github.com/LampardNguyen234/go-ethereum@v1.10.16-0.20220117140830-b6a3b0260724/internal/jsre/completion.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package jsre
    18  
    19  import (
    20  	"sort"
    21  	"strings"
    22  
    23  	"github.com/dop251/goja"
    24  )
    25  
    26  // CompleteKeywords returns potential continuations for the given line. Since line is
    27  // evaluated, callers need to make sure that evaluating line does not have side effects.
    28  func (jsre *JSRE) CompleteKeywords(line string) []string {
    29  	var results []string
    30  	jsre.Do(func(vm *goja.Runtime) {
    31  		results = getCompletions(vm, line)
    32  	})
    33  	return results
    34  }
    35  
    36  func getCompletions(vm *goja.Runtime, line string) (results []string) {
    37  	parts := strings.Split(line, ".")
    38  	if len(parts) == 0 {
    39  		return nil
    40  	}
    41  
    42  	// Find the right-most fully named object in the line. e.g. if line = "x.y.z"
    43  	// and "x.y" is an object, obj will reference "x.y".
    44  	obj := vm.GlobalObject()
    45  	for i := 0; i < len(parts)-1; i++ {
    46  		v := obj.Get(parts[i])
    47  		if v == nil || goja.IsNull(v) || goja.IsUndefined(v) {
    48  			return nil // No object was found
    49  		}
    50  		obj = v.ToObject(vm)
    51  	}
    52  
    53  	// Go over the keys of the object and retain the keys matching prefix.
    54  	// Example: if line = "x.y.z" and "x.y" exists and has keys "zebu", "zebra"
    55  	// and "platypus", then "x.y.zebu" and "x.y.zebra" will be added to results.
    56  	prefix := parts[len(parts)-1]
    57  	iterOwnAndConstructorKeys(vm, obj, func(k string) {
    58  		if strings.HasPrefix(k, prefix) {
    59  			if len(parts) == 1 {
    60  				results = append(results, k)
    61  			} else {
    62  				results = append(results, strings.Join(parts[:len(parts)-1], ".")+"."+k)
    63  			}
    64  		}
    65  	})
    66  
    67  	// Append opening parenthesis (for functions) or dot (for objects)
    68  	// if the line itself is the only completion.
    69  	if len(results) == 1 && results[0] == line {
    70  		obj := obj.Get(parts[len(parts)-1])
    71  		if obj != nil {
    72  			if _, isfunc := goja.AssertFunction(obj); isfunc {
    73  				results[0] += "("
    74  			} else {
    75  				results[0] += "."
    76  			}
    77  		}
    78  	}
    79  
    80  	sort.Strings(results)
    81  	return results
    82  }