Add jsonrpc call() method (#71)

flashbots · Mar 27, 2024 · 9d65cba · 9d65cba
1 parent f82dfba
commit 9d65cba
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diff --git a/src/protocols/EthJsonRPC.sol b/src/protocols/EthJsonRPC.sol
@@ -4,6 +4,8 @@ pragma solidity ^0.8.13;
 import "../suavelib/Suave.sol";
 import "solady/src/utils/JSONParserLib.sol";
 import "solady/src/utils/LibString.sol";
+import "forge-std/console.sol";
+import "../utils/HexStrings.sol";
 
 /// @notice EthJsonRPC is a library with utilities to interact with an Ethereum JSON-RPC endpoint.
 contract EthJsonRPC {
@@ -30,6 +32,24 @@ contract EthJsonRPC {
         return val;
     }
 
+    /// @notice call a contract function.
+    /// @param to the address of the contract.
+    /// @param data the data of the function.
+    /// @return the result of the function call.
+    function call(address to, bytes memory data) public returns (bytes memory) {
+        bytes memory body = abi.encodePacked(
+            '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"',
+            LibString.toHexStringChecksummed(to),
+            '","data":"',
+            LibString.toHexString(data),
+            '"},"latest"],"id":1}'
+        );
+
+        JSONParserLib.Item memory item = doRequest(string(body));
+        bytes memory result = HexStrings.fromHexString(_stripQuotesAndPrefix(item.value()));
+        return result;
+    }
+
     function doRequest(string memory body) public returns (JSONParserLib.Item memory) {
         Suave.HttpRequest memory request;
         request.method = "POST";
@@ -44,6 +64,15 @@ contract EthJsonRPC {
         return item.at('"result"');
     }
 
+    function _stripQuotesAndPrefix(string memory s) internal pure returns (string memory) {
+        bytes memory strBytes = bytes(s);
+        bytes memory result = new bytes(strBytes.length - 4);
+        for (uint256 i = 3; i < strBytes.length - 1; i++) {
+            result[i - 3] = strBytes[i];
+        }
+        return string(result);
+    }
+
     function trimQuotes(string memory input) private pure returns (string memory) {
         bytes memory inputBytes = bytes(input);
         require(

diff --git a/test/protocols/EthJsonRPC.t.sol b/test/protocols/EthJsonRPC.t.sol
@@ -14,6 +14,15 @@ contract EthJsonRPCTest is Test, SuaveEnabled {
         assertEq(nonce, 0);
     }
 
+    function testEthJsonRPCCall() public {
+        EthJsonRPC ethjsonrpc = getEthJsonRPC();
+
+        bytes memory data = abi.encodeWithSignature("get_deposit_count()");
+        bytes memory result = ethjsonrpc.call(address(0x00000000219ab540356cBB839Cbe05303d7705Fa), data);
+
+        require(result.length > 0, "result is empty");
+    }
+
     function getEthJsonRPC() public returns (EthJsonRPC ethjsonrpc) {
         try vm.envString("JSONRPC_ENDPOINT") returns (string memory endpoint) {
             ethjsonrpc = new EthJsonRPC(endpoint);