Importing via import/export "pass-through" causes randomly undefined variables (TypeScript)

Version

3.0.0

Reproduction link

https://github.com/ffxsam/repro-undefined-import

Node and OS info

yarn 1.9.4, Ubuntu 18.04

Steps to reproduce

1. Clone and run yarn
2. yarn serve
3. Open Chrome console, note that routes is undefined

What is expected?

routes should be an array of routes

What is actually happening?

routes is undefined

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Of note is this line in the code: https://github.com/ffxsam/repro-undefined-import/blob/master/src/components/LoginForm.vue#L100

Edit that and replace routeNames.DASHBOARD with any arbitrary string, and save. Now you’ll see that routes in the console is an array. Also updating the import to the following will fix it:

import { routeNames } from '../router/route-names';

This is very strange and took me hours to track down. It may or may not be a vue-cli issue, but I figured this was a good starting point. Sorry I don’t have a more descriptive issue report, but it’s so random, I’m not even sure how to describe it.

[sodatea]

Finally figured out… It’s due to a circular dependency here: https://github.com/ffxsam/repro-undefined-import/blob/a1b19fd90439f95bf218fda5edcff60065897864/src/router/routes/index.ts#L6

[ffxsam]

That’s the tough thing here, determining where the issue actually lies (webpack? TypeScript?). I don’t think there’s an immediate solution for this, so I’ll have to remain conscious of imports/re-exports.

Thanks for your help!

PS: Made the repo private, there was a bit more code in there that was I comfortable with. Not that there was anything terribly proprietary, but still. 😄