fix(global): Only cascade mode from parent *Ionic* components

[jakobe]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue Number: Fixes #20055

Wrapping an Ionic component in a non-Ionic element with a mode attribute throws error:

<p mode="foo">
  <ion-label></ion-label>
</p>

What is the new behavior?

Only apply the Ionic mode from Ionic ancestors.

Does this introduce a breaking change?

• Yes
• No

Other information

[brandyscarney]

Tested using dev build 5.1.0-dev.202003251635.54463b4

This is the expected behavior, with this PR:

Warning on foo, falls back to default mode:

<ion-toggle mode="ios"></ion-toggle>
<ion-toggle mode="md"></ion-toggle>
<ion-toggle mode="foo"></ion-toggle>

No warning, falls back to default mode:

<p mode="ios">
  <ion-toggle></ion-toggle>
</p>
<p mode="md">
  <ion-toggle></ion-toggle>
</p>
<p mode="foo">
  <ion-toggle></ion-toggle>
</p>

Warning on foo, falls back to default mode:

<ion-segment mode="ios">
  <ion-segment-button>Button</ion-segment-button>
  <ion-segment-button>Button</ion-segment-button>
</ion-segment>
<ion-segment mode="md">
  <ion-segment-button>Button</ion-segment-button>
  <ion-segment-button>Button</ion-segment-button>
</ion-segment>
<ion-segment mode="foo">
  <ion-segment-button>Button</ion-segment-button>
  <ion-segment-button>Button</ion-segment-button>
</ion-segment>

Thank you for this! Awesome change.

[jakobe]

Great! The final changes looks great 👍

[brandyscarney]

This will be in the 5.0.6 release we're releasing in a bit. Thanks again. 🙂