Tracing shows wrong values for event parameters

[leonardoalt]

Component

Forge

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

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.1.0 (bea3ddc 2022-02-05T13:11:27.746438742+00:00)

What command(s) is the bug in?

forge test -vvvv

Operating System

Linux

Describe the bug

Write the following test

pragma solidity >=0.8.10;

import "ds-test/test.sol";

contract Test is DSTest {
    event A(uint, uint);

    function setUp() public {}

    function test_event() public {
        uint a = 42;
        uint t = 9723;
        emit A(a, a);
        emit A(a, t);
        emit A(t, a);
        emit A(t, t);
    }
}

Run forge test -vvvv. On my machine I get the output

[PASS] test_event() (gas: 5623)
Traces:

  [5623] Test::test_event()
    ├─ emit A(: 42, : 42)
    ├─ emit A(: 9723, : 9723)
    ├─ emit A(: 42, : 42)
    ├─ emit A(: 9723, : 9723)
    └─ ← ()

[brockelmore]

unfortunately this is upstream in ethabi.

RawLog { topics: [0x83f86eb20c894914ecf65cefc94682009cdb5066a609e8428699fa87b19b5c57], data: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 37, 251, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42] }

parsed: Log { params: [LogParam { name: "", value: Uint(42) }, LogParam { name: "", value: Uint(42) }] }

using just an ethabi::Event, unnamed parameters in events break log parsing.

Naming them fixes ethabi bug:

RawLog { topics: [0x83f86eb20c894914ecf65cefc94682009cdb5066a609e8428699fa87b19b5c57], data: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 37, 251, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42] }

parsed: Log { params: [LogParam { name: "a", value: Uint(9723) }, LogParam { name: "b", value: Uint(42) }] }

edit: there is an open issue upstream: rust-ethereum/ethabi#206

[gakonst]

Closing as Brock's workaround works and this is tracked in ethabi