Re: Reflect.hasOwn

> > On Sep 6, 2016, at 4:10 PM, Domenic Denicola wrote: > > Reflect is a namespace that contains the proxy traps (it’s a bit of an > unfortunate name), so we shouldn’t be adding things to it that are not part > of the meta-object protocol. I generally disagree with the idea

Re: Reflect.hasOwn

Just my 2 cents. The tiniest JS utility I know [1] solves verbosity and freeze the method so it's also safe. ```js // meet callerOf function callerOf(c) {return c.call.bind(c)} // how to use it const hasOwn = callerOf({}.hasOwnProperty); hasOwn({key: 'value'}, 'key'); // true hasOwn({value:

Re: Reflect.hasOwn

Removing hasOwnProperty from Object.prototype would break a lot of code, so it's not even an option, but we could at least add Object.hasOwn, since Reflect apparently isn't the right place for this (it's a shame, it would mirror nicely with Reflect.ownKeys). Doing this would improve a bit the

Re: Reflect.hasOwn

I'll admit I use them partially out of laziness and partially because engines already optimize for this much better than with actual maps (only string keys). I frequently alias `const hasOwn = Object.prototype.hasOwnProperty`, so this wouldn't do much for me other than saving a declaration in each

Re: Reflect.hasOwn

JSON.parse() and object literals are big sources of objects-as-maps. In both of these cases, using the `in` operator won't give the right answer. Le mar. 6 sept. 2016 à 22:11, Domenic Denicola a écrit : > Reflect is a namespace that contains the proxy traps (it’s a bit of an >

RE: Reflect.hasOwn

Reflect is a namespace that contains the proxy traps (it’s a bit of an unfortunate name), so we shouldn’t be adding things to it that are not part of the meta-object protocol. A new namespace, or using Object, might be OK. I think that it will still be controversial, since this proposal is in

Re: Reflect.hasOwn() ?

2014-07-27 18:14 GMT+02:00 Mark S. Miller erig...@google.com: Although there is some interesting work in trying to obtain security relevant guarantees from a script that isn't first, where a malicious script may instead have been first (link please if anyone has it), this work did not seem

Re: Reflect.hasOwn() ?

On Sat, Jul 26, 2014 at 5:14 PM, Mark S. Miller erig...@google.com wrote: Hi Peter, what is the security issue you are concerned about? Unless `Reflect` is completely sealed out of the box, you can never know whether properties on it are the actual built-ins. That's all. - peter

Re: Reflect.hasOwn() ?

Le 27/07/2014 13:35, Peter van der Zee a écrit : On Sat, Jul 26, 2014 at 5:14 PM, Mark S. Miller erig...@google.com wrote: Hi Peter, what is the security issue you are concerned about? Unless `Reflect` is completely sealed out of the box, you can never know whether properties on it are the

Re: Reflect.hasOwn() ?

On Sun, Jul 27, 2014 at 1:57 PM, David Bruant bruan...@gmail.com wrote: You can deeply freeze it yourself before any other script accesses it. That's already assuming you are first. You may not be without your knowledge (ISP injection, virus hijack, garden gnomes, etc). At this point you'll be

Re: Reflect.hasOwn() ?

Although there is some interesting work in trying to obtain security relevant guarantees from a script that isn't first, where a malicious script may instead have been first (link please if anyone has it), this work did not seem practical to me. My POV: A realm starts out pervasively malleable.

Re: Reflect.hasOwn() ?

On Sun, Jul 27, 2014 at 6:14 PM, Mark S. Miller erig...@google.com wrote: Although there is some interesting work in trying to obtain security relevant guarantees from a script that isn't first, where a malicious script may instead have been first (link please if anyone has it), this work did

Re: Reflect.hasOwn() ?

On Sunday, July 27, 2014, Tab Atkins Jr. jackalm...@gmail.com wrote: On Sat, Jul 26, 2014 at 11:36 AM, Kevin Smith zenpars...@gmail.com javascript:; wrote: * As far as I can tell, `hasOwnProperty` is mainly used to implement maps via objects. `Map` will eliminate this use case. To a

Re: Reflect.hasOwn() ?

`obj.hasOwnProperty('foo')` fails with objects that do not inherit from `Object.prototype` I'd personally +1 `Reflect.hasOwnProperty(genericObject, propertyName)` without going fancy with shortcuts if the meaning and the result should be exactly the same as

Re: Reflect.hasOwn() ?

2014-07-26 5:43 GMT+02:00 Axel Rauschmayer a...@rauschma.de: ECMAScript 6 mostly eliminates the need to call methods generically (no need to use the array-like `arguments`, `Array.from()`, spread operator, etc.). The only exception that comes to my mind is `{}.hasOwnProperty.call(obj, key)`

Re: Reflect.hasOwn() ?

The rationale to remove Reflect.hasOwn was that it could easily be simulated via (Reflect.getOwnPropertyDescriptor(obj,name) !== undefined). While this conses a throw-away property descriptor object, the overhead was deemed insignificant. Sounds good. Still, hanging hasOwnProperty off of

Re: Reflect.hasOwn() ?

On Fri, Jul 25, 2014 at 9:02 PM, Peter van der Zee e...@qfox.nl wrote: On Sat, Jul 26, 2014 at 5:43 AM, Axel Rauschmayer a...@rauschma.de wrote: The only exception that comes to my mind is `{}.hasOwnProperty.call(obj, key)` (which is the only safe way to invoke this method). Would it make

Re: Reflect.hasOwn() ?

why would you drop the specificity of the name? would a Symbol be a valid second argument ? and what if one day we'd like to introduce a hasOwnValue instead, as similar to Array#contains but for generic objects ? Regards On Sat, Jul 26, 2014 at 5:52 AM, Kevin Smith zenpars...@gmail.com wrote:

Re: Reflect.hasOwn() ?

Overall, I'm leaning towards keeping the built-in Reflect API minimal. There's room for many more utility methods (Reflect.getPropertyDescriptors comes to mind) which can all be expressed as a library. After thinking about it some more, I agree w.r.t. these two examples: * As far as I can

Re: Reflect.hasOwn() ?

* As far as I can tell, `hasOwnProperty` is mainly used to implement maps via objects. `Map` will eliminate this use case. To a certain extent yes, but not completely. Objects-as-maps will still be used quite frequently as object literals passed into functions (as an options object, for

Re: Reflect.hasOwn() ?

On Jul 26, 2014, at 20:36 , Kevin Smith zenpars...@gmail.com wrote: * As far as I can tell, `hasOwnProperty` is mainly used to implement maps via objects. `Map` will eliminate this use case. To a certain extent yes, but not completely. Objects-as-maps will still be used quite frequently

Re: Reflect.hasOwn() ?

Did you mean `Reflect.ownKeys()`? I meant Object.keys. That will eliminate the inconsistency between Object.keys usage and hasOwnProperty usage that crops up sometimes: https://github.com/joyent/node/issues/7587 When dealing with objects-as-maps, it's usually just the key-ness that you're

Re: Reflect.hasOwn() ?

I meant Object.keys. That will eliminate the inconsistency between Object.keys usage and hasOwnProperty usage that crops up sometimes: Nevermind. Brain-stall. Sorry about the noise. ___ es-discuss mailing list es-discuss@mozilla.org

Re: Reflect.hasOwn() ?

On 7/26/14, 5:33 AM, Tom Van Cutsem wrote: The rationale to remove Reflect.hasOwn was that it could easily be simulated via (Reflect.getOwnPropertyDescriptor(obj,name) !== undefined). While this conses a throw-away property descriptor object, the overhead was deemed insignificant. That depends

Re: Reflect.hasOwn() ?

On Sat, Jul 26, 2014 at 5:43 AM, Axel Rauschmayer a...@rauschma.de wrote: The only exception that comes to my mind is `{}.hasOwnProperty.call(obj, key)` (which is the only safe way to invoke this method). Would it make sense to provide that as a tool function, e.g. as `Reflect.hasOwn()`? That

Re: Reflect.hasOwn() ?

On Jul 26, 2014, at 6:02 , Peter van der Zee e...@qfox.nl wrote: On Sat, Jul 26, 2014 at 5:43 AM, Axel Rauschmayer a...@rauschma.de wrote: The only exception that comes to my mind is `{}.hasOwnProperty.call(obj, key)` (which is the only safe way to invoke this method). Would it make sense to