feat(error-handling): try querying without multicall in case of failure

BREAKING CHANGE: No longer exposing a Multicall.new async function as Multicalls are all deployed at
the same address

README.md

@@ -32,11 +32,7 @@ import { ethers } from "ethers";
 import { EthersMulticall } from "@morpho-labs/ethers-multicall";
 
 const provider = new ethers.providers.JsonRpcBatchProvider("...");
-// pass the chainId as option (second parameter, defaults to 1 = mainnet)
-const multicall = new EthersMulticall(provider, { chainId: 1 });
-
-// if the chainId is unknown, defaults to the provider's network chainId
-const multicall = await EthersMulticall.new(provider)
+const multicall = new EthersMulticall(provider);
 
 const uni = multicall.wrap(
   new ethers.Contract("0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984", UniswapAbi)

contracts/Multicall3.sol

@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.12;
+
+/// @title Multicall3
+/// @notice Aggregate results from multiple function calls
+/// @dev Multicall & Multicall2 backwards-compatible
+/// @dev Aggregate methods are marked `payable` to save 24 gas per call
+/// @author Michael Elliot <mike@makerdao.com>
+/// @author Joshua Levine <joshua@makerdao.com>
+/// @author Nick Johnson <arachnid@notdot.net>
+/// @author Andreas Bigger <andreas@nascent.xyz>
+/// @author Matt Solomon <matt@mattsolomon.dev>
+contract Multicall3 {
+    struct Call {
+        address target;
+        bytes callData;
+    }
+
+    struct Call3 {
+        address target;
+        bool allowFailure;
+        bytes callData;
+    }
+
+    struct Call3Value {
+        address target;
+        bool allowFailure;
+        uint256 value;
+        bytes callData;
+    }
+
+    struct Result {
+        bool success;
+        bytes returnData;
+    }
+
+    /// @notice Backwards-compatible call aggregation with Multicall
+    /// @param calls An array of Call structs
+    /// @return blockNumber The block number where the calls were executed
+    /// @return returnData An array of bytes containing the responses
+    function aggregate(Call[] calldata calls) public payable returns (uint256 blockNumber, bytes[] memory returnData) {
+        blockNumber = block.number;
+        uint256 length = calls.length;
+        returnData = new bytes[](length);
+        Call calldata call;
+        for (uint256 i = 0; i < length;) {
+            bool success;
+            call = calls[i];
+            (success, returnData[i]) = call.target.call(call.callData);
+            require(success, "Multicall3: call failed");
+            unchecked { ++i; }
+        }
+    }
+
+    /// @notice Backwards-compatible with Multicall2
+    /// @notice Aggregate calls without requiring success
+    /// @param requireSuccess If true, require all calls to succeed
+    /// @param calls An array of Call structs
+    /// @return returnData An array of Result structs
+    function tryAggregate(bool requireSuccess, Call[] calldata calls) public payable returns (Result[] memory returnData) {
+        uint256 length = calls.length;
+        returnData = new Result[](length);
+        Call calldata call;
+        for (uint256 i = 0; i < length;) {
+            Result memory result = returnData[i];
+            call = calls[i];
+            (result.success, result.returnData) = call.target.call(call.callData);
+            if (requireSuccess) require(result.success, "Multicall3: call failed");
+            unchecked { ++i; }
+        }
+    }
+
+    /// @notice Backwards-compatible with Multicall2
+    /// @notice Aggregate calls and allow failures using tryAggregate
+    /// @param calls An array of Call structs
+    /// @return blockNumber The block number where the calls were executed
+    /// @return blockHash The hash of the block where the calls were executed
+    /// @return returnData An array of Result structs
+    function tryBlockAndAggregate(bool requireSuccess, Call[] calldata calls) public payable returns (uint256 blockNumber, bytes32 blockHash, Result[] memory returnData) {
+        blockNumber = block.number;
+        blockHash = blockhash(block.number);
+        returnData = tryAggregate(requireSuccess, calls);
+    }
+
+    /// @notice Backwards-compatible with Multicall2
+    /// @notice Aggregate calls and allow failures using tryAggregate
+    /// @param calls An array of Call structs
+    /// @return blockNumber The block number where the calls were executed
+    /// @return blockHash The hash of the block where the calls were executed
+    /// @return returnData An array of Result structs
+    function blockAndAggregate(Call[] calldata calls) public payable returns (uint256 blockNumber, bytes32 blockHash, Result[] memory returnData) {
+        (blockNumber, blockHash, returnData) = tryBlockAndAggregate(true, calls);
+    }
+
+    /// @notice Aggregate calls, ensuring each returns success if required
+    /// @param calls An array of Call3 structs
+    /// @return returnData An array of Result structs
+    function aggregate3(Call3[] calldata calls) public payable returns (Result[] memory returnData) {
+        uint256 length = calls.length;
+        returnData = new Result[](length);
+        Call3 calldata calli;
+        for (uint256 i = 0; i < length;) {
+            Result memory result = returnData[i];
+            calli = calls[i];
+            (result.success, result.returnData) = calli.target.call(calli.callData);
+            assembly {
+                // Revert if the call fails and failure is not allowed
+                // `allowFailure := calldataload(add(calli, 0x20))` and `success := mload(result)`
+                if iszero(or(calldataload(add(calli, 0x20)), mload(result))) {
+                    // set "Error(string)" signature: bytes32(bytes4(keccak256("Error(string)")))
+                    mstore(0x00, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                    // set data offset
+                    mstore(0x04, 0x0000000000000000000000000000000000000000000000000000000000000020)
+                    // set length of revert string
+                    mstore(0x24, 0x0000000000000000000000000000000000000000000000000000000000000017)
+                    // set revert string: bytes32(abi.encodePacked("Multicall3: call failed"))
+                    mstore(0x44, 0x4d756c746963616c6c333a2063616c6c206661696c6564000000000000000000)
+                    revert(0x00, 0x64)
+                }
+            }
+            unchecked { ++i; }
+        }
+    }
+
+    /// @notice Aggregate calls with a msg value
+    /// @notice Reverts if msg.value is less than the sum of the call values
+    /// @param calls An array of Call3Value structs
+    /// @return returnData An array of Result structs
+    function aggregate3Value(Call3Value[] calldata calls) public payable returns (Result[] memory returnData) {
+        uint256 valAccumulator;
+        uint256 length = calls.length;
+        returnData = new Result[](length);
+        Call3Value calldata calli;
+        for (uint256 i = 0; i < length;) {
+            Result memory result = returnData[i];
+            calli = calls[i];
+            uint256 val = calli.value;
+            // Humanity will be a Type V Kardashev Civilization before this overflows - andreas
+            // ~ 10^25 Wei in existence << ~ 10^76 size uint fits in a uint256
+            unchecked { valAccumulator += val; }
+            (result.success, result.returnData) = calli.target.call{value: val}(calli.callData);
+            assembly {
+                // Revert if the call fails and failure is not allowed
+                // `allowFailure := calldataload(add(calli, 0x20))` and `success := mload(result)`
+                if iszero(or(calldataload(add(calli, 0x20)), mload(result))) {
+                    // set "Error(string)" signature: bytes32(bytes4(keccak256("Error(string)")))
+                    mstore(0x00, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                    // set data offset
+                    mstore(0x04, 0x0000000000000000000000000000000000000000000000000000000000000020)
+                    // set length of revert string
+                    mstore(0x24, 0x0000000000000000000000000000000000000000000000000000000000000017)
+                    // set revert string: bytes32(abi.encodePacked("Multicall3: call failed"))
+                    mstore(0x44, 0x4d756c746963616c6c333a2063616c6c206661696c6564000000000000000000)
+                    revert(0x00, 0x84)
+                }
+            }
+            unchecked { ++i; }
+        }
+        // Finally, make sure the msg.value = SUM(call[0...i].value)
+        require(msg.value == valAccumulator, "Multicall3: value mismatch");
+    }
+
+    /// @notice Returns the block hash for the given block number
+    /// @param blockNumber The block number
+    function getBlockHash(uint256 blockNumber) public view returns (bytes32 blockHash) {
+        blockHash = blockhash(blockNumber);
+    }
+
+    /// @notice Returns the block number
+    function getBlockNumber() public view returns (uint256 blockNumber) {
+        blockNumber = block.number;
+    }
+
+    /// @notice Returns the block coinbase
+    function getCurrentBlockCoinbase() public view returns (address coinbase) {
+        coinbase = block.coinbase;
+    }
+
+    /// @notice Returns the block difficulty
+    function getCurrentBlockDifficulty() public view returns (uint256 difficulty) {
+        difficulty = block.difficulty;
+    }
+
+    /// @notice Returns the block gas limit
+    function getCurrentBlockGasLimit() public view returns (uint256 gaslimit) {
+        gaslimit = block.gaslimit;
+    }
+
+    /// @notice Returns the block timestamp
+    function getCurrentBlockTimestamp() public view returns (uint256 timestamp) {
+        timestamp = block.timestamp;
+    }
+
+    /// @notice Returns the (ETH) balance of a given address
+    function getEthBalance(address addr) public view returns (uint256 balance) {
+        balance = addr.balance;
+    }
+
+    /// @notice Returns the block hash of the last block
+    function getLastBlockHash() public view returns (bytes32 blockHash) {
+        unchecked {
+            blockHash = blockhash(block.number - 1);
+        }
+    }
+
+    /// @notice Gets the base fee of the given block
+    /// @notice Can revert if the BASEFEE opcode is not implemented by the given chain
+    function getBasefee() public view returns (uint256 basefee) {
+        basefee = block.basefee;
+    }
+
+    /// @notice Returns the chain id
+    function getChainId() public view returns (uint256 chainid) {
+        chainid = block.chainid;
+    }
+}