ethclient/simulated: move backend to new package

accounts/abi/bind/backends/simulated.go

@@ -17,152 +17,19 @@
 package backends
 
 import (
-	"context"
-	"math"
-	"time"
-
-	"github.com/ethereum/go-ethereum"
-	"github.com/ethereum/go-ethereum/accounts/abi/bind"
-	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/ethclient/simulated"
-	"github.com/ethereum/go-ethereum/eth/catalyst"
-	"github.com/ethereum/go-ethereum/eth/downloader"
-	"github.com/ethereum/go-ethereum/eth/ethconfig"
-	"github.com/ethereum/go-ethereum/eth/filters"
-	"github.com/ethereum/go-ethereum/ethclient"
-	"github.com/ethereum/go-ethereum/node"
-	"github.com/ethereum/go-ethereum/p2p"
-	"github.com/ethereum/go-ethereum/params"
-	"github.com/ethereum/go-ethereum/rpc"
 )
 
-var _ bind.ContractBackend = (SimulatedBackend)(nil)
+type SimulatedBackend struct {
-var _ bind.ContractBackend = (*simBackend)(nil)
+	simulated.Backend
-
-type SimChainManagement interface {
-	// Commit seals a block and moves the chain forward to a new empty block.
-	Commit() common.Hash
-
-	// Rollback un-sends previously added transactions.
-	Rollback()
-
-	// Fork sets the head to a new block, which is based on the provided parentHash.
-	Fork(ctx context.Context, parentHash common.Hash) error
-
-	// AdjustTime changes the block timestamp.
-	AdjustTime(adjustment time.Duration) error
-
-	// Close closes the backend. You need to call this to clean up resources.
-	Close() error
 }
 
-// SimulatedBackend all interfaces in the ethereum package, but is based on a
+// New creates a new binding backend using a simulated blockchain
-// simulated blockchain. It is intended for testing purposes.
-type SimulatedBackend interface {
-	SimChainManagement
-
-	// The backend implements all interfaces in the ethereum package.
-	ethereum.BlockNumberReader
-	ethereum.ChainReader
-	ethereum.ChainStateReader
-	ethereum.ContractCaller
-	ethereum.GasEstimator
-	ethereum.GasPricer
-	ethereum.GasPricer1559
-	ethereum.LogFilterer
-	ethereum.PendingStateReader
-	ethereum.PendingContractCaller
-	ethereum.TransactionReader
-	ethereum.TransactionSender
-	ethereum.ChainIDReader
-}
-
-type simBackend struct {
-	eth *eth.Ethereum
-	*catalyst.SimulatedBeacon
-	*ethclient.Client
-}
-
-// NewSimulatedBackend creates a new binding backend using a simulated blockchain
 // for testing purposes.
 // A simulated backend always uses chainID 1337.
+//
+// Deprecated: please use simulated.Backend instead
 func NewSimulatedBackend(alloc core.GenesisAlloc, gasLimit uint64) SimulatedBackend {
-	// Setup the node object
+	return SimulatedBackend{simulated.New(alloc, gasLimit)}
-	nodeConf := node.DefaultConfig
-	nodeConf.DataDir = ""
-	nodeConf.P2P = p2p.Config{DiscAddr: "", ListenAddr: ""}
-	stack, err := node.New(&nodeConf)
-	if err != nil {
-		// This should never happen, if it does, please open an issue
-		panic(err)
-	}
-
-	// Setup ethereum
-	genesis := core.Genesis{
-		Config:   params.AllDevChainProtocolChanges,
-		GasLimit: gasLimit,
-		Alloc:    alloc,
-	}
-	conf := ethconfig.Defaults
-	conf.Genesis = &genesis
-	conf.SyncMode = downloader.FullSync
-	sim, err := NewSimWithNode(stack, &conf, math.MaxUint64)
-	if err != nil {
-		// This should never happen, if it does, please open an issue
-		panic(err)
-	}
-	return sim
-}
-
-// NewSimWithNode sets up a simulated backend on an existing node
-// this allows users to do persistent simulations.
-// The provided node must not be started and will be started by NewSimWithNode
-func NewSimWithNode(stack *node.Node, conf *eth.Config, blockPeriod uint64) (SimulatedBackend, error) {
-	backend, err := eth.New(stack, conf)
-	if err != nil {
-		return nil, err
-	}
-
-	// Register the filter system
-	filterSystem := filters.NewFilterSystem(backend.APIBackend, filters.Config{})
-	stack.RegisterAPIs([]rpc.API{{
-		Namespace: "eth",
-		Service:   filters.NewFilterAPI(filterSystem, false),
-	}})
-
-	// Start the node
-	if err := stack.Start(); err != nil {
-		return nil, err
-	}
-
-	// Set up the simulated beacon
-	beacon, err := catalyst.NewSimulatedBeacon(blockPeriod, backend)
-	if err != nil {
-		return nil, err
-	}
-
-	// Reorg our chain back to genesis
-	if err := beacon.Fork(context.Background(), backend.BlockChain().GetCanonicalHash(0)); err != nil {
-		return nil, err
-	}
-
-	return &simBackend{
-		eth:             backend,
-		SimulatedBeacon: beacon,
-		Client:          ethclient.NewClient(stack.Attach()),
-	}, nil
-}
-
-func (n *simBackend) Close() error {
-	if n.Client != nil {
-		n.Client.Close()
-		n.Client = nil
-	}
-	if n.SimulatedBeacon != nil {
-		err := n.SimulatedBeacon.Stop()
-		n.SimulatedBeacon = nil
-		return err
-	}
-	return nil
 }

ethclient/simulated/backend.go

@@ -0,0 +1,168 @@
+// Copyright 2023 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package simulated
+
+import (
+	"context"
+	"math"
+	"time"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/catalyst"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/eth/ethconfig"
+	"github.com/ethereum/go-ethereum/eth/filters"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rpc"
+)
+
+var _ bind.ContractBackend = (Backend)(nil)
+var _ bind.ContractBackend = (*simBackend)(nil)
+
+type SimChainManagement interface {
+	// Commit seals a block and moves the chain forward to a new empty block.
+	Commit() common.Hash
+
+	// Rollback un-sends previously added transactions.
+	Rollback()
+
+	// Fork sets the head to a new block, which is based on the provided parentHash.
+	Fork(ctx context.Context, parentHash common.Hash) error
+
+	// AdjustTime changes the block timestamp.
+	AdjustTime(adjustment time.Duration) error
+
+	// Close closes the backend. You need to call this to clean up resources.
+	Close() error
+}
+
+// Backend all interfaces in the ethereum package, but is based on a
+// simulated blockchain. It is intended for testing purposes.
+type Backend interface {
+	SimChainManagement
+
+	// The backend implements all interfaces in the ethereum package.
+	ethereum.BlockNumberReader
+	ethereum.ChainReader
+	ethereum.ChainStateReader
+	ethereum.ContractCaller
+	ethereum.GasEstimator
+	ethereum.GasPricer
+	ethereum.GasPricer1559
+	ethereum.LogFilterer
+	ethereum.PendingStateReader
+	ethereum.PendingContractCaller
+	ethereum.TransactionReader
+	ethereum.TransactionSender
+	ethereum.ChainIDReader
+}
+
+type simBackend struct {
+	eth *eth.Ethereum
+	*catalyst.SimulatedBeacon
+	*ethclient.Client
+}
+
+// New creates a new binding backend using a simulated blockchain
+// for testing purposes.
+// A simulated backend always uses chainID 1337.
+func New(alloc core.GenesisAlloc, gasLimit uint64) Backend {
+	// Setup the node object
+	nodeConf := node.DefaultConfig
+	nodeConf.DataDir = ""
+	nodeConf.P2P = p2p.Config{DiscAddr: "", ListenAddr: ""}
+	stack, err := node.New(&nodeConf)
+	if err != nil {
+		// This should never happen, if it does, please open an issue
+		panic(err)
+	}
+
+	// Setup ethereum
+	genesis := core.Genesis{
+		Config:   params.AllDevChainProtocolChanges,
+		GasLimit: gasLimit,
+		Alloc:    alloc,
+	}
+	conf := ethconfig.Defaults
+	conf.Genesis = &genesis
+	conf.SyncMode = downloader.FullSync
+	sim, err := NewWithNode(stack, &conf, math.MaxUint64)
+	if err != nil {
+		// This should never happen, if it does, please open an issue
+		panic(err)
+	}
+	return sim
+}
+
+// NewWithNode sets up a simulated backend on an existing node
+// this allows users to do persistent simulations.
+// The provided node must not be started and will be started by NewWithNode
+func NewWithNode(stack *node.Node, conf *eth.Config, blockPeriod uint64) (Backend, error) {
+	backend, err := eth.New(stack, conf)
+	if err != nil {
+		return nil, err
+	}
+
+	// Register the filter system
+	filterSystem := filters.NewFilterSystem(backend.APIBackend, filters.Config{})
+	stack.RegisterAPIs([]rpc.API{{
+		Namespace: "eth",
+		Service:   filters.NewFilterAPI(filterSystem, false),
+	}})
+
+	// Start the node
+	if err := stack.Start(); err != nil {
+		return nil, err
+	}
+
+	// Set up the simulated beacon
+	beacon, err := catalyst.NewSimulatedBeacon(blockPeriod, backend)
+	if err != nil {
+		return nil, err
+	}
+
+	// Reorg our chain back to genesis
+	if err := beacon.Fork(context.Background(), backend.BlockChain().GetCanonicalHash(0)); err != nil {
+		return nil, err
+	}
+
+	return &simBackend{
+		eth:             backend,
+		SimulatedBeacon: beacon,
+		Client:          ethclient.NewClient(stack.Attach()),
+	}, nil
+}
+
+func (n *simBackend) Close() error {
+	if n.Client != nil {
+		n.Client.Close()
+		n.Client = nil
+	}
+	if n.SimulatedBeacon != nil {
+		err := n.SimulatedBeacon.Stop()
+		n.SimulatedBeacon = nil
+		return err
+	}
+	return nil
+}

ethclient/simulated/backend_test.go

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
-package backends
+package simulated
 
 import (
 	"context"
@@ -36,15 +36,15 @@ var (
 	testAddr   = crypto.PubkeyToAddress(testKey.PublicKey)
 )
 
-func simTestBackend(testAddr common.Address) SimulatedBackend {
+func simTestBackend(testAddr common.Address) Backend {
-	return NewSimulatedBackend(
+	return New(
 		core.GenesisAlloc{
 			testAddr: {Balance: big.NewInt(10000000000000000)},
 		}, 10000000,
 	)
 }
 
-func newTx(sim SimulatedBackend, key *ecdsa.PrivateKey) (*types.Transaction, error) {
+func newTx(sim Backend, key *ecdsa.PrivateKey) (*types.Transaction, error) {
 	// create a signed transaction to send
 	head, _ := sim.HeaderByNumber(context.Background(), nil) // Should be child's, good enough
 	gasPrice := new(big.Int).Add(head.BaseFee, big.NewInt(1))
@@ -67,7 +67,7 @@ func newTx(sim SimulatedBackend, key *ecdsa.PrivateKey) (*types.Transaction, err
 }
 
 func TestNewSim(t *testing.T) {
-	sim := NewSimulatedBackend(core.GenesisAlloc{}, 30_000_000)
+	sim := New(core.GenesisAlloc{}, 30_000_000)
 	num, err := sim.BlockNumber(context.Background())
 	if err != nil {
 		t.Fatal(err)
@@ -87,7 +87,7 @@ func TestNewSim(t *testing.T) {
 }
 
 func TestAdjustTime(t *testing.T) {
-	sim := NewSimulatedBackend(core.GenesisAlloc{}, 10_000_000)
+	sim := New(core.GenesisAlloc{}, 10_000_000)
 	defer sim.Close()
 
 	block1, _ := sim.BlockByNumber(context.Background(), nil)