go-ethereum/libevm/ethtest/evm.go

61 lines
1.5 KiB
Go

// Package ethtest provides utility functions for use in testing
// Ethereum-related functionality.
package ethtest
import (
"testing"
"github.com/stretchr/testify/require"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/params"
)
// NewZeroEVM returns a new EVM backed by a [rawdb.NewMemoryDatabase]; all other
// arguments to [vm.NewEVM] are the zero values of their respective types,
// except for the use of [core.CanTransfer] and [core.Transfer] instead of nil
// functions.
func NewZeroEVM(tb testing.TB, opts ...EVMOption) (*state.StateDB, *vm.EVM) {
tb.Helper()
sdb, err := state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
require.NoError(tb, err, "state.New()")
vm := vm.NewEVM(
vm.BlockContext{
CanTransfer: core.CanTransfer,
Transfer: core.Transfer,
},
vm.TxContext{},
sdb,
&params.ChainConfig{},
vm.Config{},
)
for _, o := range opts {
o.apply(vm)
}
return sdb, vm
}
// An EVMOption configures the EVM returned by [NewZeroEVM].
type EVMOption interface {
apply(*vm.EVM)
}
type funcOption func(*vm.EVM)
var _ EVMOption = funcOption(nil)
func (f funcOption) apply(vm *vm.EVM) { f(vm) }
// WithBlockContext overrides the default context.
func WithBlockContext(c vm.BlockContext) EVMOption {
return funcOption(func(vm *vm.EVM) {
vm.Context = c
})
}