Use native `Object.assign` for shallow merges in Util.extend

[kamranayub]

Context

We have a utility, extend that supports deep merging. For shallow merges, however, it should use the new Object.assign native functionality (for perf/compatibility). Currently only IE11 is lacking it.

Proposal

Update Util.extend method to use Object.assign where available on shallow merges.

[PurityLake]

I'd be up for helping out with this if that's ok

[eonarheim]

@PurityLake All yours!

[eonarheim]

Assigning myself so no one takes it, let us know if you have questions.

[PurityLake]

Typescript doesn't seem to support it, sometimes requires polyfill.

Typescript issue

[kamranayub]

Just need to test for existence. If it exists then we use it, if not it does the current code path.

…

On Fri, Mar 24, 2017, 15:40 Robert ***@***.***> wrote: Typescript doesn't seem to support it, sometimes requires polyfill. Typescript issue <microsoft/TypeScript#3429> — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#763 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAiaa5POQBNoKtF_wZwYTEnvCM6Zv1Q7ks5rpCotgaJpZM4MjSmQ> .

[PurityLake]

@kamranayub the problem is that Object.assign is an ECMAScript2015 feature so Object.assign will stop the program from compiling when it is even mentioned.

[kamranayub]

I can try checking but all it needs is a type definition or can just be casted to the any type. (Object as any).assign

…

On Fri, Mar 24, 2017, 21:08 Robert ***@***.***> wrote: @kamranayub <https://github.com/kamranayub> the problem is that Object.assign is an ES2015 feature so Object.assign will stop the program from compiling when it is even mentioned. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#763 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAiaawEyPbA_gCNLYjpvO6e80qlZ3K0aks5rpHcSgaJpZM4MjSmQ> .

[PurityLake]

@kamranayub ah yes, sorry, that slipped my mind