Make compatible with `--isolatedModules` TypeScript flag

[rivertam]

Describe the bug

When doing nothing but importing the project as such:

import Unity, { UnityContent } from 'react-unity-webgl';

TypeScript with the isolatedModules flag gives the error:

Type error: Cannot re-export a type when the '--isolatedModules' flag is pr
ovided.  TS1205

    4 | import { UnityVersion } from "./enums/UnityVersion";
    5 |
  > 6 | export { IUnityConfig, UnityContent, UnityVersion };
      |          ^
    7 | export default Unity;
    8 |

To Reproduce
I can make detailed reproduction steps, but I don't think it's necessary in this instance.

Expected behavior
I expect at least for it to build. =)

Desktop (please complete the following information):

• OS: Linux
• Browser: N/A (Node @ 10.2.1, TypeScript @ 3.2.2)
• Version: 7.07 on npm

Additional context
Hello! I know this is not truly a bug, but Create React App with the default TypeScript options actually does not seem to allow you to turn this flag off, so this module is unusable in CRA with TypeScript. It's not that big of a deal, but I suspect it's a quick fix. I will look into fixing it myself.

[rivertam]

I tried to fix this, but more issues popped up. It seems much of this library is non-compatible with Babel 7's built in TypeScript transpiler. I no longer know if it's a good idea to make it compatible. For now, I'm going to do without the TypeScript portions, but this may very well be a common problem going forward for users of CRA. I don't know how you're supposed to do a lot of this, and it seems like TS's isolatedModules flag might be poorly implemented.

[jeffreylanters]

Thanks for your report @rivertam! I've looked into it, and there was no need to export the interface anyway. I removed it from the index exporter. Could you try if this fixes your issue? See release version 7.0.8.

[rivertam]

Hey @jeffreylanters, I really appreciate your time on this. Unfortunately, there's still an issue:

Type error: Cannot compile namespaces when the '--isolatedModules' flag is provided.  TS1208

  > 1 | declare class UnityLoader {
      | ^
    2 |   constructor();
    3 |
    4 |   /**

I've created a minimal viable reproduction so you can test for yourself if you'd like to:

https://github.com/rivertam/react-unity-webgl-issue-mvr

[jeffreylanters]

Hey @rivertam. Thanks for the mvr! I will look into this, I have to say I don't really know what the use of the isolated modules compiler option is. I see here that the options is turned off by default, when using the official Typescript compiler. I'll keep you up-dated! If you manage to find a fix for this issue before I do, feel free to create a pull request.

[rivertam]

@jeffreylanters Yep, I can't answer that either. I just know that the TS compiler that comes with babel 7 doesn't support the option being off, or at least that's what I hear when trying to figure out why Create React App's built in TypeScript has the option on.

If I had to guess, compiling each module separately allows Babel to run TS anywhere in the plugin chain. I really don't understand how to solve it, though. It almost seems like a completely different language at that point.

[jeffreylanters]

@rivertam Is Created React App for TypeScript packed with a Babel loader? Odd, why would you need Babel if you’re using TypeScript. I just plug the TypeScript loader directly into my WebPack config. I’ll look into it.

[rivertam]

@jeffreylanters Babel 7 I believe natively supports TS. This is better explained I think by the relevant issues.

facebook/create-react-app#4146 here's one

https://blogs.msdn.microsoft.com/typescript/2018/08/27/typescript-and-babel-7/ here's one from the TypeScript team (I think)

I agree, I think it would probably be better to just use TypeScript to do the transpilation rather than Babel. It seems like you need TS to do the type checking anyways.

[github-actions]

This issue is stale because it has been open for 30 days with no activity.