Contract & function selector outside of target contracts & selector list is running in invariant/stateful fuzz test

[PatrickAlphaC]

Component

Forge

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

• [X] Foundry
• [X] Foundryup

What version of Foundry are you on?

forge 0.2.0 (dee4181 2023-10-29T00:19:39.178906000Z)

What command(s) is the bug in?

forge test --mt invariant_deltaXFollowsMath --fuzz-seed 1 -vvvvv

Operating System

macOS (Intel)

Describe the bug

I have the following setup for running stateful fuzz/invariant tests.

    function setUp() public {
        // deploy some contracts here...

        // Override the WETH address cuz it's hard-coded in the codebase and I want to mint easily
        deployCodeTo("ERC20Mock.sol:ERC20Mock", address(pool.WETH_TOKEN()));

        // do some parameter setup here...
        handler = new Handler();

        bytes4[] memory selectors = new bytes4[](2);
        selectors[0] = handler.deposit.selector;
        selectors[1] = handler.swapPoolTokenForWethBasedOnOutputWeth.selector;

        targetSelector(FuzzSelector({ addr: address(handler), selectors: selectors }));
        targetContract(address(handler));
    }

The setup clearly states there are 2 selectors to call function on:

• swapPoolTokenForWethBasedOnOutputWeth
• deposit

However, when I run my test, it appears to be adding odd function selectors & contracts. Here is my test:

(I have some ghost variables that I'm checking an invariant on)

    function invariant_deltaXFollowsMath() public {
        assertEq(handler.actualDeltaX(), handler.expectedDeltaX());
    }

And after running:

forge test --mt invariant_deltaXFollowsMath --fuzz-seed 1 -vvvvv

I keep breaking on this:

  [10349] Invariant::invariant_deltaXFollowsMath() 
    ├─ [2351] Handler::actualDeltaX() [staticcall]
    │   └─ ← -49999999999000000407
    ├─ [2308] Handler::expectedDeltaX() [staticcall]
    │   └─ ← -49999999999000000407
    └─ ← ()

  [2854] WETH9::burn(0x6E220FA17Fa68558Dc8884247dcD3d4D915Bba78, 115792089237316195423570985008687907853269984665640564039457584007913129639934 [1.157e77]) 
    └─ ← "ERC20InsufficientBalance(0x6E220FA17Fa68558Dc8884247dcD3d4D915Bba78, 0, 115792089237316195423570985008687907853269984665640564039457584007913129639934 [1.157e77])"

It appears to be adding the WETH9 contract to my target list, and all it's selector.

...so my question is, why?

[PatrickAlphaC]

After some testing, I removed:

// Override the WETH address cuz it's hard-coded in the codebase and I want to mint easily
deployCodeTo("ERC20Mock.sol:ERC20Mock", address(pool.WETH_TOKEN()));

And replaced the hard-coded values with immutable ones, and the error went away. Looks like something fishy happens to target contracts & selectors when you use deployCodeTo to overwrite a contract address.

[grandizzy]

https://github.com/foundry-rs/foundry/pull/7595 fix is available, @mattsse this one can be closed

[yan-man]

Had similar issues here, can confirm that updating to the latest version with foundryup resolved the issues with targetContract and targetSelector. Thanks!