Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Stencil Version

2.17.4

Current Behavior

Setting the value of a reflected property to undefined will cause Stencil to force the value to null instead.

Expected Behavior

I expect the value to be set to undefined.

Steps to Reproduce

1. Clone repo.
2. Run npm install.
3. Run npm run start.
4. Open dev tools. Observe that the fill property is logged as "outline".
5. Click the "Set fill to undefined" button. Observe that the property is logged as undefined and then logged again as null.
6. Remove reflect: true from the property decorator.
7. Click the "Set fill to undefined" button. Observe that the property is only logged as undefined.

Code Reproduction URL

https://github.com/liamdebeasi/stencil-reflect-prop

Additional Information

This was found in ionic-team/ionic-framework#25886.