Undefined variables/properties don't error with Vue Composition API in Vue 2

[nsnyder]

• [x] I have searched through existing issues
• [x] I have read through docs
• [x] I have read FAQ

Info

• Platform: macOS Catalina
• Vetur version: 0.24.0
• VS Code version: 1.44.2

Problem

When I'm using the Vue Composition API plugin in Vue 2, Vetur doesn't surface errors for undefined properties. As demonstrated, this is not an issue with the Options Style version.

Browser output:

VS Code window (split to demonstrate the difference between styles):

Reproducible Case

https://github.com/nsnyder/typescript-sandbox/tree/demonstrate-vetur-issues Clone and run npm install then checkout the demonstrate-vetur-issues branch.

Please let me know how I can help. Vetur is a great tool to help me write better code! Thanks for everything you put into this!

[rfox12]

This frustrated me to no end. I've literally spent the last two days working on dev environment setup (but hopefully almost there).

This particular issue is most likely related to this: https://github.com/vuejs/vetur/issues/1509

So the hack-workaround for now: ensure all your Composition API setup functions have props. Once you add a props object then you'll notice Vetur's nice problem detection kicks in again.

[nsnyder]

@rfox12 Thank you! A workaround, to be sure, but one that'll give me a little extra peace-of-mind as I do my day-to-day coding until it's fixed.

[myknbani]

I can confirm that adding an empty props would bring back the red squigglies.