Browserify - ParseError: 'import' and 'export' may appear only with 'sourceType: module

Question

In my gulpfile I have

var gulp = require(\'gulp\');
var browserSync = require(\'browser-sync\').create();
var sass = require(\'gulp-sass\');
var babel = requ         


        

Answer 1

Browserify in Gulp

For those who work with gulp and want to transpile ES6 to ES5 with browserify, you might stumble upon gulp-browserify plug-in. Warning as it is from version 0.5.1 gulp-browserify is no longer suported!!!. Consequences, of this action and transpiling with gulp-browserify will result with source code that might produce errors such as the one in question or similar to these: Uncaught ReferenceError: require is not defined or Uncaught SyntaxError: Unexpected identifier next to your import statements e.g. import * from './modules/bar.es6.js';

Solution

Althoutg gulp-browserify recomends to "checkout the recipes by gulp team for reference on using browserify with gulp". I found this advice to no avail. As it is now (2st July 2019) solution that worked for me was to replace gulp-browserify with gulp-bro@1.0.3 plug-in. This successfully, transpired ES6 to ES5 (as it is now) - It might change in future since support for JavaSript libraries decays with time of it appearance.

Assumption: To reproduce this solution you should have installed docker. Beside that you should be familiar with babel and babelify.

Source Code

This solution was successfully reproduced in docker environment, run node:11.7.0-alpine image.

Project Structure

/src                          <- directory
/src/app/foo.es6.js
/src/app/modules/bar.es6.js
/src/app/dist                 <- directory
/src/app/dist/app.es5.js
/src/gulpfile.js
/src/.babelrc
/src/package.json
/src/node_modules             <- directory

Step 1: Run docker image

$ docker run --rm -it --name bro_demo node:11.7.0-alpine ash

Step 2: Create directories and source files

$ mkdir -p /src/dist
$ mkdir -p /src/app/modules/
$ touch /src/app/foo.es6.js
$ touch /src/app/modules/bar.es6.js
$ touch /src/gulpfile.js
$ touch /src/.babelrc
$ touch /src/package.json
$ cd /src/

$ apk add vim

.babelrc

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

package.json

{
  "name": "src",
  "version": "1.0.0",
  "description": "",
  "main": "",
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/core": "^7.4.5",
    "@babel/preset-env": "^7.4.5",
    "babelify": "^10.0.0",
    "gulp": "^4.0.2",
    "gulp-bro": "^1.0.3",
    "gulp-rename": "^1.2.2"
  }
}

bar.es6.js

"use strict"

class Bar {
  constructor(grammar) {
    console.log('Bar time!');
  }
}

export default Bar;

foo.es6.js

"use strict"

import Bar from './modules/bar.es6.js';

class Foo {
  constructor(grammar) {
    console.log('Foo time!');
  }
}

var foo = new Foo()
var bar = new Bar()

gulpfile.js

const bro = require('gulp-bro');
const gulp = require('gulp');
const rename = require('gulp-rename');
const babelify = require('babelify');

function transpileResources(callback) {
  gulp.src(['./app/foo.es6.js'])
    .pipe(bro({transform: [babelify.configure({ presets: ['@babel/preset-env'] })] }))
    .pipe(rename('app.es5.js'))
    .pipe(gulp.dest('./dist/'));

  callback();
}

exports.transpile = transpileResources;

Step 3 - Transpile ES6 to ES5

$ npm install
$ npm install -g gulp@4.0.2

$ gulp transpile
[09:30:30] Using gulpfile /src/gulpfile.js
[09:30:30] Starting 'transpile'...
[09:30:30] Finished 'transpile' after 9.33 ms

$ node dist/app.es5.js
Foo time!
Bar time!

Source code after transpilation app.es5.js

(function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i