obj.hasOwnProperty is not a function about humps HOT 10 CLOSED

Are you able to give an example? Thanks.

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Example:

const myArr = [{
 validTill: 'date obj',
 eventId: 'uniq id'
}]

const decamelizeKeys = humps.decamelizeKeys(myArr); // Throws error obj.hasOwnProperty is not a function

// OR

const decamelizeKeys = _.map(myArr, (item) => humps.decamelizeKeys(item)); // Throws error obj.hasOwnProperty is not a function

Environment: Node 6

It works fine on browser.

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Sorry I am unable to reproduce this. I have tested the following in Node 6.9.3 and it works as expected:

> var humps = require('./')
undefined
> const myArr = [{
...  validTill: 'date obj',
...  eventId: 'uniq id'
... }]
undefined
> 
> const decamelizeKeys = humps.decamelizeKeys(myArr);
undefined
> decamelizeKeys
[ { valid_till: 'date obj', event_id: 'uniq id' } ]

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Hi,

I came across this issue too trying to run decamelizeKeys on the output object produced by the Joi validator. It turns out that the .hasOwnProperty method gets stripped by Joi.

Since we can't rely on supplied objects having the hasOwnProperty method (or a modified version) I have created a pull request to call hasOwnProperty directly from the Object prototype.

Lloyd

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Any chance of merging the fix and making a new release?

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I'm running into the same issue, but in the browser. The PR above seems to fix it.

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Any update on this? I'm running into this issue on the browser as well.

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obj.hasOwnProperty is a widely recognised method to check object properties, so I would like to understand why this is happening before merging. If anyone can provide a failing demo, I can look into it. Thanks.

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Yes, hasOwnProperty is the de facto way to check objects for properties, but unfortunately it's mutable so out in the wild it can't be relied on.

Here are a couple of examples of how you can't rely on the hasOwnProperty method of an object you haven't created.

const foo = Object.create(null);
foo; // {}
foo.bar = 'baz';
foo.hasOwnProperty('bar'); // TypeError: foo.hasOwnProperty is not a function

Object.prototype.hasOwnProperty.call(foo, 'bar'); // true

const foo2 = { bar: 'baz' };
foo2.hasOwnProperty = () => false;
foo2.hasOwnProperty('bar'); // false

Object.prototype.hasOwnProperty.call(foo2, 'bar'); // true

More info...

The comments above demonstrate this is more than just a hypothetical problem and I think that a library with no control over the objects that it receives should follow the principle:
Be conservative in what you do, be liberal in what you accept from others

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Perfect, thanks for the explanation! #36 has been merged and released in v2.0.1

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