Module imports generated by other Babel plugins are ignored

[Jens Maier]

When configured to do so, @babel/preset-env can emit import or require statements at the top of each transpiled file to provide exactly those polyfills the code requires.

Example:

export default class Example {
  buildMap() { return new Map().set("foo", "bar") }
}

Babel options:

let babelOptions = {
  plugins: ["@babel/proposal-class-properties"],
  presets: [
    ["@babel/env", {
      targets: {
        chrome: "64",
        firefox: "58",
        ie: "11"
      },
      modules: false,
      useBuiltIns: "usage"
    }],
    ["transform-ui5", {
      autoConvertControllerClass: false,
      moveControllerPropsToOnInit: true
    }]
  ]
}

(Note: useBuiltIns: "usage" is an experimental feature of @babel/preset-env.)

Result:

import "core-js/modules/web.dom.iterable";
import "core-js/modules/es6.array.iterator";
import "core-js/modules/es6.string.iterator";
import "core-js/modules/es6.map";

// ...

sap.ui.define([], function () {
  // ...
});

I have tried to reorder the "@babel/env" and "transform-ui5" presets in my Babel configuration, but babel-plugin-transform-modules-ui5 appears to be unable to transform the imports generated by other plugins.

[Ryan Murphy]

I've started to fix this on branch fix/move-module-transform-out-of-program-enter-visitor. It's a pretty big change that I've been putting off for awhile. The unit tests are all good and I spot checked it in my example app, but I need to check it against some real world apps.

[Jens Maier]

How far along is that branch? I could run some tests with the app we're building right now (can't release the sources, unfortunately 🙁), but it'll take a few days...

[Ryan Murphy]

Testing of this went well so I pushed it as v7.0.0.rc6.
v7 release coming soon. I just want to get all the options where I think makes sense.