hasPath does not work if one attribute in the path is undefined

[sespinoza-dev]

hasPath does not work if one attribute in the path is undefined

If one of the object attributes in the path is undefined, hasPath throws an error. it should return false.

R.hasPath(['a', 'b'], { a: undefined });
=> TypeError: Cannot convert undefined or null to object
// expected false

[CrossEye]

This is definitely a bug. Are you interested in creating a PR?

[sespinoza-dev]

I'll give it a try.

Greettings!

[machad0]

Hi @sespinozj, are you still into this issue? If you don't, I'd like to try

cheers

[sespinoza-dev]

@machad0 do please go ahead. :)

[machad0]

Hi again,

Well, actually this bug was fixed at #2738, it's just an outdated bundle.

var hasPath = _curry2(function hasPath(_path, obj) {
...
  while (idx < _path.length) {
    if (_has(_path[idx], val)) {
      val = val[_path[idx]];
      idx += 1;
    } else {
      return false;
    }
 

the method doesn't contains the updated hasPath version, should we bump it?

[sespinoza-dev]

yes, thanks for checking that out @machad0

We use pathOr as a workaround in some cases thou.

Greetings!

[CrossEye]

Damn, I'm so caught up in what I want to do soon that I've forgotten what we've done recently!

[gouegd]

Just got bit by this bug, I don't think the fix is in the latest version (or it has come back):
R.hasPath(['a', 'b'], { a: undefined })
and
R.hasPath(['a', 'b'], { a: { b: undefined } })
both crash.

pathOr is a good workaround... unless you actually want to differentiate the case when a path exists with an undefined value, and the case where it does not exist.

[mattgrande]

@gouegd - First one fails for me, but the second one seems to work? (returns true as expected)

Edit: This is strange... It failed in the REPL for me, but I just pulled master, wrote a test that should fail, from what I can tell, and it's passing...

it('returns false for paths with undefined values', function() {
  eq(R.hasPath(['a', 'b'], { a: undefined }), false);
});

[gouegd]

@mattgrande That means the fix for #1 is on master but not published, doesn't it ?

[mattgrande]

That's what it seems like, yes.

[CrossEye]

I've been away from Ramda for a few weeks, and am trying to get back. I will try to publish again soon, and this change should then be included.

[gahabeen]

Seems like there is still an issue. If the sub value isn't an Object (Object or Array), it fails.

I ended up with this exact error message:

C:\[PATH]\ramda\src\internal\_has.js:2
  return Object.prototype.hasOwnProperty.call(obj, prop);
                                         ^
TypeError: Cannot convert undefined or null to object
    at hasOwnProperty (<anonymous>)
    at _has (C:\[PATH]\ramda\src\internal\_has.js:2:42)

Fixed it by simply checking if the value is indeed an object and can be checked against a sub property with && is(Object, val) as seen above in context.

// hasPath function
...
while (idx < _path.length) {
    if (!isNil(val) && is(Object, val) && _has(_path[idx], val)) {
      val = val[_path[idx]];
      idx += 1;
    } else {
      return false;
    }
  }
...

:)

[LorneCurrie]

Created a pull request #2825 for this issue

[PaulGrimshaw]

Is this going to be fixed? We are still getting this issue...

[gulsicka]

the issue still exists

[CrossEye]

@gulsicka: Can you demonstrate? It seems to be working correctly in my test.