Vfrdtyky

I'm trying to use rollup with babel but in output file I got duplicate definitions:

 var Projection =

  /*#__PURE__*/

  function () {

    /**

     * @param {Options} options Projection options.

     */

    function Projection(options) {

      _classCallCheck(this, Projection);



      /**

       * @private

       * @type {string}

       */

      this.code_ = options.code;

and

var Projection$1 = function Projection(options) {

    /**

     * @private

     * @type {string}

     */

    this.code_ = options.code;



    /**

     * Units of projected coordinates. When set to `TILE_PIXELS`, a

     * `this.extent_` and `this.worldExtent_` must be configured properly for each

     * tile.

     * @private

     * @type {module:ol/proj/Units}

     */

    this.units_ = /** @type {module:ol/proj/Units} */ (options.units);

My rollup config

// Rollup configuration for the full build



const path = require('path');

import noderesolve from 'rollup-plugin-node-resolve';

import commonjs from 'rollup-plugin-commonjs';

import {uglify} from 'rollup-plugin-uglify';

import sourcemaps from 'rollup-plugin-sourcemaps';

import babel from 'rollup-plugin-babel';

import alias from 'rollup-plugin-alias';

import minify from 'rollup-plugin-babel-minify';



const prod = process.env.BUILD === 'production';

const cesiumSource = 'node_modules/cesium/Source';

//const cesiumSource = 'Source/Cesium';

const olSource = 'ol_build/openlayers/src/ol';



const plugins = [

  noderesolve(),

  commonjs(),

];



// const uglifyPlugin = uglify({

    // compress: {

      // sequences: false, // workaround uglify bug with sequences

      // drop_console: true

    // }

  // });



const babelPlugin =  babel({

    babelrc: false,

    presets: [["@babel/preset-env", { modules: false }]],

    exclude: ['node_modules/**']

    // externalHelpers: true,

    // plugins: ["@babel/external-helpers"]

    // runtimeHelpers: true,

    // plugins: ["@babel/plugin-transform-runtime"]

});



const aliasPlugin = alias({

    ol: path.resolve(__dirname, olSource),

    Cesium: path.resolve(__dirname, cesiumSource)

  });



if (prod) {

  //plugins.push(uglifyPlugin);

  //plugins.push(minify);

}



plugins.push(babelPlugin);

plugins.push(aliasPlugin);

plugins.push(sourcemaps());



export default {

  input: './dist/index.js',

  output: [

    {file: prod ? './dist/ol.js' : './dist/ol-debug.js', format: 'iife', sourcemap: true}

  ],

  plugins

  //external: ['ol'],

};

and package.json config related to babel and rollup:

"devDependencies": {

    "@babel/core": "^7.1.2",

    "@babel/preset-env": "^7.1.0",

  "rollup": "0.65.2",

    "rollup-plugin-babel": "^4.0.3",

    "rollup-plugin-babel-minify": "^6.1.1",

    "rollup-plugin-commonjs": "9.1.6",

    "rollup-plugin-node-resolve": "3.4.0",

    "rollup-plugin-sourcemaps": "0.4.2",

    "rollup-plugin-uglify": "5.0.2",



 "dependencies": {

    "rollup-plugin-alias": "^1.4.0"

  }

When I use only rollup without babel in output file there is only 1 definition of "Projection".

Original class:

class Projection {



  /**

   * @param {Options} options Projection options.

   */

  constructor(options) {

    /**

     * @private

     * @type {string}

     */

    this.code_ = options.code;



    /**

     * Units of projected coordinates. When set to `TILE_PIXELS`, a

     * `this.extent_` and `this.worldExtent_` must be configured properly for each

     * tile.

     * @private

     * @type {import("./Units.js").default}

     */

    this.units_ = /** @type {import("./Units.js").default} */ (options.units);

I tried use previous version of babel for rollup and also tried use "external-helpers" plugin but still not work.

Rollup and babel are new for me.

Because of those duplicate definitions I got false when compare types with instanceof operator. Why there are duplicate definitions and how configure babel to get only one definition?