github.com/ethereum/go-ethereum@v1.16.1/core/txpool/legacypool/legacypool_test.go

// Copyright 2015 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 legacypool

import (
	"crypto/ecdsa"
	crand "crypto/rand"
	"errors"
	"fmt"
	"math/big"
	"math/rand"
	"slices"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/core/state"
	"github.com/ethereum/go-ethereum/core/tracing"
	"github.com/ethereum/go-ethereum/core/txpool"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/core/vm"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/event"
	"github.com/ethereum/go-ethereum/params"
	"github.com/ethereum/go-ethereum/trie"
	"github.com/holiman/uint256"
)

var (
	// testTxPoolConfig is a transaction pool configuration without stateful disk
	// sideeffects used during testing.
	testTxPoolConfig Config

	// eip1559Config is a chain config with EIP-1559 enabled at block 0.
	eip1559Config *params.ChainConfig
)

func init() {
	testTxPoolConfig = DefaultConfig
	testTxPoolConfig.Journal = ""

	cpy := *params.TestChainConfig
	eip1559Config = &cpy
	eip1559Config.BerlinBlock = common.Big0
	eip1559Config.LondonBlock = common.Big0
}

type testBlockChain struct {
	config        *params.ChainConfig
	gasLimit      atomic.Uint64
	statedb       *state.StateDB
	chainHeadFeed *event.Feed
}

func newTestBlockChain(config *params.ChainConfig, gasLimit uint64, statedb *state.StateDB, chainHeadFeed *event.Feed) *testBlockChain {
	bc := testBlockChain{config: config, statedb: statedb, chainHeadFeed: new(event.Feed)}
	bc.gasLimit.Store(gasLimit)
	return &bc
}

func (bc *testBlockChain) Config() *params.ChainConfig {
	return bc.config
}

func (bc *testBlockChain) CurrentBlock() *types.Header {
	return &types.Header{
		Number:     new(big.Int),
		Difficulty: common.Big0,
		GasLimit:   bc.gasLimit.Load(),
	}
}

func (bc *testBlockChain) GetBlock(hash common.Hash, number uint64) *types.Block {
	return types.NewBlock(bc.CurrentBlock(), nil, nil, trie.NewStackTrie(nil))
}

func (bc *testBlockChain) StateAt(common.Hash) (*state.StateDB, error) {
	return bc.statedb, nil
}

func (bc *testBlockChain) SubscribeChainHeadEvent(ch chan<- core.ChainHeadEvent) event.Subscription {
	return bc.chainHeadFeed.Subscribe(ch)
}

func transaction(nonce uint64, gaslimit uint64, key *ecdsa.PrivateKey) *types.Transaction {
	return pricedTransaction(nonce, gaslimit, big.NewInt(1), key)
}

func pricedTransaction(nonce uint64, gaslimit uint64, gasprice *big.Int, key *ecdsa.PrivateKey) *types.Transaction {
	tx, _ := types.SignTx(types.NewTransaction(nonce, common.Address{}, big.NewInt(100), gaslimit, gasprice, nil), types.HomesteadSigner{}, key)
	return tx
}

// pricedDataTransaction generates a signed transaction with fixed-size data,
// and ensures that the resulting signature components (r and s) are exactly 32 bytes each,
// producing transactions with deterministic size.
//
// This avoids variability in transaction size caused by leading zeros being omitted in
// RLP encoding of r/s. Since r and s are derived from ECDSA, they occasionally have leading
// zeros and thus can be shorter than 32 bytes.
//
// For example:
//
//	r: 0 leading zeros, bytesSize: 32, bytes: [221 ... 101]
//	s: 1 leading zeros, bytesSize: 31, bytes: [0 75 ... 47]
func pricedDataTransaction(nonce uint64, gaslimit uint64, gasprice *big.Int, key *ecdsa.PrivateKey, dataBytes uint64) *types.Transaction {
	var tx *types.Transaction

	// 10 attempts is statistically sufficient since leading zeros in ECDSA signatures are rare and randomly distributed.
	var retryTimes = 10
	for i := 0; i < retryTimes; i++ {
		data := make([]byte, dataBytes)
		crand.Read(data)

		tx, _ = types.SignTx(types.NewTransaction(nonce, common.Address{}, big.NewInt(0), gaslimit, gasprice, data), types.HomesteadSigner{}, key)
		_, r, s := tx.RawSignatureValues()
		if len(r.Bytes()) == 32 && len(s.Bytes()) == 32 {
			break
		}
	}
	return tx
}

func dynamicFeeTx(nonce uint64, gaslimit uint64, gasFee *big.Int, tip *big.Int, key *ecdsa.PrivateKey) *types.Transaction {
	tx, _ := types.SignNewTx(key, types.LatestSignerForChainID(params.TestChainConfig.ChainID), &types.DynamicFeeTx{
		ChainID:    params.TestChainConfig.ChainID,
		Nonce:      nonce,
		GasTipCap:  tip,
		GasFeeCap:  gasFee,
		Gas:        gaslimit,
		To:         &common.Address{},
		Value:      big.NewInt(100),
		Data:       nil,
		AccessList: nil,
	})
	return tx
}

type unsignedAuth struct {
	nonce uint64
	key   *ecdsa.PrivateKey
}

func setCodeTx(nonce uint64, key *ecdsa.PrivateKey, unsigned []unsignedAuth) *types.Transaction {
	return pricedSetCodeTx(nonce, 250000, uint256.NewInt(1000), uint256.NewInt(1), key, unsigned)
}

func pricedSetCodeTx(nonce uint64, gaslimit uint64, gasFee, tip *uint256.Int, key *ecdsa.PrivateKey, unsigned []unsignedAuth) *types.Transaction {
	var authList []types.SetCodeAuthorization
	for _, u := range unsigned {
		auth, _ := types.SignSetCode(u.key, types.SetCodeAuthorization{
			ChainID: *uint256.MustFromBig(params.TestChainConfig.ChainID),
			Address: common.Address{0x42},
			Nonce:   u.nonce,
		})
		authList = append(authList, auth)
	}
	return pricedSetCodeTxWithAuth(nonce, gaslimit, gasFee, tip, key, authList)
}

func pricedSetCodeTxWithAuth(nonce uint64, gaslimit uint64, gasFee, tip *uint256.Int, key *ecdsa.PrivateKey, authList []types.SetCodeAuthorization) *types.Transaction {
	return types.MustSignNewTx(key, types.LatestSignerForChainID(params.TestChainConfig.ChainID), &types.SetCodeTx{
		ChainID:    uint256.MustFromBig(params.TestChainConfig.ChainID),
		Nonce:      nonce,
		GasTipCap:  tip,
		GasFeeCap:  gasFee,
		Gas:        gaslimit,
		To:         common.Address{},
		Value:      uint256.NewInt(100),
		Data:       nil,
		AccessList: nil,
		AuthList:   authList,
	})
}

func setupPool() (*LegacyPool, *ecdsa.PrivateKey) {
	return setupPoolWithConfig(params.TestChainConfig)
}

// reserver is a utility struct to sanity check that accounts are
// properly reserved by the blobpool (no duplicate reserves or unreserves).
type reserver struct {
	accounts map[common.Address]struct{}
	lock     sync.RWMutex
}

func newReserver() txpool.Reserver {
	return &reserver{accounts: make(map[common.Address]struct{})}
}

func (r *reserver) Hold(addr common.Address) error {
	r.lock.Lock()
	defer r.lock.Unlock()
	if _, exists := r.accounts[addr]; exists {
		panic("already reserved")
	}
	r.accounts[addr] = struct{}{}
	return nil
}

func (r *reserver) Release(addr common.Address) error {
	r.lock.Lock()
	defer r.lock.Unlock()
	if _, exists := r.accounts[addr]; !exists {
		panic("not reserved")
	}
	delete(r.accounts, addr)
	return nil
}

func (r *reserver) Has(address common.Address) bool {
	return false // reserver only supports a single pool
}

func setupPoolWithConfig(config *params.ChainConfig) (*LegacyPool, *ecdsa.PrivateKey) {
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(config, 10000000, statedb, new(event.Feed))

	key, _ := crypto.GenerateKey()
	pool := New(testTxPoolConfig, blockchain)
	if err := pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver()); err != nil {
		panic(err)
	}
	// wait for the pool to initialize
	<-pool.initDoneCh
	return pool, key
}

// validatePoolInternals checks various consistency invariants within the pool.
func validatePoolInternals(pool *LegacyPool) error {
	pool.mu.RLock()
	defer pool.mu.RUnlock()

	// Ensure the total transaction set is consistent with pending + queued
	pending, queued := pool.stats()
	if total := pool.all.Count(); total != pending+queued {
		return fmt.Errorf("total transaction count %d != %d pending + %d queued", total, pending, queued)
	}
	pool.priced.Reheap()
	priced, remote := pool.priced.urgent.Len()+pool.priced.floating.Len(), pool.all.Count()
	if priced != remote {
		return fmt.Errorf("total priced transaction count %d != %d", priced, remote)
	}
	// Ensure the next nonce to assign is the correct one
	for addr, txs := range pool.pending {
		// Find the last transaction
		var last uint64
		for nonce := range txs.txs.items {
			if last < nonce {
				last = nonce
			}
		}
		if nonce := pool.pendingNonces.get(addr); nonce != last+1 {
			return fmt.Errorf("pending nonce mismatch: have %v, want %v", nonce, last+1)
		}
	}
	// Ensure all auths in pool are tracked
	for _, tx := range pool.all.txs {
		for _, addr := range tx.SetCodeAuthorities() {
			list := pool.all.auths[addr]
			if i := slices.Index(list, tx.Hash()); i < 0 {
				return fmt.Errorf("authority not tracked: addr %s, tx %s", addr, tx.Hash())
			}
		}
	}
	// Ensure all auths in pool have an associated tx.
	for addr, hashes := range pool.all.auths {
		for _, hash := range hashes {
			if _, ok := pool.all.txs[hash]; !ok {
				return fmt.Errorf("dangling authority, missing originating tx: addr %s, hash %s", addr, hash.Hex())
			}
		}
	}
	return nil
}

// validateEvents checks that the correct number of transaction addition events
// were fired on the pool's event feed.
func validateEvents(events chan core.NewTxsEvent, count int) error {
	var received []*types.Transaction

	for len(received) < count {
		select {
		case ev := <-events:
			received = append(received, ev.Txs...)
		case <-time.After(time.Second):
			return fmt.Errorf("event #%d not fired", len(received))
		}
	}
	if len(received) > count {
		return fmt.Errorf("more than %d events fired: %v", count, received[count:])
	}
	select {
	case ev := <-events:
		return fmt.Errorf("more than %d events fired: %v", count, ev.Txs)

	case <-time.After(50 * time.Millisecond):
		// This branch should be "default", but it's a data race between goroutines,
		// reading the event channel and pushing into it, so better wait a bit ensuring
		// really nothing gets injected.
	}
	return nil
}

func deriveSender(tx *types.Transaction) (common.Address, error) {
	return types.Sender(types.HomesteadSigner{}, tx)
}

type testChain struct {
	*testBlockChain
	address common.Address
	trigger *bool
}

// testChain.State() is used multiple times to reset the pending state.
// when simulate is true it will create a state that indicates
// that tx0 and tx1 are included in the chain.
func (c *testChain) State() (*state.StateDB, error) {
	// delay "state change" by one. The tx pool fetches the
	// state multiple times and by delaying it a bit we simulate
	// a state change between those fetches.
	stdb := c.statedb
	if *c.trigger {
		c.statedb, _ = state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
		// simulate that the new head block included tx0 and tx1
		c.statedb.SetNonce(c.address, 2, tracing.NonceChangeUnspecified)
		c.statedb.SetBalance(c.address, new(uint256.Int).SetUint64(params.Ether), tracing.BalanceChangeUnspecified)
		*c.trigger = false
	}
	return stdb, nil
}

// This test simulates a scenario where a new block is imported during a
// state reset and tests whether the pending state is in sync with the
// block head event that initiated the resetState().
func TestStateChangeDuringReset(t *testing.T) {
	t.Parallel()

	var (
		key, _     = crypto.GenerateKey()
		address    = crypto.PubkeyToAddress(key.PublicKey)
		statedb, _ = state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
		trigger    = false
	)

	// setup pool with 2 transaction in it
	statedb.SetBalance(address, new(uint256.Int).SetUint64(params.Ether), tracing.BalanceChangeUnspecified)
	blockchain := &testChain{newTestBlockChain(params.TestChainConfig, 1000000000, statedb, new(event.Feed)), address, &trigger}

	tx0 := transaction(0, 100000, key)
	tx1 := transaction(1, 100000, key)

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	nonce := pool.Nonce(address)
	if nonce != 0 {
		t.Fatalf("Invalid nonce, want 0, got %d", nonce)
	}

	pool.addRemotesSync([]*types.Transaction{tx0, tx1})

	nonce = pool.Nonce(address)
	if nonce != 2 {
		t.Fatalf("Invalid nonce, want 2, got %d", nonce)
	}

	// trigger state change in the background
	trigger = true
	<-pool.requestReset(nil, nil)

	nonce = pool.Nonce(address)
	if nonce != 2 {
		t.Fatalf("Invalid nonce, want 2, got %d", nonce)
	}
}

func testAddBalance(pool *LegacyPool, addr common.Address, amount *big.Int) {
	pool.mu.Lock()
	pool.currentState.AddBalance(addr, uint256.MustFromBig(amount), tracing.BalanceChangeUnspecified)
	pool.mu.Unlock()
}

func testSetNonce(pool *LegacyPool, addr common.Address, nonce uint64) {
	pool.mu.Lock()
	pool.currentState.SetNonce(addr, nonce, tracing.NonceChangeUnspecified)
	pool.mu.Unlock()
}

func TestInvalidTransactions(t *testing.T) {
	t.Parallel()

	pool, key := setupPool()
	defer pool.Close()

	tx := transaction(0, 100, key)
	from, _ := deriveSender(tx)

	// Intrinsic gas too low
	testAddBalance(pool, from, big.NewInt(1))
	if err, want := pool.addRemote(tx), core.ErrIntrinsicGas; !errors.Is(err, want) {
		t.Errorf("want %v have %v", want, err)
	}

	// Insufficient funds
	tx = transaction(0, 100000, key)
	if err, want := pool.addRemote(tx), core.ErrInsufficientFunds; !errors.Is(err, want) {
		t.Errorf("want %v have %v", want, err)
	}

	testSetNonce(pool, from, 1)
	testAddBalance(pool, from, big.NewInt(0xffffffffffffff))
	tx = transaction(0, 100000, key)
	if err, want := pool.addRemote(tx), core.ErrNonceTooLow; !errors.Is(err, want) {
		t.Errorf("want %v have %v", want, err)
	}

	tx = transaction(1, 100000, key)
	pool.gasTip.Store(uint256.NewInt(1000))
	if err, want := pool.addRemote(tx), txpool.ErrTxGasPriceTooLow; !errors.Is(err, want) {
		t.Errorf("want %v have %v", want, err)
	}
}

func TestQueue(t *testing.T) {
	t.Parallel()

	pool, key := setupPool()
	defer pool.Close()

	tx := transaction(0, 100, key)
	from, _ := deriveSender(tx)
	testAddBalance(pool, from, big.NewInt(1000))
	<-pool.requestReset(nil, nil)

	pool.enqueueTx(tx.Hash(), tx, true)
	<-pool.requestPromoteExecutables(newAccountSet(pool.signer, from))
	if len(pool.pending) != 1 {
		t.Error("expected valid txs to be 1 is", len(pool.pending))
	}

	tx = transaction(1, 100, key)
	from, _ = deriveSender(tx)
	testSetNonce(pool, from, 2)
	pool.enqueueTx(tx.Hash(), tx, true)

	<-pool.requestPromoteExecutables(newAccountSet(pool.signer, from))
	if _, ok := pool.pending[from].txs.items[tx.Nonce()]; ok {
		t.Error("expected transaction to be in tx pool")
	}
	if len(pool.queue) > 0 {
		t.Error("expected transaction queue to be empty. is", len(pool.queue))
	}
}

func TestQueue2(t *testing.T) {
	t.Parallel()

	pool, key := setupPool()
	defer pool.Close()

	tx1 := transaction(0, 100, key)
	tx2 := transaction(10, 100, key)
	tx3 := transaction(11, 100, key)
	from, _ := deriveSender(tx1)
	testAddBalance(pool, from, big.NewInt(1000))
	pool.reset(nil, nil)

	pool.enqueueTx(tx1.Hash(), tx1, true)
	pool.enqueueTx(tx2.Hash(), tx2, true)
	pool.enqueueTx(tx3.Hash(), tx3, true)

	pool.promoteExecutables([]common.Address{from})
	if len(pool.pending) != 1 {
		t.Error("expected pending length to be 1, got", len(pool.pending))
	}
	if pool.queue[from].Len() != 2 {
		t.Error("expected len(queue) == 2, got", pool.queue[from].Len())
	}
}

func TestNegativeValue(t *testing.T) {
	t.Parallel()

	pool, key := setupPool()
	defer pool.Close()

	tx, _ := types.SignTx(types.NewTransaction(0, common.Address{}, big.NewInt(-1), 100, big.NewInt(1), nil), types.HomesteadSigner{}, key)
	from, _ := deriveSender(tx)
	testAddBalance(pool, from, big.NewInt(1))
	if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrNegativeValue) {
		t.Error("expected", txpool.ErrNegativeValue, "got", err)
	}
}

func TestTipAboveFeeCap(t *testing.T) {
	t.Parallel()

	pool, key := setupPoolWithConfig(eip1559Config)
	defer pool.Close()

	tx := dynamicFeeTx(0, 100, big.NewInt(1), big.NewInt(2), key)

	if err := pool.addRemote(tx); !errors.Is(err, core.ErrTipAboveFeeCap) {
		t.Error("expected", core.ErrTipAboveFeeCap, "got", err)
	}
}

func TestVeryHighValues(t *testing.T) {
	t.Parallel()

	pool, key := setupPoolWithConfig(eip1559Config)
	defer pool.Close()

	veryBigNumber := big.NewInt(1)
	veryBigNumber.Lsh(veryBigNumber, 300)

	tx := dynamicFeeTx(0, 100, big.NewInt(1), veryBigNumber, key)
	if err := pool.addRemote(tx); !errors.Is(err, core.ErrTipVeryHigh) {
		t.Error("expected", core.ErrTipVeryHigh, "got", err)
	}

	tx2 := dynamicFeeTx(0, 100, veryBigNumber, big.NewInt(1), key)
	if err := pool.addRemote(tx2); !errors.Is(err, core.ErrFeeCapVeryHigh) {
		t.Error("expected", core.ErrFeeCapVeryHigh, "got", err)
	}
}

func TestChainFork(t *testing.T) {
	t.Parallel()

	pool, key := setupPool()
	defer pool.Close()

	addr := crypto.PubkeyToAddress(key.PublicKey)
	resetState := func() {
		statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
		statedb.AddBalance(addr, uint256.NewInt(100000000000000), tracing.BalanceChangeUnspecified)

		pool.chain = newTestBlockChain(pool.chainconfig, 1000000, statedb, new(event.Feed))
		<-pool.requestReset(nil, nil)
	}
	resetState()

	tx := transaction(0, 100000, key)
	if _, err := pool.add(tx); err != nil {
		t.Error("didn't expect error", err)
	}
	pool.removeTx(tx.Hash(), true, true)

	// reset the pool's internal state
	resetState()
	if _, err := pool.add(tx); err != nil {
		t.Error("didn't expect error", err)
	}
}

func TestDoubleNonce(t *testing.T) {
	t.Parallel()

	pool, key := setupPool()
	defer pool.Close()

	addr := crypto.PubkeyToAddress(key.PublicKey)
	resetState := func() {
		statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
		statedb.AddBalance(addr, uint256.NewInt(100000000000000), tracing.BalanceChangeUnspecified)

		pool.chain = newTestBlockChain(pool.chainconfig, 1000000, statedb, new(event.Feed))
		<-pool.requestReset(nil, nil)
	}
	resetState()

	signer := types.HomesteadSigner{}
	tx1, _ := types.SignTx(types.NewTransaction(0, common.Address{}, big.NewInt(100), 100000, big.NewInt(1), nil), signer, key)
	tx2, _ := types.SignTx(types.NewTransaction(0, common.Address{}, big.NewInt(100), 1000000, big.NewInt(2), nil), signer, key)
	tx3, _ := types.SignTx(types.NewTransaction(0, common.Address{}, big.NewInt(100), 1000000, big.NewInt(1), nil), signer, key)

	// Add the first two transaction, ensure higher priced stays only
	if replace, err := pool.add(tx1); err != nil || replace {
		t.Errorf("first transaction insert failed (%v) or reported replacement (%v)", err, replace)
	}
	if replace, err := pool.add(tx2); err != nil || !replace {
		t.Errorf("second transaction insert failed (%v) or not reported replacement (%v)", err, replace)
	}
	<-pool.requestPromoteExecutables(newAccountSet(signer, addr))
	if pool.pending[addr].Len() != 1 {
		t.Error("expected 1 pending transactions, got", pool.pending[addr].Len())
	}
	if tx := pool.pending[addr].txs.items[0]; tx.Hash() != tx2.Hash() {
		t.Errorf("transaction mismatch: have %x, want %x", tx.Hash(), tx2.Hash())
	}

	// Add the third transaction and ensure it's not saved (smaller price)
	pool.add(tx3)
	<-pool.requestPromoteExecutables(newAccountSet(signer, addr))
	if pool.pending[addr].Len() != 1 {
		t.Error("expected 1 pending transactions, got", pool.pending[addr].Len())
	}
	if tx := pool.pending[addr].txs.items[0]; tx.Hash() != tx2.Hash() {
		t.Errorf("transaction mismatch: have %x, want %x", tx.Hash(), tx2.Hash())
	}
	// Ensure the total transaction count is correct
	if pool.all.Count() != 1 {
		t.Error("expected 1 total transactions, got", pool.all.Count())
	}
}

func TestMissingNonce(t *testing.T) {
	t.Parallel()

	pool, key := setupPool()
	defer pool.Close()

	addr := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, addr, big.NewInt(100000000000000))
	tx := transaction(1, 100000, key)
	if _, err := pool.add(tx); err != nil {
		t.Error("didn't expect error", err)
	}
	if len(pool.pending) != 0 {
		t.Error("expected 0 pending transactions, got", len(pool.pending))
	}
	if pool.queue[addr].Len() != 1 {
		t.Error("expected 1 queued transaction, got", pool.queue[addr].Len())
	}
	if pool.all.Count() != 1 {
		t.Error("expected 1 total transactions, got", pool.all.Count())
	}
}

func TestNonceRecovery(t *testing.T) {
	t.Parallel()

	const n = 10
	pool, key := setupPool()
	defer pool.Close()

	addr := crypto.PubkeyToAddress(key.PublicKey)
	testSetNonce(pool, addr, n)
	testAddBalance(pool, addr, big.NewInt(100000000000000))
	<-pool.requestReset(nil, nil)

	tx := transaction(n, 100000, key)
	if err := pool.addRemote(tx); err != nil {
		t.Error(err)
	}
	// simulate some weird re-order of transactions and missing nonce(s)
	testSetNonce(pool, addr, n-1)
	<-pool.requestReset(nil, nil)
	if fn := pool.Nonce(addr); fn != n-1 {
		t.Errorf("expected nonce to be %d, got %d", n-1, fn)
	}
}

// Tests that if an account runs out of funds, any pending and queued transactions
// are dropped.
func TestDropping(t *testing.T) {
	t.Parallel()

	// Create a test account and fund it
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000))

	// Add some pending and some queued transactions
	var (
		tx0  = transaction(0, 100, key)
		tx1  = transaction(1, 200, key)
		tx2  = transaction(2, 300, key)
		tx10 = transaction(10, 100, key)
		tx11 = transaction(11, 200, key)
		tx12 = transaction(12, 300, key)
	)
	pool.all.Add(tx0)
	pool.priced.Put(tx0)
	pool.promoteTx(account, tx0.Hash(), tx0)

	pool.all.Add(tx1)
	pool.priced.Put(tx1)
	pool.promoteTx(account, tx1.Hash(), tx1)

	pool.all.Add(tx2)
	pool.priced.Put(tx2)
	pool.promoteTx(account, tx2.Hash(), tx2)

	pool.enqueueTx(tx10.Hash(), tx10, true)
	pool.enqueueTx(tx11.Hash(), tx11, true)
	pool.enqueueTx(tx12.Hash(), tx12, true)

	// Check that pre and post validations leave the pool as is
	if pool.pending[account].Len() != 3 {
		t.Errorf("pending transaction mismatch: have %d, want %d", pool.pending[account].Len(), 3)
	}
	if pool.queue[account].Len() != 3 {
		t.Errorf("queued transaction mismatch: have %d, want %d", pool.queue[account].Len(), 3)
	}
	if pool.all.Count() != 6 {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 6)
	}
	<-pool.requestReset(nil, nil)
	if pool.pending[account].Len() != 3 {
		t.Errorf("pending transaction mismatch: have %d, want %d", pool.pending[account].Len(), 3)
	}
	if pool.queue[account].Len() != 3 {
		t.Errorf("queued transaction mismatch: have %d, want %d", pool.queue[account].Len(), 3)
	}
	if pool.all.Count() != 6 {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 6)
	}
	// Reduce the balance of the account, and check that invalidated transactions are dropped
	testAddBalance(pool, account, big.NewInt(-650))
	<-pool.requestReset(nil, nil)

	if _, ok := pool.pending[account].txs.items[tx0.Nonce()]; !ok {
		t.Errorf("funded pending transaction missing: %v", tx0)
	}
	if _, ok := pool.pending[account].txs.items[tx1.Nonce()]; !ok {
		t.Errorf("funded pending transaction missing: %v", tx0)
	}
	if _, ok := pool.pending[account].txs.items[tx2.Nonce()]; ok {
		t.Errorf("out-of-fund pending transaction present: %v", tx1)
	}
	if _, ok := pool.queue[account].txs.items[tx10.Nonce()]; !ok {
		t.Errorf("funded queued transaction missing: %v", tx10)
	}
	if _, ok := pool.queue[account].txs.items[tx11.Nonce()]; !ok {
		t.Errorf("funded queued transaction missing: %v", tx10)
	}
	if _, ok := pool.queue[account].txs.items[tx12.Nonce()]; ok {
		t.Errorf("out-of-fund queued transaction present: %v", tx11)
	}
	if pool.all.Count() != 4 {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 4)
	}
	// Reduce the block gas limit, check that invalidated transactions are dropped
	pool.chain.(*testBlockChain).gasLimit.Store(100)
	<-pool.requestReset(nil, nil)

	if _, ok := pool.pending[account].txs.items[tx0.Nonce()]; !ok {
		t.Errorf("funded pending transaction missing: %v", tx0)
	}
	if _, ok := pool.pending[account].txs.items[tx1.Nonce()]; ok {
		t.Errorf("over-gased pending transaction present: %v", tx1)
	}
	if _, ok := pool.queue[account].txs.items[tx10.Nonce()]; !ok {
		t.Errorf("funded queued transaction missing: %v", tx10)
	}
	if _, ok := pool.queue[account].txs.items[tx11.Nonce()]; ok {
		t.Errorf("over-gased queued transaction present: %v", tx11)
	}
	if pool.all.Count() != 2 {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 2)
	}
}

// Tests that if a transaction is dropped from the current pending pool (e.g. out
// of fund), all consecutive (still valid, but not executable) transactions are
// postponed back into the future queue to prevent broadcasting them.
func TestPostponing(t *testing.T) {
	t.Parallel()

	// Create the pool to test the postponing with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create two test accounts to produce different gap profiles with
	keys := make([]*ecdsa.PrivateKey, 2)
	accs := make([]common.Address, len(keys))

	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		accs[i] = crypto.PubkeyToAddress(keys[i].PublicKey)

		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(50100))
	}
	// Add a batch consecutive pending transactions for validation
	txs := []*types.Transaction{}
	for i, key := range keys {
		for j := 0; j < 100; j++ {
			var tx *types.Transaction
			if (i+j)%2 == 0 {
				tx = transaction(uint64(j), 25000, key)
			} else {
				tx = transaction(uint64(j), 50000, key)
			}
			txs = append(txs, tx)
		}
	}
	for i, err := range pool.addRemotesSync(txs) {
		if err != nil {
			t.Fatalf("tx %d: failed to add transactions: %v", i, err)
		}
	}
	// Check that pre and post validations leave the pool as is
	if pending := pool.pending[accs[0]].Len() + pool.pending[accs[1]].Len(); pending != len(txs) {
		t.Errorf("pending transaction mismatch: have %d, want %d", pending, len(txs))
	}
	if len(pool.queue) != 0 {
		t.Errorf("queued accounts mismatch: have %d, want %d", len(pool.queue), 0)
	}
	if pool.all.Count() != len(txs) {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), len(txs))
	}
	<-pool.requestReset(nil, nil)
	if pending := pool.pending[accs[0]].Len() + pool.pending[accs[1]].Len(); pending != len(txs) {
		t.Errorf("pending transaction mismatch: have %d, want %d", pending, len(txs))
	}
	if len(pool.queue) != 0 {
		t.Errorf("queued accounts mismatch: have %d, want %d", len(pool.queue), 0)
	}
	if pool.all.Count() != len(txs) {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), len(txs))
	}
	// Reduce the balance of the account, and check that transactions are reorganised
	for _, addr := range accs {
		testAddBalance(pool, addr, big.NewInt(-1))
	}
	<-pool.requestReset(nil, nil)

	// The first account's first transaction remains valid, check that subsequent
	// ones are either filtered out, or queued up for later.
	if _, ok := pool.pending[accs[0]].txs.items[txs[0].Nonce()]; !ok {
		t.Errorf("tx %d: valid and funded transaction missing from pending pool: %v", 0, txs[0])
	}
	if _, ok := pool.queue[accs[0]].txs.items[txs[0].Nonce()]; ok {
		t.Errorf("tx %d: valid and funded transaction present in future queue: %v", 0, txs[0])
	}
	for i, tx := range txs[1:100] {
		if i%2 == 1 {
			if _, ok := pool.pending[accs[0]].txs.items[tx.Nonce()]; ok {
				t.Errorf("tx %d: valid but future transaction present in pending pool: %v", i+1, tx)
			}
			if _, ok := pool.queue[accs[0]].txs.items[tx.Nonce()]; !ok {
				t.Errorf("tx %d: valid but future transaction missing from future queue: %v", i+1, tx)
			}
		} else {
			if _, ok := pool.pending[accs[0]].txs.items[tx.Nonce()]; ok {
				t.Errorf("tx %d: out-of-fund transaction present in pending pool: %v", i+1, tx)
			}
			if _, ok := pool.queue[accs[0]].txs.items[tx.Nonce()]; ok {
				t.Errorf("tx %d: out-of-fund transaction present in future queue: %v", i+1, tx)
			}
		}
	}
	// The second account's first transaction got invalid, check that all transactions
	// are either filtered out, or queued up for later.
	if pool.pending[accs[1]] != nil {
		t.Errorf("invalidated account still has pending transactions")
	}
	for i, tx := range txs[100:] {
		if i%2 == 1 {
			if _, ok := pool.queue[accs[1]].txs.items[tx.Nonce()]; !ok {
				t.Errorf("tx %d: valid but future transaction missing from future queue: %v", 100+i, tx)
			}
		} else {
			if _, ok := pool.queue[accs[1]].txs.items[tx.Nonce()]; ok {
				t.Errorf("tx %d: out-of-fund transaction present in future queue: %v", 100+i, tx)
			}
		}
	}
	if pool.all.Count() != len(txs)/2 {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), len(txs)/2)
	}
}

// Tests that if the transaction pool has both executable and non-executable
// transactions from an origin account, filling the nonce gap moves all queued
// ones into the pending pool.
func TestGapFilling(t *testing.T) {
	t.Parallel()

	// Create a test account and fund it
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000000))

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, testTxPoolConfig.AccountQueue+5)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Create a pending and a queued transaction with a nonce-gap in between
	pool.addRemotesSync([]*types.Transaction{
		transaction(0, 100000, key),
		transaction(2, 100000, key),
	})
	pending, queued := pool.Stats()
	if pending != 1 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 1)
	}
	if queued != 1 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 1)
	}
	if err := validateEvents(events, 1); err != nil {
		t.Fatalf("original event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Fill the nonce gap and ensure all transactions become pending
	if err := pool.addRemoteSync(transaction(1, 100000, key)); err != nil {
		t.Fatalf("failed to add gapped transaction: %v", err)
	}
	pending, queued = pool.Stats()
	if pending != 3 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 3)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validateEvents(events, 2); err != nil {
		t.Fatalf("gap-filling event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that if the transaction count belonging to a single account goes above
// some threshold, the higher transactions are dropped to prevent DOS attacks.
func TestQueueAccountLimiting(t *testing.T) {
	t.Parallel()

	// Create a test account and fund it
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000000))

	// Keep queuing up transactions and make sure all above a limit are dropped
	for i := uint64(1); i <= testTxPoolConfig.AccountQueue+5; i++ {
		if err := pool.addRemoteSync(transaction(i, 100000, key)); err != nil {
			t.Fatalf("tx %d: failed to add transaction: %v", i, err)
		}
		if len(pool.pending) != 0 {
			t.Errorf("tx %d: pending pool size mismatch: have %d, want %d", i, len(pool.pending), 0)
		}
		if i <= testTxPoolConfig.AccountQueue {
			if pool.queue[account].Len() != int(i) {
				t.Errorf("tx %d: queue size mismatch: have %d, want %d", i, pool.queue[account].Len(), i)
			}
		} else {
			if pool.queue[account].Len() != int(testTxPoolConfig.AccountQueue) {
				t.Errorf("tx %d: queue limit mismatch: have %d, want %d", i, pool.queue[account].Len(), testTxPoolConfig.AccountQueue)
			}
		}
	}
	if pool.all.Count() != int(testTxPoolConfig.AccountQueue) {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), testTxPoolConfig.AccountQueue)
	}
}

// Tests that if the transaction count belonging to multiple accounts go above
// some threshold, the higher transactions are dropped to prevent DOS attacks.
//
// This logic should not hold for local transactions, unless the local tracking
// mechanism is disabled.
func TestQueueGlobalLimiting(t *testing.T) {
	t.Parallel()

	// Create the pool to test the limit enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	config := testTxPoolConfig
	config.NoLocals = true
	config.GlobalQueue = config.AccountQueue*3 - 1 // reduce the queue limits to shorten test time (-1 to make it non divisible)

	pool := New(config, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create a number of test accounts and fund them (last one will be the local)
	keys := make([]*ecdsa.PrivateKey, 5)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}

	// Generate and queue a batch of transactions
	nonces := make(map[common.Address]uint64)

	txs := make(types.Transactions, 0, 3*config.GlobalQueue)
	for len(txs) < cap(txs) {
		key := keys[rand.Intn(len(keys)-1)] // skip adding transactions with the local account
		addr := crypto.PubkeyToAddress(key.PublicKey)

		txs = append(txs, transaction(nonces[addr]+1, 100000, key))
		nonces[addr]++
	}
	// Import the batch and verify that limits have been enforced
	pool.addRemotesSync(txs)

	queued := 0
	for addr, list := range pool.queue {
		if list.Len() > int(config.AccountQueue) {
			t.Errorf("addr %x: queued accounts overflown allowance: %d > %d", addr, list.Len(), config.AccountQueue)
		}
		queued += list.Len()
	}
	if queued > int(config.GlobalQueue) {
		t.Fatalf("total transactions overflow allowance: %d > %d", queued, config.GlobalQueue)
	}
}

// Tests that if an account remains idle for a prolonged amount of time, any
// non-executable transactions queued up are dropped to prevent wasting resources
// on shuffling them around.
func TestQueueTimeLimiting(t *testing.T) {
	// Reduce the eviction interval to a testable amount
	defer func(old time.Duration) { evictionInterval = old }(evictionInterval)
	evictionInterval = time.Millisecond * 100

	// Create the pool to test the non-expiration enforcement
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	config := testTxPoolConfig
	config.Lifetime = time.Second

	pool := New(config, blockchain)
	pool.Init(config.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create a test account to ensure remotes expire
	remote, _ := crypto.GenerateKey()

	testAddBalance(pool, crypto.PubkeyToAddress(remote.PublicKey), big.NewInt(1000000000))

	// Add the transaction and ensure it is queued up
	if err := pool.addRemote(pricedTransaction(1, 100000, big.NewInt(1), remote)); err != nil {
		t.Fatalf("failed to add remote transaction: %v", err)
	}
	pending, queued := pool.Stats()
	if pending != 0 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 0)
	}
	if queued != 1 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 2)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}

	// Allow the eviction interval to run
	time.Sleep(2 * evictionInterval)

	// Transactions should not be evicted from the queue yet since lifetime duration has not passed
	pending, queued = pool.Stats()
	if pending != 0 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 0)
	}
	if queued != 1 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 2)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}

	// Wait a bit for eviction to run and clean up any leftovers, and ensure only the local remains
	time.Sleep(2 * config.Lifetime)

	pending, queued = pool.Stats()
	if pending != 0 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 0)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}

	// remove current transactions and increase nonce to prepare for a reset and cleanup
	statedb.SetNonce(crypto.PubkeyToAddress(remote.PublicKey), 2, tracing.NonceChangeUnspecified)
	<-pool.requestReset(nil, nil)

	// make sure queue, pending are cleared
	pending, queued = pool.Stats()
	if pending != 0 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 0)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}

	// Queue gapped transactions
	if err := pool.addRemoteSync(pricedTransaction(4, 100000, big.NewInt(1), remote)); err != nil {
		t.Fatalf("failed to add remote transaction: %v", err)
	}
	time.Sleep(5 * evictionInterval) // A half lifetime pass

	// Queue executable transactions, the life cycle should be restarted.
	if err := pool.addRemoteSync(pricedTransaction(2, 100000, big.NewInt(1), remote)); err != nil {
		t.Fatalf("failed to add remote transaction: %v", err)
	}
	time.Sleep(6 * evictionInterval)

	// All gapped transactions shouldn't be kicked out
	pending, queued = pool.Stats()
	if pending != 1 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 1)
	}
	if queued != 1 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 1)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}

	// The whole life time pass after last promotion, kick out stale transactions
	time.Sleep(2 * config.Lifetime)
	pending, queued = pool.Stats()
	if pending != 1 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 1)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that even if the transaction count belonging to a single account goes
// above some threshold, as long as the transactions are executable, they are
// accepted.
func TestPendingLimiting(t *testing.T) {
	t.Parallel()

	// Create a test account and fund it
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000000000000))

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, testTxPoolConfig.AccountQueue+5)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Keep queuing up transactions and make sure all above a limit are dropped
	for i := uint64(0); i < testTxPoolConfig.AccountQueue+5; i++ {
		if err := pool.addRemoteSync(transaction(i, 100000, key)); err != nil {
			t.Fatalf("tx %d: failed to add transaction: %v", i, err)
		}
		if pool.pending[account].Len() != int(i)+1 {
			t.Errorf("tx %d: pending pool size mismatch: have %d, want %d", i, pool.pending[account].Len(), i+1)
		}
		if len(pool.queue) != 0 {
			t.Errorf("tx %d: queue size mismatch: have %d, want %d", i, pool.queue[account].Len(), 0)
		}
	}
	if pool.all.Count() != int(testTxPoolConfig.AccountQueue+5) {
		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), testTxPoolConfig.AccountQueue+5)
	}
	if err := validateEvents(events, int(testTxPoolConfig.AccountQueue+5)); err != nil {
		t.Fatalf("event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that if the transaction count belonging to multiple accounts go above
// some hard threshold, the higher transactions are dropped to prevent DOS
// attacks.
func TestPendingGlobalLimiting(t *testing.T) {
	t.Parallel()

	// Create the pool to test the limit enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	config := testTxPoolConfig
	config.GlobalSlots = config.AccountSlots * 10

	pool := New(config, blockchain)
	pool.Init(config.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create a number of test accounts and fund them
	keys := make([]*ecdsa.PrivateKey, 5)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}
	// Generate and queue a batch of transactions
	nonces := make(map[common.Address]uint64)

	txs := types.Transactions{}
	for _, key := range keys {
		addr := crypto.PubkeyToAddress(key.PublicKey)
		for j := 0; j < int(config.GlobalSlots)/len(keys)*2; j++ {
			txs = append(txs, transaction(nonces[addr], 100000, key))
			nonces[addr]++
		}
	}
	// Import the batch and verify that limits have been enforced
	pool.addRemotesSync(txs)

	pending := 0
	for _, list := range pool.pending {
		pending += list.Len()
	}
	if pending > int(config.GlobalSlots) {
		t.Fatalf("total pending transactions overflow allowance: %d > %d", pending, config.GlobalSlots)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Test the limit on transaction size is enforced correctly.
// This test verifies every transaction having allowed size
// is added to the pool, and longer transactions are rejected.
func TestAllowedTxSize(t *testing.T) {
	t.Parallel()

	// Create a test account and fund it
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000000000))

	// Find the maximum data length for the kind of transaction which will
	// be generated in the pool.addRemoteSync calls below.
	const largeDataLength = txMaxSize - 200 // enough to have a 5 bytes RLP encoding of the data length number
	txWithLargeData := pricedDataTransaction(0, pool.currentHead.Load().GasLimit, big.NewInt(1), key, largeDataLength)
	maxTxLengthWithoutData := txWithLargeData.Size() - largeDataLength // 103 bytes
	maxTxDataLength := txMaxSize - maxTxLengthWithoutData              // 131072 - 103 = 130969 bytes

	// Try adding a transaction with maximal allowed size
	tx := pricedDataTransaction(0, pool.currentHead.Load().GasLimit, big.NewInt(1), key, maxTxDataLength)
	if err := pool.addRemoteSync(tx); err != nil {
		t.Fatalf("failed to add transaction of size %d, close to maximal: %v", int(tx.Size()), err)
	}
	// Try adding a transaction with random allowed size
	if err := pool.addRemoteSync(pricedDataTransaction(1, pool.currentHead.Load().GasLimit, big.NewInt(1), key, uint64(rand.Intn(int(maxTxDataLength+1))))); err != nil {
		t.Fatalf("failed to add transaction of random allowed size: %v", err)
	}
	// Try adding a transaction above maximum size by one
	if err := pool.addRemoteSync(pricedDataTransaction(2, pool.currentHead.Load().GasLimit, big.NewInt(1), key, maxTxDataLength+1)); err == nil {
		t.Fatalf("expected rejection on slightly oversize transaction")
	}
	// Try adding a transaction above maximum size by more than one
	if err := pool.addRemoteSync(pricedDataTransaction(2, pool.currentHead.Load().GasLimit, big.NewInt(1), key, maxTxDataLength+1+uint64(rand.Intn(10*txMaxSize)))); err == nil {
		t.Fatalf("expected rejection on oversize transaction")
	}
	// Run some sanity checks on the pool internals
	pending, queued := pool.Stats()
	if pending != 2 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 2)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that if transactions start being capped, transactions are also removed from 'all'
func TestCapClearsFromAll(t *testing.T) {
	t.Parallel()

	// Create the pool to test the limit enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	config := testTxPoolConfig
	config.AccountSlots = 2
	config.AccountQueue = 2
	config.GlobalSlots = 8

	pool := New(config, blockchain)
	pool.Init(config.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create a number of test accounts and fund them
	key, _ := crypto.GenerateKey()
	addr := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, addr, big.NewInt(1000000))

	txs := types.Transactions{}
	for j := 0; j < int(config.GlobalSlots)*2; j++ {
		txs = append(txs, transaction(uint64(j), 100000, key))
	}
	// Import the batch and verify that limits have been enforced
	pool.addRemotes(txs)
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that if the transaction count belonging to multiple accounts go above
// some hard threshold, if they are under the minimum guaranteed slot count then
// the transactions are still kept.
func TestPendingMinimumAllowance(t *testing.T) {
	t.Parallel()

	// Create the pool to test the limit enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	config := testTxPoolConfig
	config.GlobalSlots = 1

	pool := New(config, blockchain)
	pool.Init(config.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create a number of test accounts and fund them
	keys := make([]*ecdsa.PrivateKey, 5)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}
	// Generate and queue a batch of transactions
	nonces := make(map[common.Address]uint64)

	txs := types.Transactions{}
	for _, key := range keys {
		addr := crypto.PubkeyToAddress(key.PublicKey)
		for j := 0; j < int(config.AccountSlots)*2; j++ {
			txs = append(txs, transaction(nonces[addr], 100000, key))
			nonces[addr]++
		}
	}
	// Import the batch and verify that limits have been enforced
	pool.addRemotesSync(txs)

	for addr, list := range pool.pending {
		if list.Len() != int(config.AccountSlots) {
			t.Errorf("addr %x: total pending transactions mismatch: have %d, want %d", addr, list.Len(), config.AccountSlots)
		}
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that setting the transaction pool gas price to a higher value correctly
// discards everything cheaper than that and moves any gapped transactions back
// from the pending pool to the queue.
func TestRepricing(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, 32)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Create a number of test accounts and fund them
	keys := make([]*ecdsa.PrivateKey, 3)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}
	// Generate and queue a batch of transactions, both pending and queued
	txs := types.Transactions{}

	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(2), keys[0]))
	txs = append(txs, pricedTransaction(1, 100000, big.NewInt(1), keys[0]))
	txs = append(txs, pricedTransaction(2, 100000, big.NewInt(2), keys[0]))

	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(1), keys[1]))
	txs = append(txs, pricedTransaction(1, 100000, big.NewInt(2), keys[1]))
	txs = append(txs, pricedTransaction(2, 100000, big.NewInt(2), keys[1]))

	txs = append(txs, pricedTransaction(1, 100000, big.NewInt(2), keys[2]))
	txs = append(txs, pricedTransaction(2, 100000, big.NewInt(1), keys[2]))
	txs = append(txs, pricedTransaction(3, 100000, big.NewInt(2), keys[2]))

	// Import the batch and that both pending and queued transactions match up
	pool.addRemotesSync(txs)

	pending, queued := pool.Stats()
	if pending != 6 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 6)
	}
	if queued != 3 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 3)
	}
	if err := validateEvents(events, 6); err != nil {
		t.Fatalf("original event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Reprice the pool and check that underpriced transactions get dropped
	pool.SetGasTip(big.NewInt(2))

	pending, queued = pool.Stats()
	if pending != 1 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 1)
	}
	if queued != 5 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 5)
	}
	if err := validateEvents(events, 0); err != nil {
		t.Fatalf("reprice event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Check that we can't add the old transactions back
	if err := pool.addRemote(pricedTransaction(1, 100000, big.NewInt(1), keys[0])); !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("adding underpriced pending transaction error mismatch: have %v, want %v", err, txpool.ErrTxGasPriceTooLow)
	}
	if err := pool.addRemote(pricedTransaction(0, 100000, big.NewInt(1), keys[1])); !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("adding underpriced pending transaction error mismatch: have %v, want %v", err, txpool.ErrTxGasPriceTooLow)
	}
	if err := pool.addRemote(pricedTransaction(2, 100000, big.NewInt(1), keys[2])); !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("adding underpriced queued transaction error mismatch: have %v, want %v", err, txpool.ErrTxGasPriceTooLow)
	}
	if err := validateEvents(events, 0); err != nil {
		t.Fatalf("post-reprice event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// we can fill gaps with properly priced transactions
	if err := pool.addRemote(pricedTransaction(1, 100000, big.NewInt(2), keys[0])); err != nil {
		t.Fatalf("failed to add pending transaction: %v", err)
	}
	if err := pool.addRemote(pricedTransaction(0, 100000, big.NewInt(2), keys[1])); err != nil {
		t.Fatalf("failed to add pending transaction: %v", err)
	}
	if err := pool.addRemoteSync(pricedTransaction(2, 100000, big.NewInt(2), keys[2])); err != nil {
		t.Fatalf("failed to add queued transaction: %v", err)
	}
	if err := validateEvents(events, 5); err != nil {
		t.Fatalf("post-reprice event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

func TestMinGasPriceEnforced(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(eip1559Config, 10000000, statedb, new(event.Feed))

	txPoolConfig := DefaultConfig
	txPoolConfig.NoLocals = true
	pool := New(txPoolConfig, blockchain)
	pool.Init(txPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	key, _ := crypto.GenerateKey()
	testAddBalance(pool, crypto.PubkeyToAddress(key.PublicKey), big.NewInt(1000000))

	tx := pricedTransaction(0, 100000, big.NewInt(2), key)
	pool.SetGasTip(big.NewInt(tx.GasPrice().Int64() + 1))

	if err := pool.Add([]*types.Transaction{tx}, true)[0]; !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("Min tip not enforced")
	}

	tx = dynamicFeeTx(0, 100000, big.NewInt(3), big.NewInt(2), key)
	pool.SetGasTip(big.NewInt(tx.GasTipCap().Int64() + 1))

	if err := pool.Add([]*types.Transaction{tx}, true)[0]; !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("Min tip not enforced")
	}
}

// Tests that setting the transaction pool gas price to a higher value correctly
// discards everything cheaper (legacy & dynamic fee) than that and moves any
// gapped transactions back from the pending pool to the queue.
//
// Note, local transactions are never allowed to be dropped.
func TestRepricingDynamicFee(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	pool, _ := setupPoolWithConfig(eip1559Config)
	defer pool.Close()

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, 32)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Create a number of test accounts and fund them
	keys := make([]*ecdsa.PrivateKey, 4)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}
	// Generate and queue a batch of transactions, both pending and queued
	txs := types.Transactions{}

	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(2), keys[0]))
	txs = append(txs, pricedTransaction(1, 100000, big.NewInt(1), keys[0]))
	txs = append(txs, pricedTransaction(2, 100000, big.NewInt(2), keys[0]))

	txs = append(txs, dynamicFeeTx(0, 100000, big.NewInt(2), big.NewInt(1), keys[1]))
	txs = append(txs, dynamicFeeTx(1, 100000, big.NewInt(3), big.NewInt(2), keys[1]))
	txs = append(txs, dynamicFeeTx(2, 100000, big.NewInt(3), big.NewInt(2), keys[1]))

	txs = append(txs, dynamicFeeTx(1, 100000, big.NewInt(2), big.NewInt(2), keys[2]))
	txs = append(txs, dynamicFeeTx(2, 100000, big.NewInt(1), big.NewInt(1), keys[2]))
	txs = append(txs, dynamicFeeTx(3, 100000, big.NewInt(2), big.NewInt(2), keys[2]))

	// Import the batch and that both pending and queued transactions match up
	pool.addRemotesSync(txs)

	pending, queued := pool.Stats()
	if pending != 6 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 6)
	}
	if queued != 3 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 3)
	}
	if err := validateEvents(events, 6); err != nil {
		t.Fatalf("original event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Reprice the pool and check that underpriced transactions get dropped
	pool.SetGasTip(big.NewInt(2))

	pending, queued = pool.Stats()
	if pending != 1 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 1)
	}
	if queued != 5 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 5)
	}
	if err := validateEvents(events, 0); err != nil {
		t.Fatalf("reprice event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Check that we can't add the old transactions back
	tx := pricedTransaction(1, 100000, big.NewInt(1), keys[0])
	if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("adding underpriced pending transaction error mismatch: have %v, want %v", err, txpool.ErrTxGasPriceTooLow)
	}
	tx = dynamicFeeTx(0, 100000, big.NewInt(2), big.NewInt(1), keys[1])
	if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("adding underpriced pending transaction error mismatch: have %v, want %v", err, txpool.ErrTxGasPriceTooLow)
	}
	tx = dynamicFeeTx(2, 100000, big.NewInt(1), big.NewInt(1), keys[2])
	if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrTxGasPriceTooLow) {
		t.Fatalf("adding underpriced queued transaction error mismatch: have %v, want %v", err, txpool.ErrTxGasPriceTooLow)
	}
	if err := validateEvents(events, 0); err != nil {
		t.Fatalf("post-reprice event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}

	// And we can fill gaps with properly priced transactions
	tx = pricedTransaction(1, 100000, big.NewInt(2), keys[0])
	if err := pool.addRemote(tx); err != nil {
		t.Fatalf("failed to add pending transaction: %v", err)
	}
	tx = dynamicFeeTx(0, 100000, big.NewInt(3), big.NewInt(2), keys[1])
	if err := pool.addRemote(tx); err != nil {
		t.Fatalf("failed to add pending transaction: %v", err)
	}
	tx = dynamicFeeTx(2, 100000, big.NewInt(2), big.NewInt(2), keys[2])
	if err := pool.addRemoteSync(tx); err != nil {
		t.Fatalf("failed to add queued transaction: %v", err)
	}
	if err := validateEvents(events, 5); err != nil {
		t.Fatalf("post-reprice event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that when the pool reaches its global transaction limit, underpriced
// transactions are gradually shifted out for more expensive ones and any gapped
// pending transactions are moved into the queue.
//
// Note, local transactions are never allowed to be dropped.
func TestUnderpricing(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	config := testTxPoolConfig
	config.GlobalSlots = 2
	config.GlobalQueue = 2

	pool := New(config, blockchain)
	pool.Init(config.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, 32)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Create a number of test accounts and fund them
	keys := make([]*ecdsa.PrivateKey, 5)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(10000000))
	}
	// Generate and queue a batch of transactions, both pending and queued
	txs := types.Transactions{}

	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(1), keys[0])) // pending
	txs = append(txs, pricedTransaction(1, 100000, big.NewInt(2), keys[0])) // pending
	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(1), keys[2])) // pending

	txs = append(txs, pricedTransaction(1, 100000, big.NewInt(1), keys[1])) // queued
	// Import the batch and that both pending and queued transactions match up
	pool.addRemotesSync(txs)

	pending, queued := pool.Stats()
	if pending != 3 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 3)
	}
	if queued != 1 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 1)
	}
	if err := validateEvents(events, 3); err != nil {
		t.Fatalf("original event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Ensure that adding an underpriced transaction on block limit fails
	if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1), keys[1])); !errors.Is(err, txpool.ErrUnderpriced) {
		t.Fatalf("adding underpriced pending transaction error mismatch: have %v, want %v", err, txpool.ErrUnderpriced)
	}
	// Replace a future transaction with a future transaction
	if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(5), keys[1])); err != nil { // +K1:1 => -K1:1 => Pend K0:0, K0:1, K2:0; Que K1:1
		t.Fatalf("failed to add well priced transaction: %v", err)
	}
	// Ensure that adding high priced transactions drops cheap ones, but not own
	if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(3), keys[1])); err != nil { // +K1:0 => -K1:1 => Pend K0:0, K0:1, K1:0, K2:0; Que -
		t.Fatalf("failed to add well priced transaction: %v", err)
	}
	if err := pool.addRemoteSync(pricedTransaction(2, 100000, big.NewInt(4), keys[1])); err != nil { // +K1:2 => -K0:0 => Pend K1:0, K2:0; Que K0:1 K1:2
		t.Fatalf("failed to add well priced transaction: %v", err)
	}
	if err := pool.addRemoteSync(pricedTransaction(3, 100000, big.NewInt(5), keys[1])); err != nil { // +K1:3 => -K0:1 => Pend K1:0, K2:0; Que K1:2 K1:3
		t.Fatalf("failed to add well priced transaction: %v", err)
	}
	// Ensure that replacing a pending transaction with a future transaction fails
	if err := pool.addRemoteSync(pricedTransaction(5, 100000, big.NewInt(6), keys[1])); !errors.Is(err, ErrFutureReplacePending) {
		t.Fatalf("adding future replace transaction error mismatch: have %v, want %v", err, ErrFutureReplacePending)
	}
	pending, queued = pool.Stats()
	if pending != 4 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 4)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validateEvents(events, 4); err != nil {
		t.Fatalf("additional event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that more expensive transactions push out cheap ones from the pool, but
// without producing instability by creating gaps that start jumping transactions
// back and forth between queued/pending.
func TestStableUnderpricing(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	config := testTxPoolConfig
	config.GlobalSlots = 128
	config.GlobalQueue = 0

	pool := New(config, blockchain)
	pool.Init(config.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, 32)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Create a number of test accounts and fund them
	keys := make([]*ecdsa.PrivateKey, 2)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}
	// Fill up the entire queue with the same transaction price points
	txs := types.Transactions{}
	for i := uint64(0); i < config.GlobalSlots; i++ {
		txs = append(txs, pricedTransaction(i, 100000, big.NewInt(1), keys[0]))
	}
	pool.addRemotesSync(txs)

	pending, queued := pool.Stats()
	if pending != int(config.GlobalSlots) {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, config.GlobalSlots)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validateEvents(events, int(config.GlobalSlots)); err != nil {
		t.Fatalf("original event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Ensure that adding high priced transactions drops a cheap, but doesn't produce a gap
	if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(3), keys[1])); err != nil {
		t.Fatalf("failed to add well priced transaction: %v", err)
	}
	pending, queued = pool.Stats()
	if pending != int(config.GlobalSlots) {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, config.GlobalSlots)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validateEvents(events, 1); err != nil {
		t.Fatalf("additional event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that when the pool reaches its global transaction limit, underpriced
// transactions (legacy & dynamic fee) are gradually shifted out for more
// expensive ones and any gapped pending transactions are moved into the queue.
func TestUnderpricingDynamicFee(t *testing.T) {
	t.Parallel()

	pool, _ := setupPoolWithConfig(eip1559Config)
	defer pool.Close()

	pool.config.GlobalSlots = 2
	pool.config.GlobalQueue = 2

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, 32)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Create a number of test accounts and fund them
	keys := make([]*ecdsa.PrivateKey, 4)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}

	// Generate and queue a batch of transactions, both pending and queued
	txs := types.Transactions{}

	txs = append(txs, dynamicFeeTx(0, 100000, big.NewInt(3), big.NewInt(2), keys[0])) // pending
	txs = append(txs, pricedTransaction(1, 100000, big.NewInt(2), keys[0]))           // pending
	txs = append(txs, dynamicFeeTx(1, 100000, big.NewInt(2), big.NewInt(1), keys[1])) // queued
	txs = append(txs, dynamicFeeTx(0, 100000, big.NewInt(2), big.NewInt(1), keys[2])) // pending

	// Import the batch and check that both pending and queued transactions match up
	pool.addRemotesSync(txs) // Pend K0:0, K0:1; Que K1:1

	pending, queued := pool.Stats()
	if pending != 3 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 3)
	}
	if queued != 1 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 1)
	}
	if err := validateEvents(events, 3); err != nil {
		t.Fatalf("original event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}

	// Ensure that adding an underpriced transaction fails
	tx := dynamicFeeTx(0, 100000, big.NewInt(2), big.NewInt(1), keys[1])
	if err := pool.addRemoteSync(tx); !errors.Is(err, txpool.ErrUnderpriced) { // Pend K0:0, K0:1, K2:0; Que K1:1
		t.Fatalf("adding underpriced pending transaction error mismatch: have %v, want %v", err, txpool.ErrUnderpriced)
	}

	// Ensure that adding high priced transactions drops cheap ones, but not own
	tx = pricedTransaction(0, 100000, big.NewInt(2), keys[1])
	if err := pool.addRemoteSync(tx); err != nil { // +K1:0, -K1:1 => Pend K0:0, K0:1, K1:0, K2:0; Que -
		t.Fatalf("failed to add well priced transaction: %v", err)
	}

	tx = pricedTransaction(1, 100000, big.NewInt(3), keys[1])
	if err := pool.addRemoteSync(tx); err != nil { // +K1:2, -K0:1 => Pend K0:0 K1:0, K2:0; Que K1:2
		t.Fatalf("failed to add well priced transaction: %v", err)
	}
	tx = dynamicFeeTx(2, 100000, big.NewInt(4), big.NewInt(1), keys[1])
	if err := pool.addRemoteSync(tx); err != nil { // +K1:3, -K1:0 => Pend K0:0 K2:0; Que K1:2 K1:3
		t.Fatalf("failed to add well priced transaction: %v", err)
	}
	pending, queued = pool.Stats()
	if pending != 4 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 4)
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validateEvents(events, 3); err != nil {
		t.Fatalf("additional event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests whether highest fee cap transaction is retained after a batch of high effective
// tip transactions are added and vice versa
func TestDualHeapEviction(t *testing.T) {
	t.Parallel()

	pool, _ := setupPoolWithConfig(eip1559Config)
	defer pool.Close()

	pool.config.GlobalSlots = 10
	pool.config.GlobalQueue = 10

	var (
		highTip, highCap *types.Transaction
		baseFee          int
	)

	check := func(tx *types.Transaction, name string) {
		if pool.all.Get(tx.Hash()) == nil {
			t.Fatalf("highest %s transaction evicted from the pool", name)
		}
	}

	add := func(urgent bool) {
		for i := 0; i < 20; i++ {
			var tx *types.Transaction
			// Create a test accounts and fund it
			key, _ := crypto.GenerateKey()
			testAddBalance(pool, crypto.PubkeyToAddress(key.PublicKey), big.NewInt(1000000000000))
			if urgent {
				tx = dynamicFeeTx(0, 100000, big.NewInt(int64(baseFee+1+i)), big.NewInt(int64(1+i)), key)
				highTip = tx
			} else {
				tx = dynamicFeeTx(0, 100000, big.NewInt(int64(baseFee+200+i)), big.NewInt(1), key)
				highCap = tx
			}
			pool.addRemotesSync([]*types.Transaction{tx})
		}
		pending, queued := pool.Stats()
		if pending+queued != 20 {
			t.Fatalf("transaction count mismatch: have %d, want %d", pending+queued, 10)
		}
	}

	add(false)
	for baseFee = 0; baseFee <= 1000; baseFee += 100 {
		pool.priced.SetBaseFee(big.NewInt(int64(baseFee)))
		add(true)
		check(highCap, "fee cap")
		add(false)
		check(highTip, "effective tip")
	}

	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that the pool rejects duplicate transactions.
func TestDeduplication(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create a test account to add transactions with
	key, _ := crypto.GenerateKey()
	testAddBalance(pool, crypto.PubkeyToAddress(key.PublicKey), big.NewInt(1000000000))

	// Create a batch of transactions and add a few of them
	txs := make([]*types.Transaction, 16)
	for i := 0; i < len(txs); i++ {
		txs[i] = pricedTransaction(uint64(i), 100000, big.NewInt(1), key)
	}
	var firsts []*types.Transaction
	for i := 0; i < len(txs); i += 2 {
		firsts = append(firsts, txs[i])
	}
	errs := pool.addRemotesSync(firsts)
	if len(errs) != len(firsts) {
		t.Fatalf("first add mismatching result count: have %d, want %d", len(errs), len(firsts))
	}
	for i, err := range errs {
		if err != nil {
			t.Errorf("add %d failed: %v", i, err)
		}
	}
	pending, queued := pool.Stats()
	if pending != 1 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 1)
	}
	if queued != len(txs)/2-1 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, len(txs)/2-1)
	}
	// Try to add all of them now and ensure previous ones error out as knowns
	errs = pool.addRemotesSync(txs)
	if len(errs) != len(txs) {
		t.Fatalf("all add mismatching result count: have %d, want %d", len(errs), len(txs))
	}
	for i, err := range errs {
		if i%2 == 0 && err == nil {
			t.Errorf("add %d succeeded, should have failed as known", i)
		}
		if i%2 == 1 && err != nil {
			t.Errorf("add %d failed: %v", i, err)
		}
	}
	pending, queued = pool.Stats()
	if pending != len(txs) {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, len(txs))
	}
	if queued != 0 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that the pool rejects replacement transactions that don't meet the minimum
// price bump required.
func TestReplacement(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, 32)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Create a test account to add transactions with
	key, _ := crypto.GenerateKey()
	testAddBalance(pool, crypto.PubkeyToAddress(key.PublicKey), big.NewInt(1000000000))

	// Add pending transactions, ensuring the minimum price bump is enforced for replacement (for ultra low prices too)
	price := int64(100)
	threshold := (price * (100 + int64(testTxPoolConfig.PriceBump))) / 100

	if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1), key)); err != nil {
		t.Fatalf("failed to add original cheap pending transaction: %v", err)
	}
	if err := pool.addRemote(pricedTransaction(0, 100001, big.NewInt(1), key)); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
		t.Fatalf("original cheap pending transaction replacement error mismatch: have %v, want %v", err, txpool.ErrReplaceUnderpriced)
	}
	if err := pool.addRemote(pricedTransaction(0, 100000, big.NewInt(2), key)); err != nil {
		t.Fatalf("failed to replace original cheap pending transaction: %v", err)
	}
	if err := validateEvents(events, 2); err != nil {
		t.Fatalf("cheap replacement event firing failed: %v", err)
	}

	if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(price), key)); err != nil {
		t.Fatalf("failed to add original proper pending transaction: %v", err)
	}
	if err := pool.addRemote(pricedTransaction(0, 100001, big.NewInt(threshold-1), key)); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
		t.Fatalf("original proper pending transaction replacement error mismatch: have %v, want %v", err, txpool.ErrReplaceUnderpriced)
	}
	if err := pool.addRemote(pricedTransaction(0, 100000, big.NewInt(threshold), key)); err != nil {
		t.Fatalf("failed to replace original proper pending transaction: %v", err)
	}
	if err := validateEvents(events, 2); err != nil {
		t.Fatalf("proper replacement event firing failed: %v", err)
	}

	// Add queued transactions, ensuring the minimum price bump is enforced for replacement (for ultra low prices too)
	if err := pool.addRemote(pricedTransaction(2, 100000, big.NewInt(1), key)); err != nil {
		t.Fatalf("failed to add original cheap queued transaction: %v", err)
	}
	if err := pool.addRemote(pricedTransaction(2, 100001, big.NewInt(1), key)); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
		t.Fatalf("original cheap queued transaction replacement error mismatch: have %v, want %v", err, txpool.ErrReplaceUnderpriced)
	}
	if err := pool.addRemote(pricedTransaction(2, 100000, big.NewInt(2), key)); err != nil {
		t.Fatalf("failed to replace original cheap queued transaction: %v", err)
	}

	if err := pool.addRemote(pricedTransaction(2, 100000, big.NewInt(price), key)); err != nil {
		t.Fatalf("failed to add original proper queued transaction: %v", err)
	}
	if err := pool.addRemote(pricedTransaction(2, 100001, big.NewInt(threshold-1), key)); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
		t.Fatalf("original proper queued transaction replacement error mismatch: have %v, want %v", err, txpool.ErrReplaceUnderpriced)
	}
	if err := pool.addRemote(pricedTransaction(2, 100000, big.NewInt(threshold), key)); err != nil {
		t.Fatalf("failed to replace original proper queued transaction: %v", err)
	}

	if err := validateEvents(events, 0); err != nil {
		t.Fatalf("queued replacement event firing failed: %v", err)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// Tests that the pool rejects replacement dynamic fee transactions that don't
// meet the minimum price bump required.
func TestReplacementDynamicFee(t *testing.T) {
	t.Parallel()

	// Create the pool to test the pricing enforcement with
	pool, key := setupPoolWithConfig(eip1559Config)
	defer pool.Close()
	testAddBalance(pool, crypto.PubkeyToAddress(key.PublicKey), big.NewInt(1000000000))

	// Keep track of transaction events to ensure all executables get announced
	events := make(chan core.NewTxsEvent, 32)
	sub := pool.txFeed.Subscribe(events)
	defer sub.Unsubscribe()

	// Add pending transactions, ensuring the minimum price bump is enforced for replacement (for ultra low prices too)
	gasFeeCap := int64(100)
	feeCapThreshold := (gasFeeCap * (100 + int64(testTxPoolConfig.PriceBump))) / 100
	gasTipCap := int64(60)
	tipThreshold := (gasTipCap * (100 + int64(testTxPoolConfig.PriceBump))) / 100

	// Run the following identical checks for both the pending and queue pools:
	//	1.  Send initial tx => accept
	//	2.  Don't bump tip or fee cap => discard
	//	3.  Bump both more than min => accept
	//	4.  Check events match expected (2 new executable txs during pending, 0 during queue)
	//	5.  Send new tx with larger tip and gasFeeCap => accept
	//	6.  Bump tip max allowed so it's still underpriced => discard
	//	7.  Bump fee cap max allowed so it's still underpriced => discard
	//	8.  Bump tip min for acceptance => discard
	//	9.  Bump feecap min for acceptance => discard
	//	10. Bump feecap and tip min for acceptance => accept
	//	11. Check events match expected (2 new executable txs during pending, 0 during queue)
	stages := []string{"pending", "queued"}
	for _, stage := range stages {
		// Since state is empty, 0 nonce txs are "executable" and can go
		// into pending immediately. 2 nonce txs are "gapped"
		nonce := uint64(0)
		if stage == "queued" {
			nonce = 2
		}

		// 1.  Send initial tx => accept
		tx := dynamicFeeTx(nonce, 100000, big.NewInt(2), big.NewInt(1), key)
		if err := pool.addRemoteSync(tx); err != nil {
			t.Fatalf("failed to add original cheap %s transaction: %v", stage, err)
		}
		// 2.  Don't bump tip or feecap => discard
		tx = dynamicFeeTx(nonce, 100001, big.NewInt(2), big.NewInt(1), key)
		if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
			t.Fatalf("original cheap %s transaction replacement error mismatch: have %v, want %v", stage, err, txpool.ErrReplaceUnderpriced)
		}
		// 3.  Bump both more than min => accept
		tx = dynamicFeeTx(nonce, 100000, big.NewInt(3), big.NewInt(2), key)
		if err := pool.addRemote(tx); err != nil {
			t.Fatalf("failed to replace original cheap %s transaction: %v", stage, err)
		}
		// 4.  Check events match expected (2 new executable txs during pending, 0 during queue)
		count := 2
		if stage == "queued" {
			count = 0
		}
		if err := validateEvents(events, count); err != nil {
			t.Fatalf("cheap %s replacement event firing failed: %v", stage, err)
		}
		// 5.  Send new tx with larger tip and feeCap => accept
		tx = dynamicFeeTx(nonce, 100000, big.NewInt(gasFeeCap), big.NewInt(gasTipCap), key)
		if err := pool.addRemoteSync(tx); err != nil {
			t.Fatalf("failed to add original proper %s transaction: %v", stage, err)
		}

		// 6.  Bump tip max allowed so it's still underpriced => discard
		tx = dynamicFeeTx(nonce, 100000, big.NewInt(gasFeeCap), big.NewInt(tipThreshold-1), key)
		if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
			t.Fatalf("original proper %s transaction replacement error mismatch: have %v, want %v", stage, err, txpool.ErrReplaceUnderpriced)
		}
		// 7.  Bump fee cap max allowed so it's still underpriced => discard
		tx = dynamicFeeTx(nonce, 100000, big.NewInt(feeCapThreshold-1), big.NewInt(gasTipCap), key)
		if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
			t.Fatalf("original proper %s transaction replacement error mismatch: have %v, want %v", stage, err, txpool.ErrReplaceUnderpriced)
		}
		// 8.  Bump tip min for acceptance => accept
		tx = dynamicFeeTx(nonce, 100000, big.NewInt(gasFeeCap), big.NewInt(tipThreshold), key)
		if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
			t.Fatalf("original proper %s transaction replacement error mismatch: have %v, want %v", stage, err, txpool.ErrReplaceUnderpriced)
		}
		// 9.  Bump fee cap min for acceptance => accept
		tx = dynamicFeeTx(nonce, 100000, big.NewInt(feeCapThreshold), big.NewInt(gasTipCap), key)
		if err := pool.addRemote(tx); !errors.Is(err, txpool.ErrReplaceUnderpriced) {
			t.Fatalf("original proper %s transaction replacement error mismatch: have %v, want %v", stage, err, txpool.ErrReplaceUnderpriced)
		}
		// 10. Check events match expected (3 new executable txs during pending, 0 during queue)
		tx = dynamicFeeTx(nonce, 100000, big.NewInt(feeCapThreshold), big.NewInt(tipThreshold), key)
		if err := pool.addRemote(tx); err != nil {
			t.Fatalf("failed to replace original cheap %s transaction: %v", stage, err)
		}
		// 11. Check events match expected (3 new executable txs during pending, 0 during queue)
		count = 2
		if stage == "queued" {
			count = 0
		}
		if err := validateEvents(events, count); err != nil {
			t.Fatalf("replacement %s event firing failed: %v", stage, err)
		}
	}

	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
}

// TestStatusCheck tests that the pool can correctly retrieve the
// pending status of individual transactions.
func TestStatusCheck(t *testing.T) {
	t.Parallel()

	// Create the pool to test the status retrievals with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.TestChainConfig, 1000000, statedb, new(event.Feed))

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create the test accounts to check various transaction statuses with
	keys := make([]*ecdsa.PrivateKey, 3)
	for i := 0; i < len(keys); i++ {
		keys[i], _ = crypto.GenerateKey()
		testAddBalance(pool, crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
	}
	// Generate and queue a batch of transactions, both pending and queued
	txs := types.Transactions{}

	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(1), keys[0])) // Pending only
	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(1), keys[1])) // Pending and queued
	txs = append(txs, pricedTransaction(2, 100000, big.NewInt(1), keys[1]))
	txs = append(txs, pricedTransaction(2, 100000, big.NewInt(1), keys[2])) // Queued only

	// Import the transaction and ensure they are correctly added
	pool.addRemotesSync(txs)

	pending, queued := pool.Stats()
	if pending != 2 {
		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 2)
	}
	if queued != 2 {
		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 2)
	}
	if err := validatePoolInternals(pool); err != nil {
		t.Fatalf("pool internal state corrupted: %v", err)
	}
	// Retrieve the status of each transaction and validate them
	hashes := make([]common.Hash, len(txs))
	for i, tx := range txs {
		hashes[i] = tx.Hash()
	}
	hashes = append(hashes, common.Hash{})
	expect := []txpool.TxStatus{txpool.TxStatusPending, txpool.TxStatusPending, txpool.TxStatusQueued, txpool.TxStatusQueued, txpool.TxStatusUnknown}

	for i := 0; i < len(hashes); i++ {
		if status := pool.Status(hashes[i]); status != expect[i] {
			t.Errorf("transaction %d: status mismatch: have %v, want %v", i, status, expect[i])
		}
	}
}

// Test the transaction slots consumption is computed correctly
func TestSlotCount(t *testing.T) {
	t.Parallel()

	key, _ := crypto.GenerateKey()

	// Check that an empty transaction consumes a single slot
	smallTx := pricedDataTransaction(0, 0, big.NewInt(0), key, 0)
	if slots := numSlots(smallTx); slots != 1 {
		t.Fatalf("small transactions slot count mismatch: have %d want %d", slots, 1)
	}
	// Check that a large transaction consumes the correct number of slots
	bigTx := pricedDataTransaction(0, 0, big.NewInt(0), key, uint64(10*txSlotSize))
	if slots := numSlots(bigTx); slots != 11 {
		t.Fatalf("big transactions slot count mismatch: have %d want %d", slots, 11)
	}
}

// TestSetCodeTransactions tests a few scenarios regarding the EIP-7702
// SetCodeTx.
func TestSetCodeTransactions(t *testing.T) {
	t.Parallel()

	// Create the pool to test the status retrievals with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.MergedTestChainConfig, 1000000, statedb, new(event.Feed))

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create the test accounts
	var (
		keyA, _ = crypto.GenerateKey()
		keyB, _ = crypto.GenerateKey()
		keyC, _ = crypto.GenerateKey()
		addrA   = crypto.PubkeyToAddress(keyA.PublicKey)
		addrB   = crypto.PubkeyToAddress(keyB.PublicKey)
		addrC   = crypto.PubkeyToAddress(keyC.PublicKey)
	)
	testAddBalance(pool, addrA, big.NewInt(params.Ether))
	testAddBalance(pool, addrB, big.NewInt(params.Ether))
	testAddBalance(pool, addrC, big.NewInt(params.Ether))

	for _, tt := range []struct {
		name    string
		pending int
		queued  int
		run     func(string)
	}{
		{
			// Check that only one in-flight transaction is allowed for accounts
			// with delegation set.
			name:    "accept-one-inflight-tx-of-delegated-account",
			pending: 1,
			run: func(name string) {
				aa := common.Address{0xaa, 0xaa}
				statedb.SetCode(addrA, append(types.DelegationPrefix, aa.Bytes()...))
				statedb.SetCode(aa, []byte{byte(vm.ADDRESS), byte(vm.PUSH0), byte(vm.SSTORE)})

				// Send gapped transaction, it should be rejected.
				if err := pool.addRemoteSync(pricedTransaction(2, 100000, big.NewInt(1), keyA)); !errors.Is(err, ErrOutOfOrderTxFromDelegated) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, ErrOutOfOrderTxFromDelegated, err)
				}
				// Send transactions. First is accepted, second is rejected.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1), keyA)); err != nil {
					t.Fatalf("%s: failed to add remote transaction: %v", name, err)
				}
				// Second and further transactions shall be rejected
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1), keyA)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, txpool.ErrInflightTxLimitReached, err)
				}
				// Check gapped transaction again.
				if err := pool.addRemoteSync(pricedTransaction(2, 100000, big.NewInt(1), keyA)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, txpool.ErrInflightTxLimitReached, err)
				}
				// Replace by fee.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(10), keyA)); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}

				// Reset the delegation, avoid leaking state into the other tests
				statedb.SetCode(addrA, nil)
			},
		},
		{
			// This test is analogous to the previous one, but the delegation is pending
			// instead of set.
			name:    "allow-one-tx-from-pooled-delegation",
			pending: 2,
			run: func(name string) {
				// Create a pending delegation request from B.
				if err := pool.addRemoteSync(setCodeTx(0, keyA, []unsignedAuth{{0, keyB}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				// First transaction from B is accepted.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1), keyB)); err != nil {
					t.Fatalf("%s: failed to add remote transaction: %v", name, err)
				}
				// Second transaction fails due to limit.
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1), keyB)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, txpool.ErrInflightTxLimitReached, err)
				}
				// Replace by fee for first transaction from B works.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(2), keyB)); err != nil {
					t.Fatalf("%s: failed to add remote transaction: %v", name, err)
				}
			},
		},
		{
			// This is the symmetric case of the previous one, where the delegation request
			// is received after the transaction. The resulting state shall be the same.
			name:    "accept-authorization-from-sender-of-one-inflight-tx",
			pending: 2,
			run: func(name string) {
				// The first in-flight transaction is accepted.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1), keyB)); err != nil {
					t.Fatalf("%s: failed to add with pending delegation: %v", name, err)
				}
				// Delegation is accepted.
				if err := pool.addRemoteSync(setCodeTx(0, keyA, []unsignedAuth{{0, keyB}})); err != nil {
					t.Fatalf("%s: failed to add remote transaction: %v", name, err)
				}
				// The second in-flight transaction is rejected.
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1), keyB)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, txpool.ErrInflightTxLimitReached, err)
				}
			},
		},
		{
			name:    "reject-authorization-from-sender-with-more-than-one-inflight-tx",
			pending: 2,
			run: func(name string) {
				// Submit two transactions.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1), keyB)); err != nil {
					t.Fatalf("%s: failed to add with pending delegation: %v", name, err)
				}
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1), keyB)); err != nil {
					t.Fatalf("%s: failed to add with pending delegation: %v", name, err)
				}
				// Delegation rejected since two txs are already in-flight.
				if err := pool.addRemoteSync(setCodeTx(0, keyA, []unsignedAuth{{0, keyB}})); !errors.Is(err, ErrAuthorityReserved) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, ErrAuthorityReserved, err)
				}
			},
		},
		{
			name:    "allow-setcode-tx-with-pending-authority-tx",
			pending: 2,
			run: func(name string) {
				// Send two transactions where the first has no conflicting delegations and
				// the second should be allowed despite conflicting with the authorities in the first.
				if err := pool.addRemoteSync(setCodeTx(0, keyA, []unsignedAuth{{1, keyC}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				if err := pool.addRemoteSync(setCodeTx(0, keyB, []unsignedAuth{{1, keyC}})); err != nil {
					t.Fatalf("%s: failed to add conflicting delegation: %v", name, err)
				}
			},
		},
		{
			name:    "replace-by-fee-setcode-tx",
			pending: 1,
			run: func(name string) {
				if err := pool.addRemoteSync(setCodeTx(0, keyB, []unsignedAuth{{1, keyC}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(2000), uint256.NewInt(2), keyB, []unsignedAuth{{0, keyC}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
			},
		},
		{
			name:    "allow-more-than-one-tx-from-replaced-authority",
			pending: 3,
			run: func(name string) {
				// Send transaction from A with B as an authority.
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(10), uint256.NewInt(3), keyA, []unsignedAuth{{0, keyB}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				// Replace transaction with another having C as an authority.
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(3000), uint256.NewInt(300), keyA, []unsignedAuth{{0, keyC}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				// B should not be considred as having an in-flight delegation, so
				// should allow more than one pooled transaction.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(10), keyB)); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(10), keyB)); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}
			},
		},
		{
			// This test is analogous to the previous one, but the the replaced
			// transaction is self-sponsored.
			name:    "allow-tx-from-replaced-self-sponsor-authority",
			pending: 3,
			run: func(name string) {
				// Send transaction from A with A as an authority.
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(10), uint256.NewInt(3), keyA, []unsignedAuth{{0, keyA}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				// Replace transaction with a transaction with B as an authority.
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(30), uint256.NewInt(30), keyA, []unsignedAuth{{0, keyB}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				// The one in-flight transaction limit from A no longer applies, so we
				// can stack a second transaction for the account.
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1000), keyA)); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}
				// B should still be able to send transactions.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1000), keyB)); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}
				// However B still has the limitation to one in-flight transaction.
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1), keyB)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, txpool.ErrInflightTxLimitReached, err)
				}
			},
		},
		{
			name:    "replacements-respect-inflight-tx-count",
			pending: 2,
			run: func(name string) {
				// Send transaction from A with B as an authority.
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(10), uint256.NewInt(3), keyA, []unsignedAuth{{0, keyB}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				// Send two transactions from B. Only the first should be accepted due
				// to in-flight limit.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1), keyB)); err != nil {
					t.Fatalf("%s: failed to add remote transaction: %v", name, err)
				}
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1), keyB)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, txpool.ErrInflightTxLimitReached, err)
				}
				// Replace the in-flight transaction from B.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(30), keyB)); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}
				// Ensure the in-flight limit for B is still in place.
				if err := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1), keyB)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, txpool.ErrInflightTxLimitReached, err)
				}
			},
		},
		{
			// Since multiple authorizations can be pending simultaneously, replacing
			// one of them should not break the one in-flight-transaction limit.
			name:    "track-multiple-conflicting-delegations",
			pending: 3,
			run: func(name string) {
				// Send two setcode txs both with C as an authority.
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(10), uint256.NewInt(3), keyA, []unsignedAuth{{0, keyC}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(30), uint256.NewInt(30), keyB, []unsignedAuth{{0, keyC}})); err != nil {
					t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
				}
				// Replace the tx from A with a non-setcode tx.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1000), keyA)); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}
				// Make sure we can only pool one tx from keyC since it is still a
				// pending authority.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1000), keyC)); err != nil {
					t.Fatalf("%s: failed to added single pooled for account with pending delegation: %v", name, err)
				}
				if err, want := pool.addRemoteSync(pricedTransaction(1, 100000, big.NewInt(1000), keyC)), txpool.ErrInflightTxLimitReached; !errors.Is(err, want) {
					t.Fatalf("%s: error mismatch: want %v, have %v", name, want, err)
				}
			},
		},
		{
			name:    "remove-hash-from-authority-tracker",
			pending: 10,
			run: func(name string) {
				var keys []*ecdsa.PrivateKey
				for i := 0; i < 30; i++ {
					key, _ := crypto.GenerateKey()
					keys = append(keys, key)
					addr := crypto.PubkeyToAddress(key.PublicKey)
					testAddBalance(pool, addr, big.NewInt(params.Ether))
				}
				// Create a transactions with 3 unique auths so the lookup's auth map is
				// filled with addresses.
				for i := 0; i < 30; i += 3 {
					if err := pool.addRemoteSync(pricedSetCodeTx(0, 250000, uint256.NewInt(10), uint256.NewInt(3), keys[i], []unsignedAuth{{0, keys[i]}, {0, keys[i+1]}, {0, keys[i+2]}})); err != nil {
						t.Fatalf("%s: failed to add with remote setcode transaction: %v", name, err)
					}
				}
				// Replace one of the transactions with a normal transaction so that the
				// original hash is removed from the tracker. The hash should be
				// associated with 3 different authorities.
				if err := pool.addRemoteSync(pricedTransaction(0, 100000, big.NewInt(1000), keys[0])); err != nil {
					t.Fatalf("%s: failed to replace with remote transaction: %v", name, err)
				}
			},
		},
	} {
		tt.run(tt.name)
		pending, queued := pool.Stats()
		if pending != tt.pending {
			t.Fatalf("%s: pending transactions mismatched: have %d, want %d", tt.name, pending, tt.pending)
		}
		if queued != tt.queued {
			t.Fatalf("%s: queued transactions mismatched: have %d, want %d", tt.name, queued, tt.queued)
		}
		if err := validatePoolInternals(pool); err != nil {
			t.Fatalf("%s: pool internal state corrupted: %v", tt.name, err)
		}
		pool.Clear()
	}
}

func TestSetCodeTransactionsReorg(t *testing.T) {
	t.Parallel()

	// Create the pool to test the status retrievals with
	statedb, _ := state.New(types.EmptyRootHash, state.NewDatabaseForTesting())
	blockchain := newTestBlockChain(params.MergedTestChainConfig, 1000000, statedb, new(event.Feed))

	pool := New(testTxPoolConfig, blockchain)
	pool.Init(testTxPoolConfig.PriceLimit, blockchain.CurrentBlock(), newReserver())
	defer pool.Close()

	// Create the test accounts
	var (
		keyA, _ = crypto.GenerateKey()
		addrA   = crypto.PubkeyToAddress(keyA.PublicKey)
	)
	testAddBalance(pool, addrA, big.NewInt(params.Ether))
	// Send an authorization for 0x42
	var authList []types.SetCodeAuthorization
	auth, _ := types.SignSetCode(keyA, types.SetCodeAuthorization{
		ChainID: *uint256.MustFromBig(params.TestChainConfig.ChainID),
		Address: common.Address{0x42},
		Nonce:   0,
	})
	authList = append(authList, auth)
	if err := pool.addRemoteSync(pricedSetCodeTxWithAuth(0, 250000, uint256.NewInt(10), uint256.NewInt(3), keyA, authList)); err != nil {
		t.Fatalf("failed to add with remote setcode transaction: %v", err)
	}
	// Simulate the chain moving
	blockchain.statedb.SetNonce(addrA, 1, tracing.NonceChangeAuthorization)
	blockchain.statedb.SetCode(addrA, types.AddressToDelegation(auth.Address))
	<-pool.requestReset(nil, nil)
	// Set an authorization for 0x00
	auth, _ = types.SignSetCode(keyA, types.SetCodeAuthorization{
		ChainID: *uint256.MustFromBig(params.TestChainConfig.ChainID),
		Address: common.Address{},
		Nonce:   0,
	})
	authList = append(authList, auth)
	if err := pool.addRemoteSync(pricedSetCodeTxWithAuth(1, 250000, uint256.NewInt(10), uint256.NewInt(3), keyA, authList)); err != nil {
		t.Fatalf("failed to add with remote setcode transaction: %v", err)
	}
	// Try to add a transactions in
	if err := pool.addRemoteSync(pricedTransaction(2, 100000, big.NewInt(1000), keyA)); !errors.Is(err, txpool.ErrInflightTxLimitReached) {
		t.Fatalf("unexpected error %v, expecting %v", err, txpool.ErrInflightTxLimitReached)
	}
	// Simulate the chain moving
	blockchain.statedb.SetNonce(addrA, 2, tracing.NonceChangeAuthorization)
	blockchain.statedb.SetCode(addrA, nil)
	<-pool.requestReset(nil, nil)
	// Now send two transactions from addrA
	if err := pool.addRemoteSync(pricedTransaction(2, 100000, big.NewInt(1000), keyA)); err != nil {
		t.Fatalf("failed to added single transaction: %v", err)
	}
	if err := pool.addRemoteSync(pricedTransaction(3, 100000, big.NewInt(1000), keyA)); err != nil {
		t.Fatalf("failed to added single transaction: %v", err)
	}
}

// Benchmarks the speed of validating the contents of the pending queue of the
// transaction pool.
func BenchmarkPendingDemotion100(b *testing.B)   { benchmarkPendingDemotion(b, 100) }
func BenchmarkPendingDemotion1000(b *testing.B)  { benchmarkPendingDemotion(b, 1000) }
func BenchmarkPendingDemotion10000(b *testing.B) { benchmarkPendingDemotion(b, 10000) }

func benchmarkPendingDemotion(b *testing.B, size int) {
	// Add a batch of transactions to a pool one by one
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000000))

	for i := 0; i < size; i++ {
		tx := transaction(uint64(i), 100000, key)
		pool.promoteTx(account, tx.Hash(), tx)
	}
	// Benchmark the speed of pool validation
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		pool.demoteUnexecutables()
	}
}

// Benchmarks the speed of scheduling the contents of the future queue of the
// transaction pool.
func BenchmarkFuturePromotion100(b *testing.B)   { benchmarkFuturePromotion(b, 100) }
func BenchmarkFuturePromotion1000(b *testing.B)  { benchmarkFuturePromotion(b, 1000) }
func BenchmarkFuturePromotion10000(b *testing.B) { benchmarkFuturePromotion(b, 10000) }

func benchmarkFuturePromotion(b *testing.B, size int) {
	// Add a batch of transactions to a pool one by one
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000000))

	for i := 0; i < size; i++ {
		tx := transaction(uint64(1+i), 100000, key)
		pool.enqueueTx(tx.Hash(), tx, true)
	}
	// Benchmark the speed of pool validation
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		pool.promoteExecutables(nil)
	}
}

// Benchmarks the speed of batched transaction insertion.
func BenchmarkBatchInsert100(b *testing.B)   { benchmarkBatchInsert(b, 100) }
func BenchmarkBatchInsert1000(b *testing.B)  { benchmarkBatchInsert(b, 1000) }
func BenchmarkBatchInsert10000(b *testing.B) { benchmarkBatchInsert(b, 10000) }

func benchmarkBatchInsert(b *testing.B, size int) {
	// Generate a batch of transactions to enqueue into the pool
	pool, key := setupPool()
	defer pool.Close()

	account := crypto.PubkeyToAddress(key.PublicKey)
	testAddBalance(pool, account, big.NewInt(1000000000000000000))

	batches := make([]types.Transactions, b.N)
	for i := 0; i < b.N; i++ {
		batches[i] = make(types.Transactions, size)
		for j := 0; j < size; j++ {
			batches[i][j] = transaction(uint64(size*i+j), 100000, key)
		}
	}
	// Benchmark importing the transactions into the queue
	b.ResetTimer()
	for _, batch := range batches {
		pool.addRemotes(batch)
	}
}

// Benchmarks the speed of batch transaction insertion in case of multiple accounts.
func BenchmarkMultiAccountBatchInsert(b *testing.B) {
	// Generate a batch of transactions to enqueue into the pool
	pool, _ := setupPool()
	defer pool.Close()
	b.ReportAllocs()
	batches := make(types.Transactions, b.N)
	for i := 0; i < b.N; i++ {
		key, _ := crypto.GenerateKey()
		account := crypto.PubkeyToAddress(key.PublicKey)
		pool.currentState.AddBalance(account, uint256.NewInt(1000000), tracing.BalanceChangeUnspecified)
		tx := transaction(uint64(0), 100000, key)
		batches[i] = tx
	}
	// Benchmark importing the transactions into the queue
	b.ResetTimer()
	for _, tx := range batches {
		pool.addRemotesSync([]*types.Transaction{tx})
	}
}