[GOOWOO-777] Flat-rate shipping method fails to sync products to Merchant Center when WPML is inactive

[jamesmorrison]

Changes proposed in this Pull Request:

Closes https://linear.app/a8c/issue/GOOWOO-777/flat-rate-shipping-method-fails-to-sync-products-to-merchant-center

Note: this started from feature/GOOWOO-772-multi-lingual-feeds-fix-feedlabel-shipping-currency-and-sync-tracking / PR-3650

Screenshots:

Detailed test instructions:

Issue 1: markets priced in a currency the plugin cannot convert no longer sync (and clean themselves up)

Setup: a store connected to a real Merchant Centre account, with WPML and WooCommerce Multilingual active and multi-currency enabled, including a currency that is not the store's default (for example EUR on a GBP store).

1. On the Markets tab, add France as a secondary market with its currency set to EUR. Sync all products and confirm in Merchant Centre that the France entries exist under the FR-EUR feed label, and that "Shipping and returns" shows a France service in EUR.
2. Deactivate WPML and WooCommerce Multilingual via WP Admin > Plugins.
3. Load any admin page (this is when the plugin notices conversion is no longer available), then check Scheduled Actions: a pending "gla" update-all-products action and update-shipping-settings action should have been scheduled automatically. Run them.
4. Expected results:

• The sync completes with no "products failed to sync with Merchant Center" / "internal_error" entries in the logs. [Previously this setup failed the whole batch.]
• The France entries are removed from Merchant Centre, and the France shipping service disappears from "Shipping and returns".
• The France market is still listed on the Markets tab, untouched (nothing was deleted from the plugin's settings).
• The primary market's products, and any secondary market priced in the store currency, sync normally throughout.

5. Reactivate WPML and WooCommerce Multilingual (multi-currency on). Load an admin page, run the newly scheduled "gla" actions.

Expected: the France entries reappear in Merchant Centre under FR-EUR with converted prices, and the France shipping service returns.

Issue 2: Google's error codes are now recognised (retries, retry cap, and dead-entry cleanup work)

1. Pick a product that is synced to Merchant Centre.
2. In Merchant Centre itself, delete that product's entry directly (Products > All products > delete the entry).
3. In WooCommerce, make the plugin try to delete the same entry: move the product to bin, or set its Google visibility to "Don't sync and show".
4. Run the pending "gla" delete/cleanup scheduled action.

Expected: the log records "Attempted to delete product ... but it did not exist in Google Merchant Center, removing the synced product ID from database", and the plugin stops re-attempting that deletion on later runs. Previously this message never appeared and the dead entry was retried every time.

Additional details:

Fix - Fix issues with syncing (where market cannot provide price) and Google's error codes.

[codecov]

Codecov Report

❌ Patch coverage is 95.52239% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 70.9%. Comparing base (7328499) to head (7897db9).

Files with missing lines	Patch %	Lines
src/MerchantCenter/MarketService.php	90.4%	5 Missing ⚠️
...ternal/DependencyManagement/JobServiceProvider.php	0.0%	1 Missing ⚠️

Additional details and impacted files

@@                        Coverage Diff                        @@
##             feature/multi-lingual-support   #3573     +/-   ##
=================================================================
+ Coverage                             69.4%   70.9%   +1.5%     
- Complexity                            6110    6145     +35     
=================================================================
  Files                                  956     542    -414     
  Lines                                30919   23922   -6997     
  Branches                              1881       0   -1881     
=================================================================
- Hits                                 21455   16962   -4493     
+ Misses                                9193    6960   -2233     
+ Partials                               271       0    -271     

Flag	Coverage Δ
js-unit-tests	?
php-unit-tests	70.9% <95.5%> (+0.1%)	⬆️

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

Files with missing lines	Coverage Δ
src/API/Google/Settings.php	54.5% <100.0%> (+2.5%)	⬆️
src/Google/GoogleProductService.php	75.4% <100.0%> (+10.7%)	⬆️
src/Integration/WPML.php	78.4% <100.0%> (+0.4%)	⬆️
src/Jobs/UpdateShippingSettings.php	100.0% <100.0%> (ø)
src/Product/BatchProductHelper.php	96.4% <100.0%> (ø)
.../GoogleAdapter/AbstractShippingSettingsAdapter.php	84.4% <100.0%> (+1.6%)	⬆️
...ipping/GoogleAdapter/DBShippingSettingsAdapter.php	98.1% <100.0%> (+0.1%)	⬆️
...ipping/GoogleAdapter/WCShippingSettingsAdapter.php	97.9% <100.0%> (+0.1%)	⬆️
...ternal/DependencyManagement/JobServiceProvider.php	0.0% <0.0%> (ø)
src/MerchantCenter/MarketService.php	98.2% <90.4%> (-0.8%)	⬇️

... and 414 files with indirect coverage changes

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[joemcgill]

@jamesmorrison I'm not familiar with the requirements this issue relates to, but it looks like an important aspect of the IB has not been implemented here, summarized by Claude:

DBShippingSettingsAdapter::create_shipping_service() (src/Shipping/GoogleAdapter/DBShippingSettingsAdapter.php) still calls get_delivery_time($country), which throws InvalidValue unconditionally when a country has a flat-rate row (ShippingRateQuery) but no matching shipping-time row (ShippingTimeQuery). That exception propagates all the way up and aborts the entire shipping settings update for every country, not just the bad one — leaving Merchant Center's shipping config stale and causing exactly the internal_error product rejections the ticket reports.

Can you review?

[joemcgill]

Thanks for the updates, @jamesmorrison.