fix(anvil): set storage.best_number correctly

[yash-atreya]

Motivation

Closes #9053 + Closes #8493

This arises when --fork-url and --load-state are used together.

Solution

• Introduce account_at in ForkedStorage which stores the state of accounts at specific block numbers.
• Populate account_at using the provided state file.

Solution is a lot simpler.

• We are correctly loading the data to the db:

  foundry/crates/anvil/src/eth/backend/mem/mod.rs

  Line 925 in 4012ade

  if !self.db.write().await.load_state(state.clone())? {

• However, the storage.best_number i.e head of the chain is not correctly set when --load-state is used with --fork-url. We continue to set storage.best_number = state.block.number which is incorrect as the best_number should be fork_block_number.

• This issue is observed when fork_block_number > state.block_number. In this case while all state data has been correctly loaded to the db, we fetch via the provider due to this check.

  foundry/crates/anvil/src/eth/api.rs

  Line 683 in 4012ade

  if fork.predates_fork(number) {

• Setting storage.best_number = fork_block_number fixes this

• Test

[grandizzy]

@yash-atreya I added a test here, basically dumping state locally from gh issue recreate and reloading / make sure balance properly retrieved, feel free to include in PR if OK

yash/load-forked-state...grandizzy:test-for-9215

[yash-atreya]

@yash-atreya I added a test here, basically dumping state locally from gh issue recreate and reloading / make sure balance properly retrieved, feel free to include in PR if OK

yash/load-forked-state...grandizzy:test-for-9215

@grandizzy thanks for this.

I've added a more comprehensive test. ptal.

[grandizzy]

@yash-atreya I suspect this is supposed to close #8493 too? If so, could you please update description to include it? thank you

[grandizzy]

lgtm!