[Shipping Labels] Handle zero weight in customs form (#15927)

Author: RafaelKayumov

RELEASE-NOTES.txt

@@ -16,6 +16,7 @@
 - [*] Watch app: Fixed connection issue upon fresh install [https://github.com/woocommerce/woocommerce-ios/pull/15867]
 - [Internal] Shipping Labels: Optimize requests for syncing countries [https://github.com/woocommerce/woocommerce-ios/pull/15875]
 - [*] Shipping Labels: Display label size from account settings as default [https://github.com/woocommerce/woocommerce-ios/pull/15873]
+- [*] Shipping Labels: Ensured customs form validation enforces non-zero product weight to fix shipping rate loading failure. [https://github.com/woocommerce/woocommerce-ios/pull/15927]
 
 22.7
 -----

WooCommerce/Classes/ViewRelated/Orders/Order Details/Shipping Labels/WooShipping Create Shipping Labels/WooShipping Customs/WooShippingCustomsItem.swift

@@ -11,7 +11,6 @@ struct WooShippingCustomsItem: View {
     @State private var isShowingDescriptionInfoDialog = false
     @State private var isShowingOriginCountryInfoDialog = false
 
-
     @Environment(\.shippingWeightUnit) var weightUnit: String
 
     var body: some View {
@@ -167,12 +166,12 @@ struct WooShippingCustomsItem: View {
                                 .padding(.trailing, Layout.unitsHorizontalSpacing)
                         }
                         .roundedBorder(cornerRadius: Layout.borderCornerRadius,
-                                       lineColor: viewModel.weightPerUnit.isEmpty ? warningRedColor : Color(.separator),
+                                       lineColor: viewModel.isValidWeight ? Color(.separator) : warningRedColor,
                                        lineWidth: Layout.borderLineWidth)
                         Text(Localization.valueRequiredWarningText)
                             .foregroundColor(warningRedColor)
                             .footnoteStyle()
-                            .renderedIf(viewModel.weightPerUnit.isEmpty)
+                            .renderedIf(!viewModel.isValidWeight)
                     }
                 }
                 .padding(.bottom, Layout.collapsibleViewVerticalSpacing)

WooCommerce/Classes/ViewRelated/Orders/Order Details/Shipping Labels/WooShipping Create Shipping Labels/WooShipping Customs/WooShippingCustomsItemViewModel.swift

@@ -62,6 +62,10 @@ final class WooShippingCustomsItemViewModel: ObservableObject {
         return length >= 6 && length <= 12
     }
 
+    var isValidWeight: Bool {
+        return Self.isWeightValid(weightPerUnit)
+    }
+
     @Published var requiredInformationIsEntered: Bool = false
 
     private var cancellables = Set<AnyCancellable>()
@@ -79,7 +83,12 @@ final class WooShippingCustomsItemViewModel: ObservableObject {
         self.itemProductID = itemProductID
         self.itemQuantity = itemQuantity
         self.valuePerUnit = String(itemValue)
-        self.weightPerUnit = String(itemWeight)
+
+        /// Skip zero weight
+        if Self.isWeightNonZero(itemWeight) {
+            self.weightPerUnit = String(itemWeight)
+        }
+
         self.currencySymbol = currencySymbol
         self.storageManager = storageManager
 
@@ -127,7 +136,11 @@ private extension WooShippingCustomsItemViewModel {
     func combineRequiredInformationIsEntered() {
         Publishers.CombineLatest4($description, $valuePerUnit, $weightPerUnit, $selectedCountry)
             .sink { [weak self] description, valuePerUnit, weightPerUnit, selectedCountry in
-                self?.requiredInformationIsEntered = description.isNotEmpty && valuePerUnit.isNotEmpty && weightPerUnit.isNotEmpty && selectedCountry != nil
+                guard let self else { return }
+                requiredInformationIsEntered = description.isNotEmpty &&
+                valuePerUnit.isNotEmpty &&
+                Self.isWeightValid(weightPerUnit) &&
+                selectedCountry != nil
             }
             .store(in: &cancellables)
     }
@@ -149,4 +162,13 @@ private extension WooShippingCustomsItemViewModel {
             }
             .store(in: &cancellables)
     }
+
+    /// Specifically introduced to check for a `0` value
+    static func isWeightValid(_ weightString: String) -> Bool {
+        return isWeightNonZero(Double(weightString) ?? 0)
+    }
+
+    static func isWeightNonZero(_ weightValue: Double) -> Bool {
+        return weightValue > 0
+    }
 }

WooCommerce/WooCommerceTests/ViewRelated/Shipping Label/WooShipping Create Shipping Labels/WooShipping Customs/WooShippingCustomsFormViewModelTests.swift

@@ -1,5 +1,6 @@
 import XCTest
 import Yosemite
+import Combine
 @testable import WooCommerce
 
 final class WooShippingCustomsFormViewModelTests: XCTestCase {
@@ -332,6 +333,67 @@ final class WooShippingCustomsFormViewModelTests: XCTestCase {
         XCTAssertEqual(firstItemViewModel?.valuePerUnit, String(firstItem?.value ?? 0))
         XCTAssertEqual(firstItemViewModel?.weightPerUnit, String(firstItem?.weight ?? 0))
     }
+
+    func test_requiredInformationIsEntered_when_weight_is_zero_then_returns_false() {
+        // Given
+        let storageManager = MockStorageManager()
+        let originCountryCodeSubject = PassthroughSubject<String?, Never>()
+
+        let country = Country(
+            code: "US",
+            name: "United States",
+            states: []
+        )
+        storageManager.insertSampleCountries(readOnlyCountries: [country])
+
+        let itemWithZeroWeight = ShippingLabelPackageItem(
+            productOrVariationID: 1,
+            orderItemID: 123,
+            name: "Shirt",
+            weight: 0,
+            quantity: 1,
+            value: 10,
+            dimensions: .fake(),
+            attributes: [],
+            imageURL: nil
+        )
+
+        let shipment = Shipment(
+            contents: [
+                CollapsibleShipmentItemCardViewModel(
+                    item: itemWithZeroWeight,
+                    currency: "USD"
+                )
+            ],
+            currency: "USD",
+            currencySettings: ServiceLocator.currencySettings,
+            shippingSettingsService: ServiceLocator.shippingSettingsService
+        )
+
+        viewModel = WooShippingCustomsFormViewModel(
+            order: .fake(),
+            shipment: shipment,
+            originCountryCode: originCountryCodeSubject.eraseToAnyPublisher(),
+            storageManager: storageManager,
+            onFormReady: { _ in }
+        )
+
+        let itemViewModel = viewModel.itemsViewModels[0]
+        itemViewModel.description = "Test Description"
+        itemViewModel.valuePerUnit = "10.0"
+
+        // When
+        originCountryCodeSubject.send("US")
+
+        // Then
+        XCTAssertFalse(
+            viewModel.requiredInformationIsEntered,
+            "requiredInformationIsEntered should be false when an item's weight is zero"
+        )
+        XCTAssertTrue(itemViewModel.weightPerUnit.isEmpty)
+        XCTAssertFalse(itemViewModel.isValidWeight)
+        XCTAssertFalse(itemViewModel.requiredInformationIsEntered)
+    }
 }
 
 private extension WooShippingCustomsFormViewModelTests {

WooCommerce/WooCommerceTests/ViewRelated/Shipping Label/WooShipping Create Shipping Labels/WooShipping Customs/WooShippingCustomsItemViewModelTests.swift

@@ -49,6 +49,23 @@ final class WooShippingCustomsItemViewModelTests: XCTestCase {
         XCTAssertTrue(viewModel.isValidTariffNumber)
     }
 
+    func test_when_item_weight_is_zero_then_it_is_invalid() {
+        // Given
+        let viewModel = WooShippingCustomsItemViewModel(
+            itemName: "Test",
+            itemProductID: 22,
+            itemQuantity: 1,
+            itemValue: 10,
+            itemWeight: 0,
+            currencySymbol: "$",
+            storageManager: MockStorageManager()
+        )
+
+        // Then
+        XCTAssertTrue(viewModel.weightPerUnit.isEmpty, "Weight should be empty it the initial value is zero")
+        XCTAssertFalse(viewModel.isValidWeight, "isValidWeight should be false when the weight is zero")
+    }
+
     func test_hsTariffNumberTotalValue_when_currency_symbol_is_not_$_returns_nil() {
         // Given
         viewModel = WooShippingCustomsItemViewModel(itemName: "Test",