console, internal/jsre: use github.com/dop251/goja (#20470)

This replaces the JavaScript interpreter used by the console with goja,
which is actively maintained and a lot faster than otto. Clef still uses otto
and eth/tracers still uses duktape, so we are currently dependent on three
different JS interpreters. We're looking to replace the remaining uses of otto
soon though.

cmd/geth/consolecmd_test.go

@@ -51,7 +51,9 @@ func TestConsoleWelcome(t *testing.T) {
 	geth.SetTemplateFunc("goarch", func() string { return runtime.GOARCH })
 	geth.SetTemplateFunc("gover", runtime.Version)
 	geth.SetTemplateFunc("gethver", func() string { return params.VersionWithCommit("", "") })
-	geth.SetTemplateFunc("niltime", func() string { return time.Unix(0, 0).Format(time.RFC1123) })
+	geth.SetTemplateFunc("niltime", func() string {
+		return time.Unix(0, 0).Format("Mon Jan 02 2006 15:04:05 GMT-0700 (MST)")
+	})
 	geth.SetTemplateFunc("apis", func() string { return ipcAPIs })
 
 	// Verify the actual welcome message to the required template
@@ -142,7 +144,9 @@ func testAttachWelcome(t *testing.T, geth *testgeth, endpoint, apis string) {
 	attach.SetTemplateFunc("gover", runtime.Version)
 	attach.SetTemplateFunc("gethver", func() string { return params.VersionWithCommit("", "") })
 	attach.SetTemplateFunc("etherbase", func() string { return geth.Etherbase })
-	attach.SetTemplateFunc("niltime", func() string { return time.Unix(0, 0).Format(time.RFC1123) })
+	attach.SetTemplateFunc("niltime", func() string {
+		return time.Unix(0, 0).Format("Mon Jan 02 2006 15:04:05 GMT-0700 (MST)")
+	})
 	attach.SetTemplateFunc("ipc", func() bool { return strings.HasPrefix(endpoint, "ipc") })
 	attach.SetTemplateFunc("datadir", func() string { return geth.Datadir })
 	attach.SetTemplateFunc("apis", func() string { return apis })

console/console_test.go

@@ -289,7 +289,7 @@ func TestPrettyError(t *testing.T) {
 	defer tester.Close(t)
 	tester.console.Evaluate("throw 'hello'")
 
-	want := jsre.ErrorColor("hello") + "\n"
+	want := jsre.ErrorColor("hello") + "\n\tat <eval>:1:7(1)\n\n"
 	if output := tester.output.String(); output != want {
 		t.Fatalf("pretty error mismatch: have %s, want %s", output, want)
 	}

go.mod

@@ -16,13 +16,16 @@ require (
 	github.com/cloudflare/cloudflare-go v0.10.2-0.20190916151808-a80f83b9add9
 	github.com/davecgh/go-spew v1.1.1
 	github.com/deckarep/golang-set v0.0.0-20180603214616-504e848d77ea
+	github.com/dlclark/regexp2 v1.2.0 // indirect
 	github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf
+	github.com/dop251/goja v0.0.0-20200106141417-aaec0e7bde29
 	github.com/edsrzf/mmap-go v0.0.0-20160512033002-935e0e8a636c
 	github.com/elastic/gosigar v0.8.1-0.20180330100440-37f05ff46ffa
 	github.com/fatih/color v1.3.0
 	github.com/fjl/memsize v0.0.0-20180418122429-ca190fb6ffbc
 	github.com/gballet/go-libpcsclite v0.0.0-20190607065134-2772fd86a8ff
 	github.com/go-ole/go-ole v1.2.1 // indirect
+	github.com/go-sourcemap/sourcemap v2.1.2+incompatible // indirect
 	github.com/go-stack/stack v1.8.0
 	github.com/golang/protobuf v1.3.2-0.20190517061210-b285ee9cfc6c
 	github.com/golang/snappy v0.0.1

go.sum

@@ -57,8 +57,14 @@ github.com/deckarep/golang-set v0.0.0-20180603214616-504e848d77ea/go.mod h1:93vs
 github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
+github.com/dlclark/regexp2 v1.2.0 h1:8sAhBGEM0dRWogWqWyQeIJnxjWO6oIjl8FKqREDsGfk=
+github.com/dlclark/regexp2 v1.2.0/go.mod h1:2pZnwuY/m+8K6iRw6wQdMtk+rH5tNGR1i55kozfMjCc=
 github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf h1:sh8rkQZavChcmakYiSlqu2425CHyFXLZZnvm7PDpU8M=
 github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/dop251/goja v0.0.0-20191203121440-007eef3bc40f h1:vtCDQseO/Sbu5IZSoc2uzZ7CkSoai7OtpcwGFK5FlyE=
+github.com/dop251/goja v0.0.0-20191203121440-007eef3bc40f/go.mod h1:Mw6PkjjMXWbTj+nnj4s3QPXq1jaT0s5pC0iFD4+BOAA=
+github.com/dop251/goja v0.0.0-20200106141417-aaec0e7bde29 h1:Ewd9K+mC725sITA12QQHRqWj78NU4t7EhlFVVgdlzJg=
+github.com/dop251/goja v0.0.0-20200106141417-aaec0e7bde29/go.mod h1:Mw6PkjjMXWbTj+nnj4s3QPXq1jaT0s5pC0iFD4+BOAA=
 github.com/edsrzf/mmap-go v0.0.0-20160512033002-935e0e8a636c h1:JHHhtb9XWJrGNMcrVP6vyzO4dusgi/HnceHTgxSejUM=
 github.com/edsrzf/mmap-go v0.0.0-20160512033002-935e0e8a636c/go.mod h1:YO35OhQPt3KJa3ryjFM5Bs14WD66h8eGKpfaBNrHW5M=
 github.com/elastic/gosigar v0.8.1-0.20180330100440-37f05ff46ffa h1:XKAhUk/dtp+CV0VO6mhG2V7jA9vbcGcnYF/Ay9NjZrY=
@@ -77,6 +83,8 @@ github.com/go-logfmt/logfmt v0.3.0 h1:8HUsc87TaSWLKwrnumgC8/YconD2fJQsRJAsWaPg2i
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
 github.com/go-ole/go-ole v1.2.1 h1:2lOsA72HgjxAuMlKpFiCbHTvu44PIVkZ5hqm3RSdI/E=
 github.com/go-ole/go-ole v1.2.1/go.mod h1:7FAglXiTm7HKlQRDeOQ6ZNUHidzCWXuZWq/1dTyBNF8=
+github.com/go-sourcemap/sourcemap v2.1.2+incompatible h1:0b/xya7BKGhXuqFESKM4oIiRo9WOt2ebz7KxfreD6ug=
+github.com/go-sourcemap/sourcemap v2.1.2+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg=
 github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=

internal/jsre/completion.go

@@ -20,35 +20,43 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/robertkrimen/otto"
+	"github.com/dop251/goja"
 )
 
 // CompleteKeywords returns potential continuations for the given line. Since line is
 // evaluated, callers need to make sure that evaluating line does not have side effects.
 func (jsre *JSRE) CompleteKeywords(line string) []string {
 	var results []string
-	jsre.Do(func(vm *otto.Otto) {
+	jsre.Do(func(vm *goja.Runtime) {
 		results = getCompletions(vm, line)
 	})
 	return results
 }
 
-func getCompletions(vm *otto.Otto, line string) (results []string) {
+func getCompletions(vm *goja.Runtime, line string) (results []string) {
 	parts := strings.Split(line, ".")
-	objRef := "this"
-	prefix := line
-	if len(parts) > 1 {
-		objRef = strings.Join(parts[0:len(parts)-1], ".")
-		prefix = parts[len(parts)-1]
+	if len(parts) == 0 {
+		return nil
 	}
 
-	obj, _ := vm.Object(objRef)
-	if obj == nil {
-		return nil
+	// Find the right-most fully named object in the line. e.g. if line = "x.y.z"
+	// and "x.y" is an object, obj will reference "x.y".
+	obj := vm.GlobalObject()
+	for i := 0; i < len(parts)-1; i++ {
+		v := obj.Get(parts[i])
+		if v == nil {
+			return nil // No object was found
+		}
+		obj = v.ToObject(vm)
 	}
+
+	// Go over the keys of the object and retain the keys matching prefix.
+	// Example: if line = "x.y.z" and "x.y" exists and has keys "zebu", "zebra"
+	// and "platypus", then "x.y.zebu" and "x.y.zebra" will be added to results.
+	prefix := parts[len(parts)-1]
 	iterOwnAndConstructorKeys(vm, obj, func(k string) {
 		if strings.HasPrefix(k, prefix) {
-			if objRef == "this" {
+			if len(parts) == 1 {
 				results = append(results, k)
 			} else {
 				results = append(results, strings.Join(parts[:len(parts)-1], ".")+"."+k)
@@ -59,9 +67,9 @@ func getCompletions(vm *otto.Otto, line string) (results []string) {
 	// Append opening parenthesis (for functions) or dot (for objects)
 	// if the line itself is the only completion.
 	if len(results) == 1 && results[0] == line {
-		obj, _ := vm.Object(line)
+		obj := obj.Get(parts[len(parts)-1])
 		if obj != nil {
-			if obj.Class() == "Function" {
+			if _, isfunc := goja.AssertFunction(obj); isfunc {
 				results[0] += "("
 			} else {
 				results[0] += "."

internal/jsre/completion_test.go

@@ -39,6 +39,10 @@ func TestCompleteKeywords(t *testing.T) {
 		input string
 		want  []string
 	}{
+		{
+			input: "St",
+			want:  []string{"String"},
+		},
 		{
 			input: "x",
 			want:  []string{"x."},

internal/jsre/jsre_test.go

@@ -20,25 +20,24 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"reflect"
 	"testing"
 	"time"
 
-	"github.com/robertkrimen/otto"
+	"github.com/dop251/goja"
 )
 
-type testNativeObjectBinding struct{}
+type testNativeObjectBinding struct {
+	vm *goja.Runtime
+}
 
 type msg struct {
 	Msg string
 }
 
-func (no *testNativeObjectBinding) TestMethod(call otto.FunctionCall) otto.Value {
-	m, err := call.Argument(0).ToString()
-	if err != nil {
-		return otto.UndefinedValue()
-	}
-	v, _ := call.Otto.ToValue(&msg{m})
-	return v
+func (no *testNativeObjectBinding) TestMethod(call goja.FunctionCall) goja.Value {
+	m := call.Argument(0).ToString().String()
+	return no.vm.ToValue(&msg{m})
 }
 
 func newWithTestJS(t *testing.T, testjs string) (*JSRE, string) {
@@ -51,7 +50,8 @@ func newWithTestJS(t *testing.T, testjs string) (*JSRE, string) {
 			t.Fatal("cannot create test.js:", err)
 		}
 	}
-	return New(dir, os.Stdout), dir
+	jsre := New(dir, os.Stdout)
+	return jsre, dir
 }
 
 func TestExec(t *testing.T) {
@@ -66,11 +66,11 @@ func TestExec(t *testing.T) {
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	}
-	if !val.IsString() {
+	if val.ExportType().Kind() != reflect.String {
 		t.Errorf("expected string value, got %v", val)
 	}
 	exp := "testMsg"
-	got, _ := val.ToString()
+	got := val.ToString().String()
 	if exp != got {
 		t.Errorf("expected '%v', got '%v'", exp, got)
 	}
@@ -90,11 +90,11 @@ func TestNatto(t *testing.T) {
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	}
-	if !val.IsString() {
+	if val.ExportType().Kind() != reflect.String {
 		t.Errorf("expected string value, got %v", val)
 	}
 	exp := "testMsg"
-	got, _ := val.ToString()
+	got := val.ToString().String()
 	if exp != got {
 		t.Errorf("expected '%v', got '%v'", exp, got)
 	}
@@ -105,7 +105,7 @@ func TestBind(t *testing.T) {
 	jsre := New("", os.Stdout)
 	defer jsre.Stop(false)
 
-	jsre.Bind("no", &testNativeObjectBinding{})
+	jsre.Set("no", &testNativeObjectBinding{vm: jsre.vm})
 
 	_, err := jsre.Run(`no.TestMethod("testMsg")`)
 	if err != nil {
@@ -125,11 +125,11 @@ func TestLoadScript(t *testing.T) {
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	}
-	if !val.IsString() {
+	if val.ExportType().Kind() != reflect.String {
 		t.Errorf("expected string value, got %v", val)
 	}
 	exp := "testMsg"
-	got, _ := val.ToString()
+	got := val.ToString().String()
 	if exp != got {
 		t.Errorf("expected '%v', got '%v'", exp, got)
 	}

internal/jsre/pretty.go

@@ -19,12 +19,13 @@ package jsre
 import (
 	"fmt"
 	"io"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
 
+	"github.com/dop251/goja"
 	"github.com/fatih/color"
-	"github.com/robertkrimen/otto"
 )
 
 const (
@@ -52,29 +53,29 @@ var boringKeys = map[string]bool{
 }
 
 // prettyPrint writes value to standard output.
-func prettyPrint(vm *otto.Otto, value otto.Value, w io.Writer) {
+func prettyPrint(vm *goja.Runtime, value goja.Value, w io.Writer) {
 	ppctx{vm: vm, w: w}.printValue(value, 0, false)
 }
 
 // prettyError writes err to standard output.
-func prettyError(vm *otto.Otto, err error, w io.Writer) {
+func prettyError(vm *goja.Runtime, err error, w io.Writer) {
 	failure := err.Error()
-	if ottoErr, ok := err.(*otto.Error); ok {
-		failure = ottoErr.String()
+	if gojaErr, ok := err.(*goja.Exception); ok {
+		failure = gojaErr.String()
 	}
 	fmt.Fprint(w, ErrorColor("%s", failure))
 }
 
-func (re *JSRE) prettyPrintJS(call otto.FunctionCall) otto.Value {
-	for _, v := range call.ArgumentList {
-		prettyPrint(call.Otto, v, re.output)
+func (re *JSRE) prettyPrintJS(call goja.FunctionCall) goja.Value {
+	for _, v := range call.Arguments {
+		prettyPrint(re.vm, v, re.output)
 		fmt.Fprintln(re.output)
 	}
-	return otto.UndefinedValue()
+	return goja.Undefined()
 }
 
 type ppctx struct {
-	vm *otto.Otto
+	vm *goja.Runtime
 	w  io.Writer
 }
 
@@ -82,35 +83,47 @@ func (ctx ppctx) indent(level int) string {
 	return strings.Repeat(indentString, level)
 }
 
-func (ctx ppctx) printValue(v otto.Value, level int, inArray bool) {
+func (ctx ppctx) printValue(v goja.Value, level int, inArray bool) {
+	if goja.IsNull(v) || goja.IsUndefined(v) {
+		fmt.Fprint(ctx.w, SpecialColor(v.String()))
+		return
+	}
+	kind := v.ExportType().Kind()
 	switch {
-	case v.IsObject():
-		ctx.printObject(v.Object(), level, inArray)
-	case v.IsNull():
-		fmt.Fprint(ctx.w, SpecialColor("null"))
-	case v.IsUndefined():
-		fmt.Fprint(ctx.w, SpecialColor("undefined"))
-	case v.IsString():
-		s, _ := v.ToString()
-		fmt.Fprint(ctx.w, StringColor("%q", s))
-	case v.IsBoolean():
-		b, _ := v.ToBoolean()
-		fmt.Fprint(ctx.w, SpecialColor("%t", b))
-	case v.IsNaN():
-		fmt.Fprint(ctx.w, NumberColor("NaN"))
-	case v.IsNumber():
-		s, _ := v.ToString()
-		fmt.Fprint(ctx.w, NumberColor("%s", s))
+	case kind == reflect.Bool:
+		fmt.Fprint(ctx.w, SpecialColor("%t", v.ToBoolean()))
+	case kind == reflect.String:
+		fmt.Fprint(ctx.w, StringColor("%q", v.String()))
+	case kind >= reflect.Int && kind <= reflect.Complex128:
+		fmt.Fprint(ctx.w, NumberColor("%s", v.String()))
 	default:
-		fmt.Fprint(ctx.w, "<unprintable>")
+		if obj, ok := v.(*goja.Object); ok {
+			ctx.printObject(obj, level, inArray)
+		} else {
+			fmt.Fprintf(ctx.w, "<unprintable %T>", v)
+		}
 	}
 }
 
-func (ctx ppctx) printObject(obj *otto.Object, level int, inArray bool) {
-	switch obj.Class() {
+// SafeGet attempt to get the value associated to `key`, and
+// catches the panic that goja creates if an error occurs in
+// key.
+func SafeGet(obj *goja.Object, key string) (ret goja.Value) {
+	defer func() {
+		if r := recover(); r != nil {
+			ret = goja.Undefined()
+		}
+	}()
+	ret = obj.Get(key)
+
+	return ret
+}
+
+func (ctx ppctx) printObject(obj *goja.Object, level int, inArray bool) {
+	switch obj.ClassName() {
 	case "Array", "GoArray":
-		lv, _ := obj.Get("length")
-		len, _ := lv.ToInteger()
+		lv := obj.Get("length")
+		len := lv.ToInteger()
 		if len == 0 {
 			fmt.Fprintf(ctx.w, "[]")
 			return
@@ -121,8 +134,8 @@ func (ctx ppctx) printObject(obj *otto.Object, level int, inArray bool) {
 		}
 		fmt.Fprint(ctx.w, "[")
 		for i := int64(0); i < len; i++ {
-			el, err := obj.Get(strconv.FormatInt(i, 10))
-			if err == nil {
+			el := obj.Get(strconv.FormatInt(i, 10))
+			if el != nil {
 				ctx.printValue(el, level+1, true)
 			}
 			if i < len-1 {
@@ -149,7 +162,7 @@ func (ctx ppctx) printObject(obj *otto.Object, level int, inArray bool) {
 		}
 		fmt.Fprintln(ctx.w, "{")
 		for i, k := range keys {
-			v, _ := obj.Get(k)
+			v := SafeGet(obj, k)
 			fmt.Fprintf(ctx.w, "%s%s: ", ctx.indent(level+1), k)
 			ctx.printValue(v, level+1, false)
 			if i < len(keys)-1 {
@@ -163,29 +176,25 @@ func (ctx ppctx) printObject(obj *otto.Object, level int, inArray bool) {
 		fmt.Fprintf(ctx.w, "%s}", ctx.indent(level))
 
 	case "Function":
-		// Use toString() to display the argument list if possible.
-		if robj, err := obj.Call("toString"); err != nil {
-			fmt.Fprint(ctx.w, FunctionColor("function()"))
-		} else {
-			desc := strings.Trim(strings.Split(robj.String(), "{")[0], " \t\n")
-			desc = strings.Replace(desc, " (", "(", 1)
-			fmt.Fprint(ctx.w, FunctionColor("%s", desc))
-		}
+		robj := obj.ToString()
+		desc := strings.Trim(strings.Split(robj.String(), "{")[0], " \t\n")
+		desc = strings.Replace(desc, " (", "(", 1)
+		fmt.Fprint(ctx.w, FunctionColor("%s", desc))
 
 	case "RegExp":
 		fmt.Fprint(ctx.w, StringColor("%s", toString(obj)))
 
 	default:
-		if v, _ := obj.Get("toString"); v.IsFunction() && level <= maxPrettyPrintLevel {
-			s, _ := obj.Call("toString")
-			fmt.Fprintf(ctx.w, "<%s %s>", obj.Class(), s.String())
+		if level <= maxPrettyPrintLevel {
+			s := obj.ToString().String()
+			fmt.Fprintf(ctx.w, "<%s %s>", obj.ClassName(), s)
 		} else {
-			fmt.Fprintf(ctx.w, "<%s>", obj.Class())
+			fmt.Fprintf(ctx.w, "<%s>", obj.ClassName())
 		}
 	}
 }
 
-func (ctx ppctx) fields(obj *otto.Object) []string {
+func (ctx ppctx) fields(obj *goja.Object) []string {
 	var (
 		vals, methods []string
 		seen          = make(map[string]bool)
@@ -195,11 +204,22 @@ func (ctx ppctx) fields(obj *otto.Object) []string {
 			return
 		}
 		seen[k] = true
-		if v, _ := obj.Get(k); v.IsFunction() {
-			methods = append(methods, k)
-		} else {
+
+		key := SafeGet(obj, k)
+		if key == nil {
+			// The value corresponding to that key could not be found
+			// (typically because it is backed by an RPC call that is
+			// not supported by this instance.  Add it to the list of
+			// values so that it appears as `undefined` to the user.
 			vals = append(vals, k)
+		} else {
+			if _, callable := goja.AssertFunction(key); callable {
+				methods = append(methods, k)
+			} else {
+				vals = append(vals, k)
+			}
 		}
+
 	}
 	iterOwnAndConstructorKeys(ctx.vm, obj, add)
 	sort.Strings(vals)
@@ -207,13 +227,13 @@ func (ctx ppctx) fields(obj *otto.Object) []string {
 	return append(vals, methods...)
 }
 
-func iterOwnAndConstructorKeys(vm *otto.Otto, obj *otto.Object, f func(string)) {
+func iterOwnAndConstructorKeys(vm *goja.Runtime, obj *goja.Object, f func(string)) {
 	seen := make(map[string]bool)
 	iterOwnKeys(vm, obj, func(prop string) {
 		seen[prop] = true
 		f(prop)
 	})
-	if cp := constructorPrototype(obj); cp != nil {
+	if cp := constructorPrototype(vm, obj); cp != nil {
 		iterOwnKeys(vm, cp, func(prop string) {
 			if !seen[prop] {
 				f(prop)
@@ -222,10 +242,17 @@ func iterOwnAndConstructorKeys(vm *otto.Otto, obj *otto.Object, f func(string))
 	}
 }
 
-func iterOwnKeys(vm *otto.Otto, obj *otto.Object, f func(string)) {
-	Object, _ := vm.Object("Object")
-	rv, _ := Object.Call("getOwnPropertyNames", obj.Value())
-	gv, _ := rv.Export()
+func iterOwnKeys(vm *goja.Runtime, obj *goja.Object, f func(string)) {
+	Object := vm.Get("Object").ToObject(vm)
+	getOwnPropertyNames, isFunc := goja.AssertFunction(Object.Get("getOwnPropertyNames"))
+	if !isFunc {
+		panic(vm.ToValue("Object.getOwnPropertyNames isn't a function"))
+	}
+	rv, err := getOwnPropertyNames(goja.Null(), obj)
+	if err != nil {
+		panic(vm.ToValue(fmt.Sprintf("Error getting object properties: %v", err)))
+	}
+	gv := rv.Export()
 	switch gv := gv.(type) {
 	case []interface{}:
 		for _, v := range gv {
@@ -240,32 +267,35 @@ func iterOwnKeys(vm *otto.Otto, obj *otto.Object, f func(string)) {
 	}
 }
 
-func (ctx ppctx) isBigNumber(v *otto.Object) bool {
+func (ctx ppctx) isBigNumber(v *goja.Object) bool {
 	// Handle numbers with custom constructor.
-	if v, _ := v.Get("constructor"); v.Object() != nil {
-		if strings.HasPrefix(toString(v.Object()), "function BigNumber") {
+	if obj := v.Get("constructor").ToObject(ctx.vm); obj != nil {
+		if strings.HasPrefix(toString(obj), "function BigNumber") {
 			return true
 		}
 	}
 	// Handle default constructor.
-	BigNumber, _ := ctx.vm.Object("BigNumber.prototype")
+	BigNumber := ctx.vm.Get("BigNumber").ToObject(ctx.vm)
 	if BigNumber == nil {
 		return false
 	}
-	bv, _ := BigNumber.Call("isPrototypeOf", v)
-	b, _ := bv.ToBoolean()
-	return b
+	prototype := BigNumber.Get("prototype").ToObject(ctx.vm)
+	isPrototypeOf, callable := goja.AssertFunction(prototype.Get("isPrototypeOf"))
+	if !callable {
+		return false
+	}
+	bv, _ := isPrototypeOf(prototype, v)
+	return bv.ToBoolean()
 }
 
-func toString(obj *otto.Object) string {
-	s, _ := obj.Call("toString")
-	return s.String()
+func toString(obj *goja.Object) string {
+	return obj.ToString().String()
 }
 
-func constructorPrototype(obj *otto.Object) *otto.Object {
-	if v, _ := obj.Get("constructor"); v.Object() != nil {
-		if v, _ = v.Object().Get("prototype"); v.Object() != nil {
-			return v.Object()
+func constructorPrototype(vm *goja.Runtime, obj *goja.Object) *goja.Object {
+	if v := obj.Get("constructor"); v != nil {
+		if v := v.ToObject(vm).Get("prototype"); v != nil {
+			return v.ToObject(vm)
 		}
 	}
 	return nil