createFork for same block number multiple times adds an extra / for every call

[maa105]

Component

Forge

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

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (71d8ea5 2024-01-09T14:41:14.837767655Z)

What command(s) is the bug in?

createFork/createSelectFork

Operating System

Linux

Describe the bug

each time you use a createFork for a specific block number it adds a / to the rpcUrl. try:

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.21;

import {console, Test} from "forge-std/Test.sol";

import {Vm} from "forge-std/Vm.sol";

contract MyTest is Test {
    function testStart() public {
        vm.createFork('ws://valid-rpc-url:1000', 18983785);
        vm.createFork('ws://valid-rpc-url:1000', 18983785);
        vm.createFork('ws://valid-rpc-url:1000', 18983785); // <-- it will fail here
    }
}

Error:

    ├─ [0] VM::createFork("ws://valid-rpc-url:1000", 18983785 [18.98e6])
    │   └─ ← Could not instantiate forked environment with fork url: ws://valid-rpc-url:1000//
    └─ ← Could not instantiate forked environment with fork url: ws://valid-rpc-url:1000//

notice the error the fork url adds 2 /

we tried

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.21;

import {console, Test} from "forge-std/Test.sol";

import {Vm} from "forge-std/Vm.sol";

contract MyTest is Test {
    function testStart() public {
        vm.createFork('ws://valid-rpc-url:1000/', 18983785);
        vm.createFork('ws://valid-rpc-url:1000/', 18983785); // <-- it will fail here
        vm.createFork('ws://valid-rpc-url:1000/', 18983785);
    }
}

Notice here we added a / here explicitly. it failed one statement before with the same error with two /

even if we add different block# for createFork it will break only on the third of the same block number.

[maa105]

notice valid-rpc-url:1000 is dummy replacement for our real node

[mattsse]

the added slash was a previous hotfix

properly fixed with #6765

[maa105]

Thx for the fix. We noted also that forking using transaction hash has the same issue i.e. creacteFork(rpcUrl, txHash); 3 times on the same rpcUrl and txHash will cause the same issue. Not sure if this helps

[maa105]

you are awesome guys! tested it with block number and transaction hash both work as expected thanks!