test: vm.Hooks.OverrideNewEVMArgs

Author: ARR4N

core/vm/evm.libevm_test.go

@@ -0,0 +1,32 @@
+package vm
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/stretchr/testify/require"
+)
+
+type chainIDOverrider struct {
+	chainID int64
+}
+
+func (o chainIDOverrider) OverrideNewEVMArgs(BlockContext, TxContext, StateDB, *params.ChainConfig, Config) (BlockContext, TxContext, StateDB, *params.ChainConfig, Config) {
+	return BlockContext{}, TxContext{}, nil, &params.ChainConfig{ChainID: big.NewInt(o.chainID)}, Config{}
+}
+
+func TestOverrideNewEVMArgs(t *testing.T) {
+	// The OverrideNewEVMArgs hook accepts and returns all arguments to
+	// NewEVM(), in order. Here we lock in our assumption of that order. If this
+	// breaks then the Hooks.OverrideNewEVMArgs() signature MUST be changed to
+	// match.
+	var _ func(BlockContext, TxContext, StateDB, *params.ChainConfig, Config) *EVM = NewEVM
+
+	const chainID = 13579
+	libevmHooks = nil
+	RegisterHooks(chainIDOverrider{chainID: chainID})
+
+	got := NewEVM(BlockContext{}, TxContext{}, nil, nil, Config{}).ChainConfig().ChainID
+	require.Equal(t, big.NewInt(chainID), got)
+}