Added support for .inspect() to return other objects

[tj]

not the greatest example but it's often useful to ignore some "private" properties or very large ones that are not really relevant.

function User(first, last) {
  this.first = first;
  this.last = last;
  this._id = 12345;
  this._role = 'admin';
  this.inspect = function(){
    return {
      first: first,
      last: last
    };
  };
}

function UserCollection() {
  var users = [];
  this.push = function(user){ users.push(user); };
  this.inspect = function(){ return users; };
}

var users = new UserCollection;
users.push(new User('tobi', 'ferret'));
users.push(new User('loki', 'ferret'));
users.push(new User('jane', 'ferret'));

console.log(users);

will output:

[ { first: 'tobi', last: 'ferret' },
  { first: 'loki', last: 'ferret' },
  { first: 'jane', last: 'ferret' } ]

I had added the constructor name like [User { first: 'tobi' }] etc but with [ all over the place it gets really difficult to read although I think that would be useful in general.

[bnoordhuis]

LGTM. One or two tests would be nice. Can another committer chime in?

[tj]

I'll add a different commit for this but I forgot to mention that I think console.dir() could be more like the browser and ignore .inspect() so that if you are the author of the library or just someone debugging you can bypass inspection and view the "raw" objects

[bnoordhuis]

You may want to open a separate issue for that. I don't have a strong opinion on the subject but others may.

[tj]

yup I will. If another committer is ok with this I'll add the tests

[koichik]

@visionmedia Sorry for the delay, LGTM. Please add the tests.

[ashb]

Does the hidden flag (which isn't passed along yet either mind, see #2443) and Object.defineProperties not already provide a way to do this:

function User(first, last) {
  this.first = first;
  this.last = last;
  this._id = 12345;
  this._role = 'admin';
  Object.defineProperties( this, {
    _id: { enumerable: false }
  , _role: { enumerable: false } 
  } );
}

Behaves like this

> console.log(new User('tobi', 'ferret'))
{ first: 'tobi', last: 'ferret' }
> console.log( require('util').inspect( new User('tobi', 'ferret'), true) )
{ last: 'ferret', [_role]: 'admin', [_id]: 12345, first: 'tobi' }

[TooTallNate]

I want this as well. The test from e859271 is good, but stringifying the result unconditionally doesn't make much sense. The behavior in this patch is much better in my opinion.

Currently:

$ node
> var o = { inspect: function () { return this } }
undefined
> o
[object Object]     <---- helpful never

[TooTallNate]

Oh, this needs a rebase and a test of its own though.