ES6 code is not bundle safe

[coryshaw]

Hello, This is a nice little utility! We noticed that it uses let and const (ES6) and is breaking our webpack build due to the fact that Uglify JS cannot minify ES6 code. Super easy to fork into our own function but just wanted to give a heads up. Thanks!

[mvayngrib]

@coryshaw as you're already using webpack, you can just configure it to transpile this module to es5. Use babel-loader and limit it to transpiling only this module either with include or test (test: /node_modules\/parse-usdl\/.*?\.js$/)

[nathany]

@mvayngrib I had some trouble getting the transpile to work. Should the parse-usdl library do the transpiling itself?

[nathany]

I'm not sure what it takes to get the library to transpile and work with projects that may not even use babel. For such a small library, my current solution for IE11 support is to remove the ES6 (from a fork).

[mvayngrib]

@nathany the problem with transpilation in-library is we don't know who our users are. IE11 users will want it transpiled a different way from people using chrome. I think it's better to delegate this decision to the consumer of this library, who will use some combination of webpack and babel-preset-env to create the bundle that works in their particular environment.

[nathany]

I'm not sure if there is a precedent from other libraries, but this is my first time running into this issue.

If the transpiled code isn't included, perhaps the solution is to provide better documentation in the README. As of yet, I haven't been able to get the transpiling working so that this library works in Internet Explorer 11 (yes, I know, why do we need to support IE 11 anyway, but we do).

[mvayngrib]

@nathany maybe I can help. What are you using to transpile the rest of your code? Babel with babel-preset-env + webpack is the standard these days, and they support transpiling per browser (including ie 11). Take a look at https://babeljs.io/docs/en/next/babel-preset-env.html

[mvayngrib]

i made a small example for you: https://github.com/mvayngrib/usdl-example

run: npm run build
open index.html (it will log a parsed usdl license to the console)
fiddle around with browser support in babel.config.js to see the differently transpiled code

edit: poking around, i see that usdl-example is not set up the ideal way. Webpack can invoke babel directly, see babel-loader

[nathany]

Okay. Will have to get back to you on this. Thanks.