feat: vm.blobhashes (foundry-rs#7001)

* feat: `vm.blobhashes`

* chore: rename

* test: add `vm.blobhashes` test

* fix: add missing vm fn

* fix: `cargo cheat`

* fix: specify blobhashes loc

* fix: use solidity 0.8.24 for blobhash test

* chore: reinsert noop line ¯\_(ツ)_/¯

* refactor: move cancun cheats to sep dir

* temp

* temp

* feat(cheatcodes): getBlobhashes

---------

Co-authored-by: Yash Atreya <[email protected]>

crates/cheatcodes/spec/src/vm.rs

@@ -381,6 +381,18 @@ interface Vm {
     #[cheatcode(group = Evm, safety = Unsafe)]
     function prevrandao(uint256 newPrevrandao) external;
 
+    /// Sets the blobhashes in the transaction.
+    /// Not available on EVM versions before Cancun.
+    /// If used on unsupported EVM versions it will revert.
+    #[cheatcode(group = Evm, safety = Unsafe)]
+    function blobhashes(bytes32[] calldata blobhashes) external;
+
+    /// Gets the blockhashes from the current transaction.
+    /// Not available on EVM versions before Cancun.
+    /// If used on unsupported EVM versions it will revert.
+    #[cheatcode(group = Evm, safety = Unsafe)]
+    function getBlobhashes() external view returns (bytes32[] memory blobhashes);
+
     /// Sets `block.height`.
     #[cheatcode(group = Evm, safety = Unsafe)]
     function roll(uint256 newHeight) external;

crates/cheatcodes/src/evm.rs

@@ -303,6 +303,31 @@ impl Cheatcode for prevrandao_1Call {
     }
 }
 
+impl Cheatcode for blobhashesCall {
+    fn apply_full<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
+        let Self { blobhashes } = self;
+        ensure!(
+            ccx.ecx.spec_id() >= SpecId::CANCUN,
+            "`blobhash` is not supported before the Cancun hard fork; \
+             see EIP-4844: https://eips.ethereum.org/EIPS/eip-4844"
+        );
+        ccx.ecx.env.tx.blob_hashes.clone_from(blobhashes);
+        Ok(Default::default())
+    }
+}
+
+impl Cheatcode for getBlobhashesCall {
+    fn apply_full<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
+        let Self {} = self;
+        ensure!(
+            ccx.ecx.spec_id() >= SpecId::CANCUN,
+            "`blobhash` is not supported before the Cancun hard fork; \
+             see EIP-4844: https://eips.ethereum.org/EIPS/eip-4844"
+        );
+        Ok(ccx.ecx.env.tx.blob_hashes.clone().abi_encode())
+    }
+}
+
 impl Cheatcode for rollCall {
     fn apply_full<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
         let Self { newHeight } = self;

testdata/cancun/cheats/Blobhashes.t.sol

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+pragma solidity ^0.8.25;
+
+import "ds-test/test.sol";
+import "cheats/Vm.sol";
+
+contract BlobhashesTest is DSTest {
+    Vm constant vm = Vm(HEVM_ADDRESS);
+
+    function testSetAndGetBlobhashes() public {
+        bytes32[] memory blobhashes = new bytes32[](2);
+        blobhashes[0] = bytes32(0x0000000000000000000000000000000000000000000000000000000000000001);
+        blobhashes[1] = bytes32(0x0000000000000000000000000000000000000000000000000000000000000002);
+        vm.blobhashes(blobhashes);
+
+        bytes32[] memory gotBlobhashes = vm.getBlobhashes();
+        assertEq(gotBlobhashes[0], blobhashes[0]);
+        assertEq(gotBlobhashes[1], blobhashes[1]);
+    }
+}