Foundry Book

accesses

Signature

function accesses(
  address
)
external
returns (
  bytes32[] memory reads,
  bytes32[] memory writes
);

Description

Gets all storage slots that have been read (reads) or written to (writes) on an address.

Note that record must be called first.

ℹ️ Note

Every write also counts as an additional read.

Examples

/// contract NumsContract {
///     uint256 public num1 = 100; // slot 0
///     uint256 public num2 = 200; // slot 1
/// }

vm.record();
numsContract.num2();
(bytes32[] memory reads, bytes32[] memory writes) = vm.accesses(
  address(numsContract)
);
emit log_uint(uint256(reads[0])); // 1