Removing development files from bundle

bundle.js

// load() call is removed, but import remains there

!function(modules) {
    function __webpack_require__(moduleId) {
        if (installedModules[moduleId]) return installedModules[moduleId].exports;
        var module = installedModules[moduleId] = {
            i: moduleId,
            l: !1,
            exports: {}
        };
        return modules[moduleId].call(module.exports, module, module.exports, __webpack_require__), 
        module.l = !0, module.exports;
    }
    var installedModules = {};
    __webpack_require__.m = modules, __webpack_require__.c = installedModules, __webpack_require__.d = function(exports, name, getter) {
        __webpack_require__.o(exports, name) || Object.defineProperty(exports, name, {
            configurable: !1,
            enumerable: !0,
            get: getter
        });
    }, __webpack_require__.n = function(module) {
        var getter = module && module.__esModule ? function() {
            return module.default;
        } : function() {
            return module;
        };
        return __webpack_require__.d(getter, "a", getter), getter;
    }, __webpack_require__.o = function(object, property) {
        return Object.prototype.hasOwnProperty.call(object, property);
    }, __webpack_require__.p = "", __webpack_require__(__webpack_require__.s = "./test.js");
}({
    "./test.js": function(module, __webpack_exports__, __webpack_require__) {
        "use strict";
        Object.defineProperty(__webpack_exports__, "__esModule", {
            value: !0
        }), __webpack_require__.d(__webpack_exports__, "main", function() {
            return main;
        });
        var main = (__webpack_require__("./very.large.js"), function() {
        });
    },
    "./very.large.js": function(module, __webpack_exports__, __webpack_require__) {
        "use strict";
        __webpack_exports__.a = function() {
            return "VERY LARGE";
        };
    }
});

output.txt

Hash: 829e853f6a502b8cc064
Version: webpack 3.0.0
Time: 3809ms
    Asset       Size  Chunks             Chunk Names
./test.js  722 bytes       0  [emitted]  test
[./test.js] ./test.js 174 bytes {0} [built]
[./very.large.js] ./very.large.js 56 bytes {0} [built]

WARNING in ./test.js from UglifyJs
Dropping __PURE__ call [./test.js:81,24]
Dropping side-effect-free statement [./test.js:80,2]
Side effects in initialization of unused variable __WEBPACK_IMPORTED_MODULE_0__very_large__ [./test.js:74,25]

test.js

// This import should be dropped in production,
// because it's very large and contains development data 
// (like locales for all languages).
import load from './very.large'

export const main = () => {
  let data = {}
  
  if (process.env.NODE_ENV !== 'development') {
    data = /*#__PURE__*/load()
  }
}

very.large.js

export default () => 'VERY LARGE'