Develop Reference

How to tune babel loader to properly import a module named macro.js when using CRA

I'm using a library vtk.js. VTK has a special design of classes (https://kitware.github.io/vtk-js/docs/develop_class.html). When I write a class I need to import macro.js module which exposes several base methods such as getters/setters/newInstance etc (https://github.com/Kitware/vtk-js/blob/master/Sources/macro.js).
Looks like CRA uses some special loader for macro.js files. I get an error when trying to import such a file (SyntaxError: Cannot use import statement outside a module). If I copy an original file macro.js from #kitware/vtk.js to my local source folder I still get an error. Even if I remove all the contents of macro.js file I get an error (The macro imported from "../macro" must be wrapped in "createMacro" which you can get from "babel-plugin-macros". Please refer to the documentation to see how to do this properly: https://github.com/kentcdodds/babel-plugin-macros/blob/master/other/docs/author.md#writing-a-macro). However, when I rename macro.js to macro2.js the error is gone.
Is there some way how can I disable this macro loader?

How to import typescript module from interactive console in intellij

I come from vanilla JavaScript, and I just don't get this. Usually I work directly from the interactive console in chrome or firefox and I can access all my resources to try them out manually.
Right now I have an Angular project with Intellij and I want to try out code inside a module. To be specific I'm busy implementing a queue pattern. So I made a Queue class.
When I type in the name of my class inside the javascript console, Intellij finds it as a suggestion. When I use their suggestion it inserts the import statement like import {Queue} from "./Queue";.
But when I try this it spews SyntaxError: Cannot use import statement outside a module. Which I understand, but how can I import the module from the console? (I figure that there is a compiled .js file somewhere, which I can import, right!?).

React added to existing webpage does not render components from multiple files

I want to add some functionality to my existing website with React.
I followed this tutorial. I came to a point where I wanted to separate classes from single js file to one for each class.
Then I used
import InputField from './InputField';
Which gave me this error:
Uncaught SyntaxError: Unexpected token import
When I imported my classes the same way in an example which was created via this tutorial, it worked perfectly.
I also tried with require(), but that gave me an error message saying that require() is not defined.
So how to divide classes from single file to multiple files on an existing website that has React as an addition? Am I forced to write all code in one file, if I just add React to website? I suspect, that it does not compile as it somehow should. (I am just starting with React)

You either have to use native ES modules or use a bundler like webpack or Rollup

What is the Purpose of Import Modules Without Export or Consumption within File

I have seen this following pattern within index.js file and I am left scratching my head. What would be the purpose of the following code below, considering:
The imported module is not being consumed within this module/file
There is no export of the imported module
The following code is all there is within the index.js file (yes, just one line):
import '../modules/index.js';
To elaborate, the index.js file is importing from '../modules/index.js'. That is it, there is no other code within the file whatsoever.

The only reason I'm aware of where one might want to do an import without utilizing anything imported is when the imported file has some form of side effect that happens simply by evaluating the code, such as defining a global variable. In this case, simply importing the code will cause that code to be run. If you can indicate more about the contents of modules/index.js we might be able to get to a more defined answer of what's happening in this case.

Angular2 - require module on client side

In the context of a Node.js / Express / Angular2 / typescript (IDE=Visual Studio) app, I am trying to load a third party .js utility (packery) onto the client side (for use in a directive). Someone made typescript definitions for it. The d.ts file looks like:
declare module "packery" {
interface PackeryOptions { stuff... }
class Packery { stuff .... }
export = Packery;
}
I refer to this d.ts file, tell the browser where the .js packery script lives, and then import the module as such:
import Packery = require('packery');
This compiles without complaint. However, upon running, the browser attempts (and fails) to find "packery" at http://localhost/packery as opposed to knowing packery is an imported library. This is in contrast to the other import statements I have made on the client such as:
import {Http, HTTP_PROVIDERS} from 'angular2/http';
which work - as far as I can tell the only two pieces of information I gave it for those were also a d.ts file and the location of the .js file, just like packery. But, I must be missing something. Have tried many combinations of file locations and linking and can't get it to work. How can I get the proper linking to "packery"?
Thanks!

I found a workaround for this and thought I'd post in case it helps anyone, although I am still having difficulty with the setup posed in the original question, that is, getting statements of the type:
import foo = require('foo')
to run on the CLIENT side. These work for me in node.js on the server, but on the client, for third party libraries that have been loaded via a script tag, I cannot get it to work, even if I add mapping entries to the system.js config file, irrespective of if I point to a .js file or a d.ts file.
Anyway, what does work is if you load the library using the script tag, then in your IDE put a reference path as such at the top of the CLIENT side code
/// <reference path="foo.d.ts" />
and ensure that your d.ts file does not declare a module/namespace but rather exports methods etc. directly. This lets the IDE compile without complaint, and the client side code is able to access the third party library.
However, I'm not sure if it is preferable / best practices to do what I did or if one should be configuring System.js somehow.

Typings are empty definitions of js libraries that aren't written in a typed language. They are only useful in development for IDEs hints and stuff, in your app, you'll still use the library as you normally would, adding the js file in your index.html or w/e you load your js files from.