node.js - JavaScript Console -

i setup console in web browser using form fields. needs behave nodejs's repl (command line). in fact, using same api in both.

this falls-short because properties in context available under this. can please suggest tweak going? ideal if can keep context unchanged, use object loop (via object.keys(context)` , set properties on nodejs' repl context.

var context = {     debug: 'i debug' }  function evalincontext(js) {     return function() { return eval(js); }.call(context) }  //this not need work,  //confirms context under 'this' evalincontext('console.log(this.debug)') //prints 'i debug'  //this needs work:  try{     evalincontext('console.log(debug)')  }catch(e){     //not good: referenceerror: debug not defined     console.log(e) }  evalincontext('var a=2') try{     evalincontext('console.log(a)')  }catch(e){     //not good: referenceerror: not defined     console.log(e) } 

http://jsfiddle.net/hy8hewq4/

this in no way removes dangers of eval, can create string object evals var statement in function before evaling other piece of code.

in example below very important keys of variables valid identifier names , note values turned json protect them tampering across invocations, if want functions etc you'll have implement them own way

var variables = {     variables: undefined, // shadow self     debug: 'foo' };  function evalwithvariables(code) {     var key, variable_string = '';     (key in variables) {         variable_string += ', ' + key + ' = ' + json.stringify(variables[key]);     }     if (variable_string.length) eval('var' + variable_string.slice(1));     return eval(code); }  evalwithvariables('console.log(debug)'); // logs foo 

you may wish combine abstraction achieve own this (as you're doing)

you may wish put definition inside iife returns custom eval function protect references variables object, etc