Add vm.assertContains with overloads (String, etc..)

[johnnyshankman]

Component

Forge

Describe the feature you would like

In the DS Test assertions there should be a assertStringContains(string, string) method for checking strings interpolation.

Additional context

Since we are not deploying these contracts to the network, the gas costs of doing string contains is negligible. It's extremely useful in testing on-chain NFT data etc and straight forward enough to do with two for loops that convert to bytes.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;

contract StringContains {

    function assertStringContains(string memory _base, string memory _value) public pure returns (bool) {
        bytes memory baseBytes = bytes(_base);
        bytes memory valueBytes = bytes(_value);

        if (valueBytes.length == 0) {
            return true;
        }

        if (baseBytes.length < valueBytes.length) {
            return false;
        }

        for (uint i = 0; i <= baseBytes.length - valueBytes.length; i++) {
            bool found = true;
            for (uint j = 0; j < valueBytes.length; j++) {
                if (baseBytes[i + j] != valueBytes[j]) {
                    found = false;
                    break;
                }
            }
            if (found) {
                return true;
            }
        }
        return false;
    }
}

I use this in my tests. It works for every situation I've thrown at it but I have not unit tested this method itself.

[johnnyshankman]

Btw let me know if anything here is unclear. Hopefully pretty straight forward request 🙏 thanks y'all!

Would make a PR myself but I don't have the time this week to dive into the Foundry repo. Hopefully soon.

Been just shimming this thing into any test file that needs it via solidity import.

[johnnyshankman]

@mds1 any updates on this feature request? been quite a while so i just figured I'd bump this.

[mattsse]

I think this would be a nice assert to have.

though we probably want this as native cheatcode impl and not implemented in solidity itself.

forge-std/Test.sol then could simply call vm.assertStringContains?

[leovct]

Hi @zerosnacks, happy to tackle this issue :)