feat: PrecompileEnvironment.ChainConfig() (#32)

core/vm/contracts.libevm.go

@@ -94,6 +94,7 @@ func (p statefulPrecompile) Run([]byte) ([]byte, error) {
 // A PrecompileEnvironment provides information about the context in which a
 // precompiled contract is being run.
 type PrecompileEnvironment interface {
+	ChainConfig() *params.ChainConfig
 	Rules() params.Rules
 	ReadOnly() bool
 	// StateDB will be non-nil i.f.f !ReadOnly().
@@ -121,7 +122,8 @@ type PrecompileEnvironment interface {
 
 var _ PrecompileEnvironment = (*evmCallArgs)(nil)
 
-func (args *evmCallArgs) Rules() params.Rules { return args.evm.chainRules }
+func (args *evmCallArgs) ChainConfig() *params.ChainConfig { return args.evm.chainConfig }
+func (args *evmCallArgs) Rules() params.Rules              { return args.evm.chainRules }
 
 func (args *evmCallArgs) ReadOnly() bool {
 	if args.readWrite == inheritReadOnly {

core/vm/contracts.libevm_test.go

@@ -84,6 +84,7 @@ func TestPrecompileOverride(t *testing.T) {
 }
 
 type statefulPrecompileOutput struct {
+	ChainID                 *big.Int
 	Caller, Self            common.Address
 	StateValue              common.Hash
 	ReadOnly                bool
@@ -127,6 +128,7 @@ func TestNewStatefulPrecompile(t *testing.T) {
 
 		addrs := env.Addresses()
 		out := &statefulPrecompileOutput{
+			ChainID:     env.ChainConfig().ChainID,
 			Caller:      addrs.Caller,
 			Self:        addrs.Self,
 			StateValue:  env.ReadOnlyState().GetState(precompile, slot),
@@ -153,10 +155,17 @@ func TestNewStatefulPrecompile(t *testing.T) {
 	caller := rng.Address()
 	input := rng.Bytes(8)
 	value := rng.Hash()
+	chainID := rng.BigUint64()
 
-	state, evm := ethtest.NewZeroEVM(t, ethtest.WithBlockContext(
-		core.NewEVMBlockContext(header, nil, rng.AddressPtr()),
-	))
+	state, evm := ethtest.NewZeroEVM(
+		t,
+		ethtest.WithBlockContext(
+			core.NewEVMBlockContext(header, nil, rng.AddressPtr()),
+		),
+		ethtest.WithChainConfig(
+			&params.ChainConfig{ChainID: chainID},
+		),
+	)
 	state.SetState(precompile, slot, value)
 
 	tests := []struct {
@@ -199,6 +208,7 @@ func TestNewStatefulPrecompile(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			wantReturnData := statefulPrecompileOutput{
+				ChainID:     chainID,
 				Caller:      caller,
 				Self:        precompile,
 				StateValue:  value,

libevm/ethtest/evm.go

@@ -25,7 +25,7 @@ func NewZeroEVM(tb testing.TB, opts ...EVMOption) (*state.StateDB, *vm.EVM) {
 	sdb, err := state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
 	require.NoError(tb, err, "state.New()")
 
-	vm := vm.NewEVM(
+	args := &evmConstructorArgs{
 		vm.BlockContext{
 			CanTransfer: core.CanTransfer,
 			Transfer:    core.Transfer,
@@ -34,28 +34,49 @@ func NewZeroEVM(tb testing.TB, opts ...EVMOption) (*state.StateDB, *vm.EVM) {
 		sdb,
 		&params.ChainConfig{},
 		vm.Config{},
-	)
+	}
 	for _, o := range opts {
-		o.apply(vm)
+		o.apply(args)
 	}
 
-	return sdb, vm
+	return sdb, vm.NewEVM(
+		args.blockContext,
+		args.txContext,
+		args.stateDB,
+		args.chainConfig,
+		args.config,
+	)
+}
+
+type evmConstructorArgs struct {
+	blockContext vm.BlockContext
+	txContext    vm.TxContext
+	stateDB      vm.StateDB
+	chainConfig  *params.ChainConfig
+	config       vm.Config
 }
 
 // An EVMOption configures the EVM returned by [NewZeroEVM].
 type EVMOption interface {
-	apply(*vm.EVM)
+	apply(*evmConstructorArgs)
 }
 
-type funcOption func(*vm.EVM)
+type funcOption func(*evmConstructorArgs)
 
 var _ EVMOption = funcOption(nil)
 
-func (f funcOption) apply(vm *vm.EVM) { f(vm) }
+func (f funcOption) apply(args *evmConstructorArgs) { f(args) }
 
 // WithBlockContext overrides the default context.
 func WithBlockContext(c vm.BlockContext) EVMOption {
-	return funcOption(func(vm *vm.EVM) {
-		vm.Context = c
+	return funcOption(func(args *evmConstructorArgs) {
+		args.blockContext = c
+	})
+}
+
+// WithBlockContext overrides the default context.
+func WithChainConfig(c *params.ChainConfig) EVMOption {
+	return funcOption(func(args *evmConstructorArgs) {
+		args.chainConfig = c
 	})
 }