Resolve require Calls for browser output in Babel

Question

I want to transform ES6 to ES5 for browser usage (IE). Since I need some polyfills, "useBuiltIns": "usage" was set.

{
  "sourceType": "script",
  "ignore": ["gulpfile.js"],
  "presets": [
    ["@babel/preset-env", 
      { "useBuiltIns": "usage" }
    ]
  ]
}

But the output file contains require statements at the beginning:

require("core-js/modules/es7.promise.finally");
require("core-js/modules/es6.function.name");
require("core-js/modules/es6.weak-map");
// ...

Why doesn't embed Babel 7 those files? As I understood the documentation of sourceType, we have script for browser usage, so that I get simply a single bundled file without any modules.

Answer 1

I ended using browserify with Babbel plugin in my gulp task:

const gulp = require("gulp"),
  babel = require("gulp-babel"),
  browserify = require("browserify"),
  fs = require("fs");

gulp.task("js", () => {
  let outputFolder = 'dist'
  let targetFile = "customization.js"
  const js = "src/js"
  let jsSources = [`${js}/polyfills.js`, `${js}/custom.js`]

  return browserify(jsSources)
    .transform("babelify")
    .bundle()
    .pipe(fs.createWriteStream(`${outputFolder}/js/${targetFile}`))
})

This will create a single bundle without any module loaders.