Fix the issue that the initial values of the form on free listings editing page may be empty

[eason9487]

Changes proposed in this Pull Request:

This PR fixes the issue that the initial values of the form on free listings editing page may be empty.

Root cause

Since the values fetched from the APIs are updated asynchronously via useEffect, there is a chance that the default empty array in the wp-data store may be passed as the initial values to the form. As a result, empty form fields may appear occasionally when editing free listings because the empty array can pass checks in SetupFreeListings.

The issue usually happens on the shipping time data because it's almost always the last to be fetched.

Kapture.2024-11-28.at.18.57.41.mp4

Detailed test instructions:

1. Go to edit free listings
2. Check if the saved shipping rates and times are shown on the form
3. Refresh the webpage and check again
4. Repeat steps 2-3 several times to see if the issue won't appear occasionally

Changelog entry

Fix - The initial values of the form on free listings editing page may be empty.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 62.2%. Comparing base (16ff73f) to head (43b03e5).
Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
js/src/edit-free-campaign/index.js	0.0%	0 Missing and 4 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             develop   #2698      +/-   ##
============================================
- Coverage       65.1%   62.2%    -2.8%     
============================================
  Files            812     335     -477     
  Lines          24578    5147   -19431     
  Branches        1254    1256       +2     
============================================
- Hits           15990    3204   -12786     
+ Misses          8416    1769    -6647     
- Partials         172     174       +2     

Flag	Coverage Δ
js-unit-tests	62.2% <0.0%> (-<0.1%)	⬇️
php-unit-tests	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
js/src/edit-free-campaign/index.js	2.0% <0.0%> (-0.1%)	⬇️

... and 477 files with indirect coverage changes

[puntope]

Thanks @eason9487 for the quick fix. Works as expected for me. I refreshed several times. Like 10. And didn't happen.