Replace deprecated babel-eslint with new @babel/eslint-parser

[NullVoxPopuli]

This is mostly a tracking issue as I am not in a place to open a PR for this atm, but,

here in the app blueprint: https://github.com/ember-cli/ember-cli/blob/master/blueprints/app/files/package.json#L29
we're still using babel-eslint,
but, per, https://github.com/babel/babel-eslint, the eslint parser for babel has moved into their monorepo as https://github.com/babel/babel/tree/master/eslint/babel-eslint-parser

[SergeAstapov]

I would assume biggest show-stopper here is

@babel/eslint-parser requires @babel/core@>=7.2.0 and a valid Babel configuration file to run. If you do not have this already set up, please see the Babel Usage Guide.

because Ember CLI projects do not have dedicated Babel configuration file and may use ember-cli-babel@6.

[bmish]

I started an implementation in #9532:

• I think we can use requireConfigFile: false to avoid needing a Babel config file
• But I'm not sure what to do about the requirement for having @babel/core v7+ as a peer dependency since we don't include Babel as a dependency in the blueprint at all right now...

[tehhowch]

we don't include Babel as a dependency in the blueprint at all right now

Perhaps not explicitly, but the default blueprint adds it to new projects. It shouldn't be a surprise to users, either, as the Ember CLI intro explicitly states

Out of the box, your application will include:

• A development server.
• Template compilation.
• JavaScript and CSS minification.
• Modern features via Babel.

If one runs ember new my-app, the resulting package lockfile requires @babel/core due to embroider, broccoli-babel-transpiler, ember-auto-import, ember-cli, ember-cli-babel, and workerpool.

So moving it into package.json as a devDep or peerDep will just now be explicitly stating the dependency exists, rather than it being a transitive dependency.

[bmish]

@tehhowch great point! In fact, I just noticed that a bunch of other dependencies in a fresh Ember app already have an unmet peer dependency on @babel/core, so I think we can ignore this given that it's most certainly a transitive dependency (and I think ember-cli-babel is intended to be a wrapper around / manage the version of @babel/core anyway). CC: @rwjblue

warning "ember-resolver > babel-plugin-debug-macros@0.3.4" has unmet peer dependency "@babel/core@^7.0.0".
warning "ember-maybe-import-regenerator > ember-cli-babel > babel-plugin-debug-macros@0.2.0" has unmet peer dependency "@babel/core@^7.0.0-beta.42".
warning "ember-source > @babel/plugin-transform-block-scoping@7.14.1" has unmet peer dependency "@babel/core@^7.0.0-0".
warning "@glimmer/component > ember-cli-typescript > @babel/plugin-transform-typescript@7.5.5" has unmet peer dependency "@babel/core@^7.0.0-0".
warning "ember-data > @ember-data/private-build-infra > ember-cli-typescript > @babel/plugin-transform-typescript@7.8.7" has unmet peer dependency "@babel/core@^7.0.0-0".
warning "ember-load-initializers > ember-cli-typescript > @babel/plugin-transform-typescript@7.4.5" has unmet peer dependency "@babel/core@^7.0.0-0".
warning "ember-source > @babel/plugin-transform-object-assign@7.12.13" has unmet peer dependency "@babel/core@^7.0.0-0".

I have moved my PR #9532 into ready-for-review.

[ctjhoa]

Relates to emberjs/ember-cli-babel#366

[ctjhoa]

Another PR #9669