Support core-js@3.0.0

🚀 Feature request

core-js 3.0.0 is released, but ng serve fails with error

ERROR in ./node_modules/@angular-devkit/build-angular/src/angular-cli-files/models/jit-polyfills.js
Module not found: Error: Can't resolve 'core-js/es7/reflect' in 'C:\Work\frontend\node_modules\@angular-devkit\build-angular\src\angular-cli-files\models'

With core-js@3.0.0 it's import 'core-js/proposals/reflect-metadata';

Workaround: Add this to your tsconfig.json:

{
  "compilerOptions": {
    "paths": {
      "core-js/es7/reflect": ["node_modules/core-js/proposals/reflect-metadata"],
      "core-js/es6/*": ["node_modules/core-js/es/*"]
    }
  }
}

Command (mark with an x)

- [ ] new
- [x] build
- [x] serve
- [ ] test
- [ ] e2e
- [ ] generate
- [ ] add
- [ ] update
- [ ] lint
- [ ] xi18n
- [ ] run
- [ ] config
- [ ] help
- [ ] version
- [ ] doc

[DouglasOGarrido]

You can do that to resolve this issue: core-js Issue#412.

That configuration resolve this problem, but others appear, such as:
ERROR in ./src/polyfills.ts Module not found: Error: Can't resolve 'core-js/es6/array' ERROR in ./src/polyfills.ts Module not found: Error: Can't resolve 'core-js/es6/date'
and so on...

In the version 3.0.0 of core-js, there are many changes, including in the path of some folders and files.

[nicolo-ribaudo]

To fix this issue sooner, instead of upgrading to core-js@3 you just need to add core-js@2 to the dependencies of @angular-devkit/build-angular. Generally, it is a really bad practice to depend on a package which isn't neither in your dependendencies nor in your peerDependencies.

https://github.com/angular/angular-cli/blob/master/packages/angular_devkit/build_angular/package.json

Used at

angular-cli/packages/angular_devkit/build_angular/src/angular-cli-files/models/jit-polyfills.js

Line 8 in 0bb03d3

import 'core-js/es7/reflect';

[antonio25x]

Anyone working on Windows fix the issue mentioned here?
I applied the workaround but I still get the same error message

[antonio25x]

Nvm, I just had to add '../'