Add the ability to pin notifications

[nfmohit]

Summary

Addresses issue:

• Audience Segmentation oAuth Setup interrupted by another banner in queue #10890

Relevant technical choices

This PR adds the ability to pin notifications in case they need to appear after a subsequent page load, such as an OAuth flow for continuity.

PR Author Checklist

• My code is tested and passes existing unit tests.
• My code has an appropriate set of unit tests which all pass.
• My code is backward-compatible with WordPress 5.2 and PHP 7.4.
• My code follows the WordPress coding standards.
• My code has proper inline documentation.
• I have added a QA Brief on the issue linked above.
• I have signed the Contributor License Agreement (see https://cla.developers.google.com/).

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Code Reviewer Checklist

• Run the code.
• Ensure the acceptance criteria are satisfied.
• Reassess the implementation with the IB.
• Ensure no unrelated changes are included.
• Ensure CI checks pass.
• Check Storybook where applicable.
• Ensure there is a QA Brief.
• Ensure there are no unexpected significant changes to file sizes.

Merge Reviewer Checklist

• Ensure the PR has the correct target branch.
• Double-check that the PR is okay to be merged.
• Ensure the corresponding issue has a ZenHub release assigned.
• Add a changelog message to the issue.

[techanvil]

Hey @nfmohit, thanks for working on this.

Unfortunately though, in my testing it's not working as expected. I'm seeing this error when returning to the dashboard from OAuth:

Here's a screencast:

10890-error-returning-from-oauth.webm

Digging in, it looks like snapshotting is stripping the Component, check, and checkRequirements functions out of the state.

Here I've console logged the queuedNotifications array before the snapshot:

And after the snapshot:

This is something we overlooked at the IB stage. It's not possible to serialise functions to JSON, so the CORE_NOTIFICATIONS datastore is not a good candidate for snapshotting. In fact, it's not good practice to store functions in state at all, for this reason. We should ideally refactor our state management to avoid this, but this is something to address separately - I'll add an issue to look into this.

In the meantime, we'll need to change the approach for this enhancement. For example, we could store the pinned state in a separate store which can be snapshotted.

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On a separate note, we actually have a workaround for this bug in develop whereby we've lowered the priority for the affected notifications. We should revert the priority to PRIORITY.SETUP_CTA_LOW in this PR, we don't need to wait until it's merged.

site-kit-wp/assets/js/modules/analytics-4/index.js

Line 729 in 7ec077d

priority: 130, // TODO: Revert this back to PRIORITY.SETUP_CTA_LOW after fixing https://github.com/google/site-kit-wp/issues/10890.

site-kit-wp/assets/js/modules/analytics-4/index.js

Line 876 in 7ec077d

priority: 140, // TODO: Revert this back to PRIORITY.SETUP_CTA_LOW after fixing https://github.com/google/site-kit-wp/issues/10890.