Files
openzeppelin-contracts/test/utils/Blockhash.t.sol
2025-04-29 16:05:27 -06:00

101 lines
3.8 KiB
Solidity

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
import {Test} from "forge-std/Test.sol";
import {Blockhash} from "../../contracts/utils/Blockhash.sol";
contract BlockhashTest is Test {
uint256 internal startingBlock;
address internal constant SYSTEM_ADDRESS = 0xffffFFFfFFffffffffffffffFfFFFfffFFFfFFfE;
// See https://eips.ethereum.org/EIPS/eip-2935#bytecode
// Generated using https://www.evm.codes/playground
bytes private constant HISTORY_STORAGE_BYTECODE =
hex"3373fffffffffffffffffffffffffffffffffffffffe14604657602036036042575f35600143038111604257611fff81430311604257611fff9006545f5260205ff35b5f5ffd5b5f35611fff60014303065500";
function setUp() public {
vm.roll(block.number + 100);
startingBlock = block.number;
vm.etch(Blockhash.HISTORY_STORAGE_ADDRESS, HISTORY_STORAGE_BYTECODE);
}
function testFuzzRecentBlocks(uint8 offset, uint64 currentBlock, bytes32 expectedHash) public {
// Recent blocks (1-256 blocks old)
uint256 boundedOffset = uint256(offset) + 1;
vm.assume(currentBlock > boundedOffset);
vm.roll(currentBlock);
uint256 targetBlock = currentBlock - boundedOffset;
vm.setBlockhash(targetBlock, expectedHash);
bytes32 result = Blockhash.blockHash(targetBlock);
assertEq(result, blockhash(targetBlock));
assertEq(result, expectedHash);
}
function testFuzzHistoryBlocks(uint16 offset, uint256 currentBlock, bytes32 expectedHash) public {
// History blocks (257-8191 blocks old)
offset = uint16(bound(offset, 257, 8191));
vm.assume(currentBlock > offset);
vm.roll(currentBlock);
uint256 targetBlock = currentBlock - offset;
_setHistoryBlockhash(targetBlock, expectedHash);
bytes32 result = Blockhash.blockHash(targetBlock);
(bool success, bytes memory returndata) = Blockhash.HISTORY_STORAGE_ADDRESS.staticcall(
abi.encodePacked(bytes32(targetBlock))
);
assertTrue(success);
assertEq(result, abi.decode(returndata, (bytes32)));
assertEq(result, expectedHash);
}
function testFuzzVeryOldBlocks(uint256 offset, uint256 currentBlock) public {
// Very old blocks (>8191 blocks old)
offset = bound(offset, 8192, type(uint256).max);
vm.assume(currentBlock > offset);
vm.roll(currentBlock);
uint256 targetBlock = currentBlock - offset;
bytes32 result = Blockhash.blockHash(targetBlock);
assertEq(result, bytes32(0));
}
function testFuzzFutureBlocks(uint256 offset, uint256 currentBlock) public {
// Future blocks
offset = bound(offset, 1, type(uint256).max);
vm.roll(currentBlock);
unchecked {
uint256 targetBlock = currentBlock + offset;
bytes32 result = Blockhash.blockHash(targetBlock);
assertEq(result, blockhash(targetBlock));
}
}
function testUnsupportedChainsReturnZeroWhenOutOfRange() public {
vm.etch(Blockhash.HISTORY_STORAGE_ADDRESS, hex"");
vm.roll(block.number + 1000);
assertEq(Blockhash.blockHash(block.number - 1000), bytes32(0));
}
function _setHistoryBlockhash(bytes32 blockHash) internal {
_setHistoryBlockhash(block.number, blockHash);
}
function _setHistoryBlockhash(uint256 blockNumber, bytes32 blockHash) internal {
// Subtracting 1 due to bug encountered during coverage
uint256 currentBlock = block.number - 1;
vm.assume(blockNumber < type(uint256).max);
vm.roll(blockNumber + 1); // roll to the next block so the storage contract sets the parent's blockhash
vm.prank(SYSTEM_ADDRESS);
(bool success, ) = Blockhash.HISTORY_STORAGE_ADDRESS.call(abi.encode(blockHash)); // set parent's blockhash
assertTrue(success);
vm.roll(currentBlock + 1);
}
}