1 files changed, 262 insertions, 0 deletions
diff --git a/internal/jsre/pretty.go b/internal/jsre/pretty.go
new file mode 100644
index 000000000..cf4bf2cf8
--- /dev/null
+++ b/internal/jsre/pretty.go
@@ -0,0 +1,262 @@
+// 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"
+	"io"
+	"sort"
+	"strconv"
+	"strings"
+
+	"github.com/fatih/color"
+	"github.com/robertkrimen/otto"
+)
+
+const (
+	maxPrettyPrintLevel = 3
+	indentString        = "  "
+)
+
+var (
+	FunctionColor = color.New(color.FgMagenta).SprintfFunc()
+	SpecialColor  = color.New(color.Bold).SprintfFunc()
+	NumberColor   = color.New(color.FgRed).SprintfFunc()
+	StringColor   = color.New(color.FgGreen).SprintfFunc()
+)
+
+// 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, w io.Writer) {
+	ppctx{vm: vm, w: w}.printValue(value, 0, false)
+}
+
+func prettyPrintJS(call otto.FunctionCall, w io.Writer) otto.Value {
+	for _, v := range call.ArgumentList {
+		prettyPrint(call.Otto, v, w)
+		fmt.Fprintln(w)
+	}
+	return otto.UndefinedValue()
+}
+
+type ppctx struct {
+	vm *otto.Otto
+	w  io.Writer
+}
+
+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():
+		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))
+	default:
+		fmt.Fprint(ctx.w, "<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.Fprintf(ctx.w, "[]")
+			return
+		}
+		if level > maxPrettyPrintLevel {
+			fmt.Fprint(ctx.w, "[...]")
+			return
+		}
+		fmt.Fprint(ctx.w, "[")
+		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.Fprintf(ctx.w, ", ")
+			}
+		}
+		fmt.Fprint(ctx.w, "]")
+
+	case "Object":
+		// Print values from bignumber.js as regular numbers.
+		if ctx.isBigNumber(obj) {
+			fmt.Fprint(ctx.w, NumberColor("%s", toString(obj)))
+			return
+		}
+		// Otherwise, print all fields indented, but stop if we're too deep.
+		keys := ctx.fields(obj)
+		if len(keys) == 0 {
+			fmt.Fprint(ctx.w, "{}")
+			return
+		}
+		if level > maxPrettyPrintLevel {
+			fmt.Fprint(ctx.w, "{...}")
+			return
+		}
+		fmt.Fprintln(ctx.w, "{")
+		for i, k := range keys {
+			v, _ := obj.Get(k)
+			fmt.Fprintf(ctx.w, "%s%s: ", ctx.indent(level+1), k)
+			ctx.printValue(v, level+1, false)
+			if i < len(keys)-1 {
+				fmt.Fprintf(ctx.w, ",")
+			}
+			fmt.Fprintln(ctx.w)
+		}
+		if inArray {
+			level--
+		}
+		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))
+		}
+
+	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())
+		} else {
+			fmt.Fprintf(ctx.w, "<%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] || strings.HasPrefix(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 {
+	// Handle numbers with custom constructor.
+	if v, _ := v.Get("constructor"); v.Object() != nil {
+		if strings.HasPrefix(toString(v.Object()), "function BigNumber") {
+			return true
+		}
+	}
+	// Handle default constructor.
+	BigNumber, _ := ctx.vm.Object("BigNumber.prototype")
+	if BigNumber == nil {
+		return false
+	}
+	bv, _ := BigNumber.Call("isPrototypeOf", v)
+	b, _ := bv.ToBoolean()
+	return b
+}
+
+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
+}