In some cases unexpected files may be provided which can cause to unsupported or broken behaviour.
One such use-case is users can provide TypeScript files as `scripts` input, this would not be processed by the TypeScript compiler, see: https://github.com/angular/angular-cli/issues/17125 and would cause the build to fail with a an unhelpful error message during optimization as the JS optimizers cannot parse TypeScript input.
BREAKING CHANGE:
`browser` and `karma` builders `script` and `styles` options input files extensions are now validated.
Valid extensions for `scripts` are:
- `.js`
- `.cjs`
- `.mjs`
- `.jsx`
- `.cjsx`
- `.mjsx`
Valid extensions for `styles` are:
- `.css`
- `.less`
- `.sass`
- `.scss`
- `.styl`