This uses the "Expand directories" feature introduces in Prettier 2.0 to automatically format all supported file types.
Also, I fixed some badly formatted files.
These changes aim to resolve most of the concerns raised in #15756. It adds missing polyfills for legacy browsers up until ES2019:
- Number.{parseFloat,parseInt}
- ~Math.{acosh,asinh,atanh,cbrt,clz32,cosh,expm1,fround,hypot,imul,log10p,log1p,log2,sign,sinh,tanh,trunc}~ _[Removed as these are [not widely used](https://github.com/vercel/next.js/pull/15772#discussion_r463957931)]_
- While these may seem to weigh a lot, they barely add 1 kB to the resulting bundle:
<img width="492" alt="gzip: 32 kB vs. 30.9 kB, Brotli: 28.8 kB vs. 27.8 kB" src="https://user-images.githubusercontent.com/14854048/89100961-1376e600-d3fc-11ea-90fd-3e6632b70220.png">
- ~Object.fromEntries~ _[Removed as [it's rarely used in user code](https://github.com/vercel/next.js/pull/15772#discussion_r463984612)]_
Also, the following features are now supported with build-time transforms:
- ~`globalThis` (gets transformed into `window` in browser environments)~ _[Removed as it [could break existing applications](https://github.com/vercel/next.js/pull/15772#discussion_r463956269)]_
- `export * as ns from 'module'`
The suggested TypeScript library version has been set to ES2018, so the features below become unavailable in type-checked files (they're not evenly supported by module-compatible browsers, either):
- Object.fromEntries
- String.prototype.matchAll
- String.prototype.replaceAll
- Promise.any + AggregateError
- WeakRef
As for the `import.meta` support, [webpack v5 seems to fix that](https://github.com/webpack/webpack/pull/11075), so it should eventually become an issue of the past.
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Fixes#15756
Fixes#4686
Adds tests for @zeit/next-typescript so that we don't regress on this again.
I've fixed an issue in the `next` CLI too which caused lingering processes when the process gets force killed, which is what we do in the test suite, so it kept running if there was no manual quit.
