Using Mesc in foundry tests to avoid hardcoding urls.

Test.t.sol

// See Mesc Reference for setup: https://github.com/paradigmxyz/mesc/tree/main/cli#reference

contract TestSetup is Test {

    function fetchRpcUrlFromMesc(string memory networkName) internal returns (string memory url) {
        string[] memory inputs = new string[](3);
        inputs[0] = "mesc";
        inputs[1] = "url";
        inputs[2] = networkName;

        bytes memory res = vm.ffi(inputs);
        url = string(res);
    }

    function setUp() public {
        string memory network = "avax-c-chain";
        uint256 cchainForkId = vm.createSelectFork(fetchRpcUrlFromMesc(network), 41022344);
        network = "eth-mainnet";
        uint256 mainnetForkId = vm.createSelectFork(fetchRpcUrlFromMesc(network), 19120056);
        // Do something
     }
  }