// Copyright 2021 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 js
import (
"encoding/json"
"errors"
"math/big"
"strings"
"testing"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/eth/tracers"
"github.com/ethereum/go-ethereum/params"
"github.com/holiman/uint256"
)
type account struct{}
func (account) SubBalance(amount *big.Int) {}
func (account) AddBalance(amount *big.Int) {}
func (account) SetAddress(common.Address) {}
func (account) Value() *big.Int { return nil }
func (account) SetBalance(*uint256.Int) {}
func (account) SetNonce(uint64) {}
func (account) Balance() *uint256.Int { return nil }
func (account) Address() common.Address { return common.Address{} }
func (account) SetCode(common.Hash, []byte) {}
func (account) ForEachStorage(cb func(key, value common.Hash) bool) {}
type dummyStatedb struct {
state.StateDB
}
func (*dummyStatedb) GetRefund() uint64 { return 1337 }
func (*dummyStatedb) GetBalance(addr common.Address) *uint256.Int { return new(uint256.Int) }
type vmContext struct {
blockCtx vm.BlockContext
txCtx vm.TxContext
}
func testCtx() *vmContext {
return &vmContext{blockCtx: vm.BlockContext{BlockNumber: big.NewInt(1)}, txCtx: vm.TxContext{GasPrice: big.NewInt(100000)}}
}
func runTrace(tracer *tracers.Tracer, vmctx *vmContext, chaincfg *params.ChainConfig, contractCode []byte) (json.RawMessage, error) {
var (
evm = vm.NewEVM(vmctx.blockCtx, &dummyStatedb{}, chaincfg, vm.Config{Tracer: tracer.Hooks})
gasLimit uint64 = 31000
startGas uint64 = 10000
value = uint256.NewInt(0)
contract = vm.NewContract(account{}, account{}, value, startGas)
)
evm.SetTxContext(vmctx.txCtx)
contract.Code = []byte{byte(vm.PUSH1), 0x1, byte(vm.PUSH1), 0x1, 0x0}
if contractCode != nil {
contract.Code = contractCode
}
tracer.OnTxStart(evm.GetVMContext(), types.NewTx(&types.LegacyTx{Gas: gasLimit}), contract.Caller())
tracer.OnEnter(0, byte(vm.CALL), contract.Caller(), contract.Address(), []byte{}, startGas, value.ToBig())
ret, err := evm.Interpreter().Run(contract, []byte{}, false)
tracer.OnExit(0, ret, startGas-contract.Gas, err, true)
// Rest gas assumes no refund
tracer.OnTxEnd(&types.Receipt{GasUsed: gasLimit - contract.Gas}, nil)
if err != nil {
return nil, err
}
return tracer.GetResult()
}
func TestTracer(t *testing.T) {
execTracer := func(code string, contract []byte) ([]byte, string) {
t.Helper()
chainConfig := params.TestChainConfig
tracer, err := newJsTracer(code, nil, nil, chainConfig)
if err != nil {
t.Fatal(err)
}
ret, err := runTrace(tracer, testCtx(), chainConfig, contract)
if err != nil {
return nil, err.Error() // Stringify to allow comparison without nil checks
}
return ret, ""
}
for i, tt := range []struct {
code string
want string
fail string
contract []byte
}{
{ // tests that we don't panic on bad arguments to memory access
code: "{depths: [], step: function(log) { this.depths.push(log.memory.slice(-1,-2)); }, fault: function() {}, result: function() { return this.depths; }}",
want: ``,
fail: "tracer accessed out of bound memory: offset -1, end -2 at step (<eval>:1:53(13)) in server-side tracer function 'step'",
}, { // tests that we don't panic on bad arguments to stack peeks
code: "{depths: [], step: function(log) { this.depths.push(log.stack.peek(-1)); }, fault: function() {}, result: function() { return this.depths; }}",
want: ``,
fail: "tracer accessed out of bound stack: size 0, index -1 at step (<eval>:1:53(11)) in server-side tracer function 'step'",
}, { // tests that we don't panic on bad arguments to memory getUint
code: "{ depths: [], step: function(log, db) { this.depths.push(log.memory.getUint(-64));}, fault: function() {}, result: function() { return this.depths; }}",
want: ``,
fail: "tracer accessed out of bound memory: available 0, offset -64, size 32 at step (<eval>:1:58(11)) in server-side tracer function 'step'",
}, { // tests some general counting
code: "{count: 0, step: function() { this.count += 1; }, fault: function() {}, result: function() { return this.count; }}",
want: `3`,
}, { // tests that depth is reported correctly
code: "{depths: [], step: function(log) { this.depths.push(log.stack.length()); }, fault: function() {}, result: function() { return this.depths; }}",
want: `[0,1,2]`,
}, { // tests memory length
code: "{lengths: [], step: function(log) { this.lengths.push(log.memory.length()); }, fault: function() {}, result: function() { return this.lengths; }}",
want: `[0,0,0]`,
}, { // tests to-string of opcodes
code: "{opcodes: [], step: function(log) { this.opcodes.push(log.op.toString()); }, fault: function() {}, result: function() { return this.opcodes; }}",
want: `["PUSH1","PUSH1","STOP"]`,
}, { // tests gasUsed
code: "{depths: [], step: function() {}, fault: function() {}, result: function(ctx) { return ctx.gasPrice+'.'+ctx.gasUsed; }}",
want: `"100000.21006"`,
}, {
code: "{res: null, step: function(log) {}, fault: function() {}, result: function() { return toWord('0xffaa') }}",
want: `{"0":0,"1":0,"2":0,"3":0,"4":0,"5":0,"6":0,"7":0,"8":0,"9":0,"10":0,"11":0,"12":0,"13":0,"14":0,"15":0,"16":0,"17":0,"18":0,"19":0,"20":0,"21":0,"22":0,"23":0,"24":0,"25":0,"26":0,"27":0,"28":0,"29":0,"30":255,"31":170}`,
}, { // test feeding a buffer back into go
code: "{res: null, step: function(log) { var address = log.contract.getAddress(); this.res = toAddress(address); }, fault: function() {}, result: function() { return this.res }}",
want: `{"0":0,"1":0,"2":0,"3":0,"4":0,"5":0,"6":0,"7":0,"8":0,"9":0,"10":0,"11":0,"12":0,"13":0,"14":0,"15":0,"16":0,"17":0,"18":0,"19":0}`,
}, {
code: "{res: null, step: function(log) { var address = '0x0000000000000000000000000000000000000000'; this.res = toAddress(address); }, fault: function() {}, result: function() { return this.res }}",
want: `{"0":0,"1":0,"2":0,"3":0,"4":0,"5":0,"6":0,"7":0,"8":0,"9":0,"10":0,"11":0,"12":0,"13":0,"14":0,"15":0,"16":0,"17":0,"18":0,"19":0}`,
}, {
code: "{res: null, step: function(log) { var address = Array.prototype.slice.call(log.contract.getAddress()); this.res = toAddress(address); }, fault: function() {}, result: function() { return this.res }}",
want: `{"0":0,"1":0,"2":0,"3":0,"4":0,"5":0,"6":0,"7":0,"8":0,"9":0,"10":0,"11":0,"12":0,"13":0,"14":0,"15":0,"16":0,"17":0,"18":0,"19":0}`,
}, {
code: "{res: [], step: function(log) { var op = log.op.toString(); if (op === 'MSTORE8' || op === 'STOP') { this.res.push(log.memory.slice(0, 2)) } }, fault: function() {}, result: function() { return this.res }}",
want: `[{"0":0,"1":0},{"0":255,"1":0}]`,
contract: []byte{byte(vm.PUSH1), byte(0xff), byte(vm.PUSH1), byte(0x00), byte(vm.MSTORE8), byte(vm.STOP)},
}, {
code: "{res: [], step: function(log) { if (log.op.toString() === 'STOP') { this.res.push(log.memory.slice(5, 1025 * 1024)) } }, fault: function() {}, result: function() { return this.res }}",
want: "",
fail: "reached limit for padding memory slice: 1049568 at step (<eval>:1:83(20)) in server-side tracer function 'step'",
contract: []byte{byte(vm.PUSH1), byte(0xff), byte(vm.PUSH1), byte(0x00), byte(vm.MSTORE8), byte(vm.STOP)},
}, { // tests ctx.coinbase
code: "{lengths: [], step: function(log) { }, fault: function() {}, result: function(ctx) { var coinbase = ctx.coinbase; return toAddress(coinbase); }}",
want: `{"0":0,"1":0,"2":0,"3":0,"4":0,"5":0,"6":0,"7":0,"8":0,"9":0,"10":0,"11":0,"12":0,"13":0,"14":0,"15":0,"16":0,"17":0,"18":0,"19":0}`,
},
} {
if have, err := execTracer(tt.code, tt.contract); tt.want != string(have) || tt.fail != err {
t.Errorf("testcase %d: expected return value to be \n'%s'\n\tgot\n'%s'\nerror to be\n'%s'\n\tgot\n'%s'\n\tcode: %v", i, tt.want, string(have), tt.fail, err, tt.code)
}
}
}
func TestHalt(t *testing.T) {
timeout := errors.New("stahp")
chainConfig := params.TestChainConfig
tracer, err := newJsTracer("{step: function() { while(1); }, result: function() { return null; }, fault: function(){}}", nil, nil, chainConfig)
if err != nil {
t.Fatal(err)
}
go func() {
time.Sleep(1 * time.Second)
tracer.Stop(timeout)
}()
if _, err = runTrace(tracer, testCtx(), chainConfig, nil); !strings.Contains(err.Error(), "stahp") {
t.Errorf("Expected timeout error, got %v", err)
}
}
func TestHaltBetweenSteps(t *testing.T) {
chainConfig := params.TestChainConfig
tracer, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }}", nil, nil, chainConfig)
if err != nil {
t.Fatal(err)
}
scope := &vm.ScopeContext{
Contract: vm.NewContract(&account{}, &account{}, uint256.NewInt(0), 0),
}
evm := vm.NewEVM(vm.BlockContext{BlockNumber: big.NewInt(1)}, &dummyStatedb{}, chainConfig, vm.Config{Tracer: tracer.Hooks})
evm.SetTxContext(vm.TxContext{GasPrice: big.NewInt(1)})
tracer.OnTxStart(evm.GetVMContext(), types.NewTx(&types.LegacyTx{}), common.Address{})
tracer.OnEnter(0, byte(vm.CALL), common.Address{}, common.Address{}, []byte{}, 0, big.NewInt(0))
tracer.OnOpcode(0, 0, 0, 0, scope, nil, 0, nil)
timeout := errors.New("stahp")
tracer.Stop(timeout)
tracer.OnOpcode(0, 0, 0, 0, scope, nil, 0, nil)
if _, err := tracer.GetResult(); !strings.Contains(err.Error(), timeout.Error()) {
t.Errorf("Expected timeout error, got %v", err)
}
}
// TestNoStepExec tests a regular value transfer (no exec), and accessing the statedb
// in 'result'
func TestNoStepExec(t *testing.T) {
execTracer := func(code string) []byte {
t.Helper()
chainConfig := params.TestChainConfig
tracer, err := newJsTracer(code, nil, nil, chainConfig)
if err != nil {
t.Fatal(err)
}
evm := vm.NewEVM(vm.BlockContext{BlockNumber: big.NewInt(1)}, &dummyStatedb{}, chainConfig, vm.Config{Tracer: tracer.Hooks})
evm.SetTxContext(vm.TxContext{GasPrice: big.NewInt(100)})
tracer.OnTxStart(evm.GetVMContext(), types.NewTx(&types.LegacyTx{}), common.Address{})
tracer.OnEnter(0, byte(vm.CALL), common.Address{}, common.Address{}, []byte{}, 1000, big.NewInt(0))
tracer.OnExit(0, nil, 0, nil, false)
ret, err := tracer.GetResult()
if err != nil {
t.Fatal(err)
}
return ret
}
for i, tt := range []struct {
code string
want string
}{
{ // tests that we don't panic on accessing the db methods
code: "{depths: [], step: function() {}, fault: function() {}, result: function(ctx, db){ return db.getBalance(ctx.to)} }",
want: `"0"`,
},
} {
if have := execTracer(tt.code); tt.want != string(have) {
t.Errorf("testcase %d: expected return value to be %s got %s\n\tcode: %v", i, tt.want, string(have), tt.code)
}
}
}
func TestIsPrecompile(t *testing.T) {
chaincfg := ¶ms.ChainConfig{ChainID: big.NewInt(1), HomesteadBlock: big.NewInt(0), DAOForkBlock: nil, DAOForkSupport: false, EIP150Block: big.NewInt(0), EIP155Block: big.NewInt(0), EIP158Block: big.NewInt(0), ByzantiumBlock: big.NewInt(100), ConstantinopleBlock: big.NewInt(0), PetersburgBlock: big.NewInt(0), IstanbulBlock: big.NewInt(200), MuirGlacierBlock: big.NewInt(0), BerlinBlock: big.NewInt(300), LondonBlock: big.NewInt(0), TerminalTotalDifficulty: nil, Ethash: new(params.EthashConfig), Clique: nil}
chaincfg.ByzantiumBlock = big.NewInt(100)
chaincfg.IstanbulBlock = big.NewInt(200)
chaincfg.BerlinBlock = big.NewInt(300)
txCtx := vm.TxContext{GasPrice: big.NewInt(100000)}
tracer, err := newJsTracer("{addr: toAddress('0000000000000000000000000000000000000009'), res: null, step: function() { this.res = isPrecompiled(this.addr); }, fault: function() {}, result: function() { return this.res; }}", nil, nil, chaincfg)
if err != nil {
t.Fatal(err)
}
blockCtx := vm.BlockContext{BlockNumber: big.NewInt(150)}
res, err := runTrace(tracer, &vmContext{blockCtx, txCtx}, chaincfg, nil)
if err != nil {
t.Error(err)
}
if string(res) != "false" {
t.Errorf("tracer should not consider blake2f as precompile in byzantium")
}
tracer, _ = newJsTracer("{addr: toAddress('0000000000000000000000000000000000000009'), res: null, step: function() { this.res = isPrecompiled(this.addr); }, fault: function() {}, result: function() { return this.res; }}", nil, nil, chaincfg)
blockCtx = vm.BlockContext{BlockNumber: big.NewInt(250)}
res, err = runTrace(tracer, &vmContext{blockCtx, txCtx}, chaincfg, nil)
if err != nil {
t.Error(err)
}
if string(res) != "true" {
t.Errorf("tracer should consider blake2f as precompile in istanbul")
}
}
func TestEnterExit(t *testing.T) {
chainConfig := params.TestChainConfig
// test that either both or none of enter() and exit() are defined
if _, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }, enter: function() {}}", new(tracers.Context), nil, chainConfig); err == nil {
t.Fatal("tracer creation should've failed without exit() definition")
}
if _, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }, enter: function() {}, exit: function() {}}", new(tracers.Context), nil, chainConfig); err != nil {
t.Fatal(err)
}
// test that the enter and exit method are correctly invoked and the values passed
tracer, err := newJsTracer("{enters: 0, exits: 0, enterGas: 0, gasUsed: 0, step: function() {}, fault: function() {}, result: function() { return {enters: this.enters, exits: this.exits, enterGas: this.enterGas, gasUsed: this.gasUsed} }, enter: function(frame) { this.enters++; this.enterGas = frame.getGas(); }, exit: function(res) { this.exits++; this.gasUsed = res.getGasUsed(); }}", new(tracers.Context), nil, chainConfig)
if err != nil {
t.Fatal(err)
}
scope := &vm.ScopeContext{
Contract: vm.NewContract(&account{}, &account{}, uint256.NewInt(0), 0),
}
tracer.OnEnter(1, byte(vm.CALL), scope.Contract.Caller(), scope.Contract.Address(), []byte{}, 1000, new(big.Int))
tracer.OnExit(1, []byte{}, 400, nil, false)
have, err := tracer.GetResult()
if err != nil {
t.Fatal(err)
}
want := `{"enters":1,"exits":1,"enterGas":1000,"gasUsed":400}`
if string(have) != want {
t.Errorf("Number of invocations of enter() and exit() is wrong. Have %s, want %s\n", have, want)
}
}
func TestSetup(t *testing.T) {
// Test empty config
chainConfig := params.TestChainConfig
_, err := newJsTracer(`{setup: function(cfg) { if (cfg !== "{}") { throw("invalid empty config") } }, fault: function() {}, result: function() {}}`, new(tracers.Context), nil, chainConfig)
if err != nil {
t.Error(err)
}
cfg, err := json.Marshal(map[string]string{"foo": "bar"})
if err != nil {
t.Fatal(err)
}
// Test no setup func
_, err = newJsTracer(`{fault: function() {}, result: function() {}}`, new(tracers.Context), cfg, chainConfig)
if err != nil {
t.Fatal(err)
}
// Test config value
tracer, err := newJsTracer("{config: null, setup: function(cfg) { this.config = JSON.parse(cfg) }, step: function() {}, fault: function() {}, result: function() { return this.config.foo }}", new(tracers.Context), cfg, chainConfig)
if err != nil {
t.Fatal(err)
}
have, err := tracer.GetResult()
if err != nil {
t.Fatal(err)
}
if string(have) != `"bar"` {
t.Errorf("tracer returned wrong result. have: %s, want: \"bar\"\n", string(have))
}
}