Tsdx: Make things async wherever possible

[jaredpalmer]

I noticed some sync file system tasks slipped into .10.x. We should make these async wherever possible.

Example: we should make this async https://github.com/jaredpalmer/tsdx/blob/76d7eb33e946c6dd3ebb656eabc874e392ecf012/src/index.ts#L476

[gndelia]

I would like to work on this one 😄

[gndelia]

Do I need to be formally assigned or should I start working on it directly?

[sw-yx]

go ahead!

[gndelia]

Hi
I have a draft PR, however I am having issues to commit - I am getting eslint errors under test/tests/lint - although that folder should be excluded. I get them even without my changes

I am running yarn lint (actually it is being run in the pre-commit hook)

$ yarn && yarn lint
yarn install v1.19.1
[1/4] Resolving packages...
success Already up-to-date.
$ tsc -p tsconfig.json
Done in 3.86s.
yarn run v1.19.1
$ yarn build && yarn lint:post-build
$ tsc -p tsconfig.json
$ node dist/index.js lint src test --ignore-pattern 'test/tests/lint'

C:\Users\DELL\Dev\Personal\tsdx\test\tests\lint\file-with-lint-errors.ts
  1:17  error  Parsing error: ',' expected

C:\Users\DELL\Dev\Personal\tsdx\test\tests\lint\file-with-prettier-lint-errors.ts
  1:18  error  Replace `·=·(···)·=>·⏎!!·('bar')⏎` with `=·()·=>·!!'bar'`  prettier/prettier
  4:1   error  Delete `⏎·`                                                prettier/prettier

C:\Users\DELL\Dev\Personal\tsdx\test\tests\lint\react-file-with-lint-errors.tsx
  4:9  error  Parsing error: Expression expected

✖ 4 problems (4 errors, 0 warnings)
  2 errors and 0 warnings potentially fixable with the `--fix` option.

Any ideas? My understanding is that those fields should be excluded from being analyzed

edit: nvm, I found the problem... windows 😆 I had to locally replace the single quotes for the path --ignore-pattern with escaped double quotes and it worked

(should I create an issue for that?)

[sw-yx]

@gndelia lets address those windows lint issues separately, and get this PR in as soon as you feel it is ready.

[sw-yx]

some progress made on these thanks to @gndelia!

[agilgur5]

See #291 . I did a bit on this with by using fs.pathExists from fs-extra instead of the old fs.existsSync, and some other things IIRC. But I think there's a tiny bit more left to fix that I'll get to soon too.