Map block: Remove resize event listener when component is unmounted

[andrewserong]

If using the Map block in a custom block preview (for example as part of a pattern in the page layout picker in: Automattic/wp-calypso#49101), when the user switches their pattern selection and the Map block is unmounted, the resize listener continues to fire if the user resizes the window. This results in a TypeError in the console, because the DOM element for the Map component is no longer around:

The fix is to add a removeEventListener call when the component is unmounted.

Changes proposed in this Pull Request:

• In the Map block's main component, add a window.removeEventListener call to remove the resize listener when the component is unmounted.

Jetpack product discussion

Does this pull request change what data or activity we track or use?

No

Testing instructions:

• For an example where the bug occurred apply [Blocked] Starter page templates: Remove iframe from preview wp-calypso#49101 in a sandbox, and go to add a new page.
• Select a page layout that includes the Map component (the second last one under the Contact heading).
• Then, select a different page layout.
• Resize the window.
• Without this change applied, you should see an error message similar to the screenshot above
• With the change applied, particular error should not appear

Test for regressions:

• Insert the Map block (or a pattern containing it) into a post or page
• Resize the editor, and the Map block should resize
• Publish the post or page, and check that resizing the window resizes the Map block

Proposed changelog entry for your changes:

• Fix bug where Map block resize event listener was not removed when component unmounts

[matticbot]

Caution: This PR has changes that must be merged to WordPress.com
Hello andrewserong! These changes need to be synced to WordPress.com - If you 're an a11n, please commandeer and confirm D55824-code works as expected before merging this PR. Once this PR is merged, please commit the changes to WP.com. Thank you!
This revision will be updated with each commit to this PR

[jetpackbot]

Scheduled Jetpack release: February 2, 2021.
Scheduled code freeze: January 25, 2021

Thank you for the great PR description!

When this PR is ready for review, please apply the [Status] Needs Review label. If you are an a11n, please have someone from your team review the code if possible. The Jetpack team will also review this PR and merge it to be included in the next Jetpack release.

Generated by 🚫 dangerJS against 8a6b073

[glendaviesnz]

LGTM - the map contact page seems to have disappeared from the starter page templates, but you can replicate the issue by adding a map block to a post, deleting it and then resizing window

[andrewserong]

r220776-wpcom