feat: config helper contract

.env

@@ -0,0 +1,7 @@
+# ETHEREUM MAINNET
+MAINNET_RPC="https://eth.llamarpc.com"
+WETH_MAINNET="0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2"
+
+# OPTIMISM
+OPTIMISM_RPC="https://mainnet.optimism.io"
+WETH_OPTIMISM="0x4200000000000000000000000000000000000006"

src/Base.sol

@@ -1,29 +1,37 @@
 // SPDX-License-Identifier: MIT
 pragma solidity >=0.6.2 <0.9.0;
 
+import {console} from "./console.sol";
 import {StdStorage} from "./StdStorage.sol";
+import {StdConfig} from "./StdConfig.sol";
 import {Vm, VmSafe} from "./Vm.sol";
 
 abstract contract CommonBase {
     /// @dev Cheat code address.
     /// Calculated as `address(uint160(uint256(keccak256("hevm cheat code"))))`.
     address internal constant VM_ADDRESS = 0x7109709ECfa91a80626fF3989D68f67F5b1DD12D;
+
     /// @dev console.sol and console2.sol work by executing a staticcall to this address.
     /// Calculated as `address(uint160(uint88(bytes11("console.log"))))`.
     address internal constant CONSOLE = 0x000000000000000000636F6e736F6c652e6c6f67;
+
     /// @dev Used when deploying with create2.
     /// Taken from https://github.com/Arachnid/deterministic-deployment-proxy.
     address internal constant CREATE2_FACTORY = 0x4e59b44847b379578588920cA78FbF26c0B4956C;
+
     /// @dev The default address for tx.origin and msg.sender.
     /// Calculated as `address(uint160(uint256(keccak256("foundry default caller"))))`.
     address internal constant DEFAULT_SENDER = 0x1804c8AB1F12E6bbf3894d4083f33e07309d1f38;
+
     /// @dev The address of the first contract `CREATE`d by a running test contract.
     /// When running tests, each test contract is `CREATE`d by `DEFAULT_SENDER` with nonce 1.
     /// Calculated as `VM.computeCreateAddress(VM.computeCreateAddress(DEFAULT_SENDER, 1), 1)`.
     address internal constant DEFAULT_TEST_CONTRACT = 0x5615dEB798BB3E4dFa0139dFa1b3D433Cc23b72f;
+
     /// @dev Deterministic deployment address of the Multicall3 contract.
     /// Taken from https://www.multicall3.com.
     address internal constant MULTICALL3_ADDRESS = 0xcA11bde05977b3631167028862bE2a173976CA11;
+
     /// @dev The order of the secp256k1 curve.
     uint256 internal constant SECP256K1_ORDER =
         115792089237316195423570985008687907852837564279074904382605163141518161494337;
@@ -35,8 +43,57 @@ abstract contract CommonBase {
     StdStorage internal stdstore;
 }
 
-abstract contract TestBase is CommonBase {}
 
-abstract contract ScriptBase is CommonBase {
+/// @notice Boilerplate to streamline the setup of multi-chain testing environments.
+abstract contract CommonConfig is CommonBase {
+
+    // -- STORAGE (CONFIG + CHAINS + FORKS) ------------------------------------
+
+    StdConfig internal config;
+    uint256[] internal chainIds;
+    mapping(uint256 chainId => uint256 forkId) internal forkOf;
+
+    // -- HELPER FUNCTIONS -----------------------------------------------------
+
+    /// @notice  Loads configuration from a file.
+    ///
+    /// @dev     This function instantiates a `Config` contract, caching all its config variables.
+    ///
+    /// @param   filePath: the path to the TOML configuration file.
+    function _loadConfig(string memory filePath) internal {
+        console.log("----------");
+        console.log(string.concat("Loading config from '", filePath, "'"));
+        config = new StdConfig(filePath);
+        vm.makePersistent(address(config));
+        console.log("Config successfully loaded");
+        console.log("----------");
+    }
+
+    /// @notice  Loads configuration from a file and creates forks for each specified chain.
+    ///
+    /// @dev     This function instantiates a `Config` contract, caching all its config variables,
+    ///          reads the configured chain ids, and iterates through them to create a fork for each one.
+    ///          It also creates a map `forkOf[chainId] -> forkId` to easily switch between forks.
+    ///
+    /// @param   filePath: the path to the TOML configuration file.
+    function _loadConfigAndForks(string memory filePath) internal {
+        _loadConfig(filePath);
+
+        console.log("Setting up forks for the configured chains...");
+        uint256[] memory chains = config.getChainIds();
+        for (uint i = 0; i < chains.length; i++) {
+            uint256 chainId = chains[i];
+            uint256 forkId = vm.createFork(config.getRpcUrl(chainId));
+            forkOf[chainId] = forkId;
+            chainIds.push(chainId);
+        }
+        console.log("Forks successfully created");
+        console.log("----------");
+    }
+}
+
+abstract contract TestBase is CommonConfig {}
+
+abstract contract ScriptBase is CommonConfig {
     VmSafe internal constant vmSafe = VmSafe(VM_ADDRESS);
 }