console.timeEnd('hasOwnProperty') fails hilariously

[pluma]

Because the timers are currently stored as named properties of an object, timers with funny labels will result in console.timeEnd dutifully logging NaNms.

This affects hasOwnProperty, __proto__ and likely anything else that lives on Object.prototype.

A solution would be using ES6 symbols when they land in node.

A workaround would be prefixing the property names with some arbitrary string (except _, which would re-create the problem for timers labelled _proto__) instead of using the label verbatim.

[dougwilson]

Does changing the line at https://github.com/joyent/node/blob/master/lib/console.js#L43 to prop.value = Object.create(null) fix it?

[pluma]

Nope, because even Object.create(null) has the magical __proto__:

var x = Object.create(null);
x.__proto__ = 'lol';
console.log(x.__proto__); // null

[dougwilson]

Sure, but at most, all you'll get is Error: No such label: __proto__. Everything else seems to work fine besides that, right?

[pluma]

Yes, that should work with that caveat.

[cjihrig]

I have verified that this can be solved with Object.create(null). I'll submit a patch.

[pluma]

Indeed. The __proto__ issue seems to be absent in newer versions of V8 (as in io.js).

[cjihrig]

Fixed in 6c3647c

[misterdjules]

@cjihrig Do we want to leave this issue open, or open another issue to fix this in v0.10?

[cjihrig]

@misterdjules I don't think there is a really clean fix for 0.10. I would say either leave as is with the existing few edge cases, or apply this patch, which would leave __proto__ as the only edge case.

[misterdjules]

@cjihrig We could use a different data structure for _times to store times. For instance, it could be an array of { label: 'someLabel', time: Date.now() }.

I have never used console.time and console.timeEnd before. As a result, I'm not aware of its uses cases and I'm not sure how such a change would impact performance.

What do you think?

[cjihrig]

@misterdjules I think that solution would work. The slight performance hit should be fine since it's a console operation. However, a similar problem exists with event names, and I wouldn't recommend this approach in that code.

I would move the Date.now() call in timeEnd() before the call to findTimeWithLabel() so that you aren't timing the array search.

[misterdjules]

@cjihrig Good point, thank you! Created #9215.

[misterdjules]

Fixed in v0.10 by c8239c0.