Fix some primary category issues

[dkotter]

Description of the Change

This is a follow up to #350.

If Yoast is not being used, everything works as expected. But if Yoast is installed, if no category is selected, we return the value null, which breaks our sync. This PR adjust our get_primary_category function to add some better checks, ensuring if we don't have a primary category set we fallback to grabbing the first category set. Or if we have a primary category set but that category no longer exists, we now check for that and return false instead.

If we return false in this function, we've also adjusted the output to the tracker to ensure we are sending an empty array instead of an array with an empty string in it.

Alternate Designs

None

Possible Drawbacks

None

Verification Process

Verify that setting categories sends the correct data to Sophi both with Yoast installed and with it not. Try setting one category, multiple categories and no categories.

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

No Coverage information
0.0% Duplication

[dkotter]

@jeffpaul @Sidsector9 This PR should fix the issues where we can end up with either [null] or [''] being sent to the tracker.

One thing I noticed that may have already been discussed: since we are relying on Yoast here to set the primary category, and Yoast does this using post meta and the block editor saves post meta in a separate request from saving the post itself, we end up with two requests being sent to the tracker. The first may or may not have the proper category set, since the post meta will not have been saved at that time.

Not sure how these duplicate tracking events impact things, if at all, but figured I'd mention it

[jeffpaul]

As long as the last sync for the update includes the correct category(ies), then the content sync to Sophi will result in the "right" data being available for Sophi to process; so I think we're ok on this.