shadowDomCheck does not work in IE11

[jasperbosch]

Stencil version:

 @stencil/core@1.8.5

I'm submitting a:

[x] bug report
[ ] feature request
[ ] support request => Please do not submit support requests here, use one of these channels: https://stencil-worldwide.herokuapp.com/ or https://forum.ionicframework.com/

Current behavior:

IE 11 tries to execute .includes('[native') on undefined wich results in an error.

Expected behavior:

IE 11 should not get an error.

Steps to reproduce:

Try to open an Vue.js application that uses stencil-components in IE11.

Related code:

In src/client/client-windows.ts line 20:

export const supportsShadowDom = (BUILD.shadowDom) ? /*@__PURE__*/(() => (doc.head.attachShadow + '').includes('[native'))() : false;

however the doc.head.attachShadow is undefined in IE11

Other information:

Please revert 84b8e68

[adamdbradley]

Can you put together a repo case for this? Tests have been passing on ie11.

[jasperbosch]

Repo containing error: https://github.com/jasperbosch/jbo-vue-app
Repo containing component: https://github.com/jasperbosch/jbo-components

[adamdbradley]

Ok I see, thanks for the repo. In this case the app is not polyfilling includes before its first use. To keep it simple we can use indexOf to help out this scenario. We'll get it fixed in the 1.9.0 prerelease. Thanks