Requiring tslib in transpiled code

[Luke Hodkinson]

Hi there! Firstly, thanks a tonne for this great utility and all your hard work, it's much appreciated.

I've been using Google's clasp to push TypeScript based Apps Scripts projects, and it was working as expected for a couple of weeks. Then recently I've found that the conversion from TypeScript has begun generating gas code that doesn't work. It seems that there is a line in the transpiled code as follows:

var tslib_1 = require("tslib");

This throws an error as require isn't supported. I can see that it seems to be related to using the following features (but not limited to them):

• async/await
• async generators
• rest operators

I did a little digging through my previous transpilations that worked, and I can see that in those instances the required polyfills from tslib were being injected into the transpiled code.

Do you have any thoughts on what may be happening here? Could it be an issue related to clasp and not ts2gas?

[PopGoesTheWza]

The fact that any tslib import/require show up in your code is an indication that there is something wrong in you typescript configuration. Most likely this is linked to the script engine you are targeting. By default, ts2gas use setup for the legacy Rhino engine. It is possible to setup your clasp project to target the newer V8 engine. I am unsure where it is properly documented, but you can check it here: google/clasp#735

Now my advice is to avoid using ts2gas altogether. Take a look at the project template below for a V8 engine, Typescript project where compilation is handled before invoking clasp

https://github.com/PopGoesTheWza/ts-gas-project-starter

Last, because of some issue with the owner of the @google/clasp npm package, the latest fixes and improvement are available through the forked-clasp npm releases:

npm uninstall -g @google/clasp
npm install -g forked-clasp

[Luke Hodkinson]

@PopGoesTheWza Thanks so much for your reply, that's incredibly helpful! You're correct, the issue was related to my tsconfig.json setup. I needed to modify the target and lib settings to ensure polyfills were injected.

Again, thanks for your response!