// 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 jsre
import (
"fmt"
"sort"
"strconv"
"strings"
"github.com/fatih/color"
"github.com/robertkrimen/otto"
)
const (
maxPrettyPrintLevel = 3
indentString = " "
)
var (
functionColor = color.New(color.FgMagenta)
specialColor = color.New(color.Bold)
numberColor = color.New(color.FgRed)
stringColor = color.New(color.FgGreen)
)
// these fields are hidden when printing objects.
var boringKeys = map[string]bool{
"valueOf": true,
"toString": true,
"toLocaleString": true,
"hasOwnProperty": true,
"isPrototypeOf": true,
"propertyIsEnumerable": true,
"constructor": true,
}
// prettyPrint writes value to standard output.
func prettyPrint(vm *otto.Otto, value otto.Value) {
ppctx{vm}.printValue(value, 0, false)
}
func prettyPrintJS(call otto.FunctionCall) otto.Value {
for _, v := range call.ArgumentList {
prettyPrint(call.Otto, v)
fmt.Println()
}
return otto.UndefinedValue()
}
type ppctx struct{ vm *otto.Otto }
func (ctx ppctx) indent(level int) string {
return strings.Repeat(indentString, level)
}
func (ctx ppctx) printValue(v otto.Value, level int, inArray bool) {
switch {
case v.IsObject():
ctx.printObject(v.Object(), level, inArray)
case v.IsNull():
specialColor.Print("null")
case v.IsUndefined():
specialColor.Print("undefined")
case v.IsString():
s, _ := v.ToString()
stringColor.Printf("%q", s)
case v.IsBoolean():
b, _ := v.ToBoolean()
specialColor.Printf("%t", b)
case v.IsNaN():
numberColor.Printf("NaN")
case v.IsNumber():
s, _ := v.ToString()
numberColor.Printf("%s", s)
default:
fmt.Printf("<unprintable>")
}
}
func (ctx ppctx) printObject(obj *otto.Object, level int, inArray bool) {
switch obj.Class() {
case "Array":
lv, _ := obj.Get("length")
len, _ := lv.ToInteger()
if len == 0 {
fmt.Printf("[]")
return
}
if level > maxPrettyPrintLevel {
fmt.Print("[...]")
return
}
fmt.Print("[")
for i := int64(0); i < len; i++ {
el, err := obj.Get(strconv.FormatInt(i, 10))
if err == nil {
ctx.printValue(el, level+1, true)
}
if i < len-1 {
fmt.Printf(", ")
}
}
fmt.Print("]")
case "Object":
// Print values from bignumber.js as regular numbers.
if ctx.isBigNumber(obj) {
numberColor.Print(toString(obj))
return
}
// Otherwise, print all fields indented, but stop if we're too deep.
keys := ctx.fields(obj)
if len(keys) == 0 {
fmt.Print("{}")
return
}
if level > maxPrettyPrintLevel {
fmt.Print("{...}")
return
}
fmt.Println("{")
for i, k := range keys {
v, _ := obj.Get(k)
fmt.Printf("%s%s: ", ctx.indent(level+1), k)
ctx.printValue(v, level+1, false)
if i < len(keys)-1 {
fmt.Printf(",")
}
fmt.Println()
}
if inArray {
level--
}
fmt.Printf("%s}", ctx.indent(level))
case "Function":
// Use toString() to display the argument list if possible.
if robj, err := obj.Call("toString"); err != nil {
functionColor.Print("function()")
} else {
desc := strings.Trim(strings.Split(robj.String(), "{")[0], " \t\n")
desc = strings.Replace(desc, " (", "(", 1)
functionColor.Print(desc)
}
case "RegExp":
stringColor.Print(toString(obj))
default:
if v, _ := obj.Get("toString"); v.IsFunction() && level <= maxPrettyPrintLevel {
s, _ := obj.Call("toString")
fmt.Printf("<%s %s>", obj.Class(), s.String())
} else {
fmt.Printf("<%s>", obj.Class())
}
}
}
func (ctx ppctx) fields(obj *otto.Object) []string {
var (
vals, methods []string
seen = make(map[string]bool)
)
add := func(k string) {
if seen[k] || boringKeys[k] {
return
}
seen[k] = true
if v, _ := obj.Get(k); v.IsFunction() {
methods = append(methods, k)
} else {
vals = append(vals, k)
}
}
iterOwnAndConstructorKeys(ctx.vm, obj, add)
sort.Strings(vals)
sort.Strings(methods)
return append(vals, methods...)
}
func iterOwnAndConstructorKeys(vm *otto.Otto, obj *otto.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 {
iterOwnKeys(vm, cp, func(prop string) {
if !seen[prop] {
f(prop)
}
})
}
}
func iterOwnKeys(vm *otto.Otto, obj *otto.Object, f func(string)) {
Object, _ := vm.Object("Object")
rv, _ := Object.Call("getOwnPropertyNames", obj.Value())
gv, _ := rv.Export()
switch gv := gv.(type) {
case []interface{}:
for _, v := range gv {
f(v.(string))
}
case []string:
for _, v := range gv {
f(v)
}
default:
panic(fmt.Errorf("Object.getOwnPropertyNames returned unexpected type %T", gv))
}
}
func (ctx ppctx) isBigNumber(v *otto.Object) bool {
BigNumber, err := ctx.vm.Run("BigNumber.prototype")
if err != nil {
panic(err)
}
cp := constructorPrototype(v)
return cp != nil && cp.Value() == BigNumber
}
func toString(obj *otto.Object) string {
s, _ := obj.Call("toString")
return s.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()
}
}
return nil
}
