bug: Popover backdrop not included in production builds #24129

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.

Ionic Framework Version

• v4.x
• v5.x
• v6.x

Current Behavior

In our Ionic React application, we are using the IonPopover component with the backdrop enabled.

When developing locally using npm run start, the popover opens and the backdrop is shown. Clicking outside of the popover closes it as expected.

However, when we deploy to our dev environment, the backdrop is not being shown, and the popover cannot be closed by clicking outside of it.

After some investigation, it appears that the IonBackdrop component is being marked as dead code during tree shaking, and not being included in the bundles created by npm run build.

Explicitly referencing the IonBackdrop somewhere in our code fixes the problem (i.e. console.log(IonBackdrop)).

Expected Behavior

After building and deploying the application, the backdrop should show and the user should be able to close the Popover by clicking outside of it.

Steps to Reproduce

1. Create a blank React Ionic v6 project
2. Add an IonButton and an IonPopover, with the button triggering the popover.
3. Build the application: npm run build
4. Run the application using a package such as serve
5. Click on the button
6. The popover shows without a backdrop

Code Reproduction URL

https://github.com/jvartanian/backdrop-tree-shaking

Ionic Info

Ionic:

Ionic CLI : 6.18.0 (~/.nvm/versions/node/v16.6.2/lib/node_modules/@ionic/cli)
Ionic Framework : @ionic/react 6.0.0-rc.1

Capacitor:

Capacitor CLI : 3.2.5
@capacitor/android : not installed
@capacitor/core : 3.2.5
@capacitor/ios : not installed

Utility:

cordova-res : not installed globally
native-run : 1.5.0

System:

NodeJS : v16.6.2 (/Users/justinvartanian/.nvm/versions/node/v16.6.2/bin/node)
npm : 7.20.3
OS : macOS Big Sur

Additional Information

No response