How to include PostCSS in Create-React-App 2?

Question

css

Tell me please. I want to add a PostCSS nesting plugin to create-react-app 2 ( https://www.npmjs.com/package/postcss-nesting). I made an eject and added it to the webpack configuration. But inheritance doesn't work. Who dealt with PostCSS in CRA2, tell me what I did wrong? Or maybe there is a way to connect modules without eject?
The second day I google, but to no avail.

loader: require.resolve('postcss-loader'),
      options: {
        // Necessary for external CSS imports to work
        // https://github.com/facebook/create-react-app/issues/2677
        ident: 'postcss',
        plugins: () => [
          require('postcss-flexbugs-fixes'),
          require('postcss-preset-env')({
            autoprefixer: {
              flexbox: 'no-2009',
            },
            stage: 3,
          }),
          require('postcss-nesting'), // <------ Вот сюда добавил модуль
        ],

Answer 1

require('postcss-nesting')() - call the factory function that is returned from the module
// EDIT
What are you doing fooling us! :)
Read the specification first , and then invent non-existent CSS rules.

.SomeClass {
  &-foo { // < Такого в спецификации нет!
    
  }
}

.App {
  text-align: center;

  &.gg { // < работает 
    color: #1e90ff;
    }
}