Hex data being truncated in anvil_dumpState

[NiloCK]

Component

Anvil

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (c2e5297 2024-06-14T00:18:12.274395967Z)

What command(s) is the bug in?

anvil_dumpState

Operating System

Linux

Describe the bug

When running a state dump, the produced output isn't as read-compatible as it could be.

For the attached dump.json, the following geth code fails as described:

var dump state.Dump
err = json.Unmarshal(unzipped, &dump)

if err != nil {
	panic(err)
}
// panic: json: cannot unmarshal hex string of odd length into Go struct field
//        DumpAccount.accounts.storage of type common.Hash

Inspecting the json shows the following. (comments inserted)

...

"0x068e44eb31e111028c41598e4535be7468674d0a": { // line 32, a contract address

...

"0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc": "0x68e44eb31e111028c41598e4535be7468674d0a", // line 172, a reference to that contract
"0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103": "0x9e2803ad9ecc0a848c8a045329524d295f6ee44f",
"0xd30e835d3f35624761057ff5b27d558f97bd5be034621e62240e5c0b784abe68": "0x9965507d1a55bcc2695c58ba16fb37d819b0a4dc"

It seems that the leading zero of the address was truncated, leading to the deserialize failure.

dump.json

[mattsse]

right, we should convert these to B256 because these should mirror how storage is usually formatted

foundry/crates/anvil/src/eth/backend/db.rs

Line 345 in f673066

pub storage: BTreeMap<U256, U256>,

cc @samlaf

[mattsse]

@yash-atreya this should be straight forward, if you find the time

[AxelAramburu]

Hi, it's possible to take this task even if it's already assigned ?

[mattsse]

sure,
I believe @yash-atreya hasn't started yet?

assigning @AxelAramburu

[samlaf]

Curious in general, when would you use U256 (256 bits) vs B256 (32 bytes)?

[mattsse]

the evm internally prefers u256 but technically all those are hashes