add-product-flow

Use the sentinel copyWith pattern: define a private sentinel Object and default each nullable parameter to it, then only overwrite the field when the parameter differs from the sentinel. This skill applies it to errorMessage, latitude, and longitude in AddProductState.

The ProductAddImages StatefulWidget keeps local _imageModels state, so the ViewModel's state.imageModels stays empty unless the onImagesChanged callback fires after every pick or remove. Also use Image.memory with the non-nullable Uint8List bytes, never Image.network, for local picker images.

Enabling free shipping forces expressEnabled, sameDayEnabled, and freeShippingAt10Plus off because the backend zeroes all shipping tiers. Digital products force freeShipping=true and block unchecking, while local delivery only disables standard, express, and same-day options.

Guard the submit method with an early return when state.isLoading is true, placed at the top of addProduct(). This blocks duplicate product creation while the async create operation is in flight.

Use double.tryParse with a fallback instead of double.parse to avoid crashes, normalize postal codes by removing spaces before the Canadian regex, and call clearCoordinates() when street, city, or postal code is manually edited to avoid stale geolocation.