?)

Maybe it's advisable to not directly go to 5.5 but make one or two in-between steps to not have to deal with too much stuff at once? 🤔 But also do not have a good feeling on how disruptive TypeScript releases really are!

Before we jump on new fancy TypeScript features we should also have a short exchange in the team chat what the effects might be, respectively always a good idea to google a bit, just as a side note.

[holgerd77]

Ok, from a bundling perspective this is not a problem respectively was not the cause, I solved this in #3601, see initial notes for details. I will close here, since generally not sure if worth a rewrite, also since this issue was written from a bundling perspective.

if @jochem-brouwer still wants to change typing along his tx refactor this can for sure still be done, but this will then likely evolve from working with the libraries and not from a top-to-bottom issue.