prefer-object-spread should discuss spec availability

[vapier]

the prefer-spread page helpfully discusses the fact that it's new to ES2015, but there is no such info on the prefer-object-spread page which makes it read like people should be able to readily use it.

unfortunately, it's new to ES2018, and even then, going by the MDN page, Edge & Safari don't yet support it.

[ljharb]

These days, most people are using Babel, so browser support is irrelevant.

It'd still be useful to make the docs clearer, tho!

[ilyavolodin]

@ljharb That's a very generic statement and one, that I believe is totally false. There's a huge number of legacy sites that are still supported that do not use Babel, so browser support is very much relevant. It's better to say that in your experience it's irrelevant.

[ljharb]

@ilyavolodin i should have qualified; irrelevant for those users. I’m curious where your data comes from about the large number of legacy sites that use updated eslint but don’t use Babel, but we can discuss that in a different medium :-)

[ilyavolodin]

i should have qualified; irrelevant for those users

That's also a very broad statement. Most of the sites have a matrix of supported browsers. If they do not transpile their code, they have to write code that will run natively in those browsers, which includes understanding of which features are supported and which are not.
If you work for a modern company and are heavily involved in Open Source, it's really easy to think that everyone is writing modern WebApps and using Babel, Webpack, React and other popular tools. But in reality, that covers a rather small percentage of JS developers. I know, because I work with those developers every day.

[platinumazure]

Putting aside the discussion about what browsers people can support and whether or not some products use transpiling for the moment...

I think we can agree that we would welcome any clarity around which version of the ECMAScript specification introduces a feature such as object spread in our documentation. @vapier Would you like to submit a pull request?

[nzakas]

👍 At a minimum, this should be mentioned in "When Not to Use It".

[vapier]

i started off by throwing up #11137 to get a sense of the process. i can try cribbing the style from other pages once that goes through.

i agree that babel or any other tooling is irrelevant to the discussion. many other eslint pages discuss standards availability. fwiw, i use eslint, but have zero interest in anything like babel.