feat(forge): blobbasefee cheatcode (#7598)

* feat(forge): blobbasefee cheatcode

* updated comments

* nits

* moved test

* chore: add cancun test

---------

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

crates/cheatcodes/spec/src/vm.rs

@@ -402,6 +402,17 @@ interface Vm {
  #[cheatcode(group = Evm, safety = Safe)]
  function getBlockTimestamp() external view returns (uint256 timestamp);
 
+ /// Sets `block.blobbasefee`
+ #[cheatcode(group = Evm, safety = Unsafe)]
+ function blobBaseFee(uint256 newBlobBaseFee) external;
+
+ /// Gets the current `block.blobbasefee`.
+ /// You should use this instead of `block.blobbasefee` if you use `vm.blobBaseFee`, as `block.blobbasefee` is assumed to be constant across a transaction,
+ /// and as a result will get optimized out by the compiler.
+ /// See https://github.com/foundry-rs/foundry/issues/6180
+ #[cheatcode(group = Evm, safety = Safe)]
+ function getBlobBaseFee() external view returns (uint256 blobBaseFee);
+
  // -------- Account State --------
 
  /// Sets an address' balance.

crates/cheatcodes/src/evm.rs

@@ -328,6 +328,26 @@ impl Cheatcode for getBlockTimestampCall {
  }
 }
 
+impl Cheatcode for blobBaseFeeCall {
+ fn apply_full<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
+ let Self { newBlobBaseFee } = self;
+ ensure!(
+ ccx.ecx.spec_id() >= SpecId::CANCUN,
+ "`blobBaseFee` is not supported before the Cancun hard fork; \
+ see EIP-4844: https://eips.ethereum.org/EIPS/eip-4844"
+ );
+ ccx.ecx.env.block.set_blob_excess_gas_and_price((*newBlobBaseFee).to());
+ Ok(Default::default())
+ }
+}
+
+impl Cheatcode for getBlobBaseFeeCall {
+ fn apply_full<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
+ let Self {} = self;
+ Ok(ccx.ecx.env.block.get_blob_excess_gas().unwrap_or(0).abi_encode())
+ }
+}
+
 impl Cheatcode for dealCall {
  fn apply_full<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
  let Self { account: address, newBalance: new_balance } = *self;

crates/forge/tests/it/cheats.rs

@@ -2,7 +2,10 @@
 
 use crate::{
  config::*,
- test_helpers::{ForgeTestData, RE_PATH_SEPARATOR, TEST_DATA_DEFAULT, TEST_DATA_MULTI_VERSION},
+ test_helpers::{
+ ForgeTestData, RE_PATH_SEPARATOR, TEST_DATA_CANCUN, TEST_DATA_DEFAULT,
+ TEST_DATA_MULTI_VERSION,
+ },
 };
 use foundry_config::{fs_permissions::PathPermission, FsPermissions};
 use foundry_test_utils::Filter;
@@ -50,3 +53,8 @@ async fn test_cheats_local_default_isolated() {
 async fn test_cheats_local_multi_version() {
  test_cheats_local(&TEST_DATA_MULTI_VERSION).await
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_cheats_local_cancun() {
+ test_cheats_local(&TEST_DATA_CANCUN).await
+}

crates/forge/tests/it/test_helpers.rs

@@ -2,8 +2,8 @@
 
 use alloy_primitives::U256;
 use forge::{
- inspectors::CheatsConfig, MultiContractRunner, MultiContractRunnerBuilder, TestOptions,
- TestOptionsBuilder,
+ inspectors::CheatsConfig, revm::primitives::SpecId, MultiContractRunner,
+ MultiContractRunnerBuilder, TestOptions, TestOptionsBuilder,
 };
 use foundry_compilers::{
  artifacts::{Libraries, Settings},
@@ -46,6 +46,11 @@ impl fmt::Display for ForgeTestProfile {
 }
 
 impl ForgeTestProfile {
+ /// Returns true if the profile is Cancun.
+ pub fn is_cancun(&self) -> bool {
+ matches!(self, Self::Cancun)
+ }
+
  pub fn root(&self) -> PathBuf {
  PathBuf::from(TESTDATA)
  }
@@ -147,7 +152,7 @@ impl ForgeTestProfile {
  "fork/Fork.t.sol:DssExecLib:0xfD88CeE74f7D78697775aBDAE53f9Da1559728E4".to_string(),
  ];
 
- if matches!(self, Self::Cancun) {
+ if self.is_cancun() {
  config.evm_version = EvmVersion::Cancun;
  }
 
@@ -162,6 +167,7 @@ pub struct ForgeTestData {
  pub test_opts: TestOptions,
  pub evm_opts: EvmOpts,
  pub config: Config,
+ pub profile: ForgeTestProfile,
 }
 
 impl ForgeTestData {
@@ -175,15 +181,20 @@ impl ForgeTestData {
  let config = profile.config();
  let evm_opts = profile.evm_opts();
 
- Self { project, output, test_opts, evm_opts, config }
+ Self { project, output, test_opts, evm_opts, config, profile }
  }
 
  /// Builds a base runner
  pub fn base_runner(&self) -> MultiContractRunnerBuilder {
  init_tracing();
- MultiContractRunnerBuilder::default()
+ let mut runner = MultiContractRunnerBuilder::default()
  .sender(self.evm_opts.sender)
- .with_test_options(self.test_opts.clone())
+ .with_test_options(self.test_opts.clone());
+ if self.profile.is_cancun() {
+ runner = runner.evm_spec(SpecId::CANCUN);
+ }
+
+ runner
  }
 
  /// Builds a non-tracing runner

testdata/cancun/cheats/BlobBaseFee.t.sol

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+pragma solidity ^0.8.25;
+
+import "ds-test/test.sol";
+import "cheats/Vm.sol";
+
+contract BlobBaseFeeTest is DSTest {
+ Vm constant vm = Vm(HEVM_ADDRESS);
+
+ function test_blob_base_fee() public {
+ vm.blobBaseFee(6969);
+ assertEq(vm.getBlobBaseFee(), 6969);
+ }
+}