[Shipping Labels] Handle dots in HS tariff number (#15933)

Merging as discussed in p1753281374928639-slack-C03L1NF1EA3

Author: RafaelKayumov

RELEASE-NOTES.txt

@@ -16,6 +16,7 @@
 - [*] Shipping Labels: Optimize data loading on purchase form [https://github.com/woocommerce/woocommerce-ios/pull/15919]
 - [*] Shipping Labels: Cache settings and origin addresses to improve loading experience for purchase form [https://github.com/woocommerce/woocommerce-ios/pull/15935]
 - [internal] Optimized assets for app size reduction [https://github.com/woocommerce/woocommerce-ios/pull/15881]
+- [*] Shipping Labels: Allow dots in HS tariff number input field for customs settings [https://github.com/woocommerce/woocommerce-ios/pull/15933]
 
 22.8
 -----

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

@@ -211,7 +211,7 @@ private extension WooShippingCustomsFormViewModel {
                     quantity: $0.itemQuantity,
                     value: Double($0.valuePerUnit) ?? 0,
                     weight: Double($0.weightPerUnit) ?? 0,
-                    hsTariffNumber: $0.isValidTariffNumber ? $0.hsTariffNumber : "",
+                    hsTariffNumber: $0.isValidTariffNumber ? $0.sanitizedHSTariffNumber : "",
                     originCountry: $0.selectedCountry?.code ?? "",
                     productID: $0.itemProductID
                 )

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

@@ -49,17 +49,11 @@ final class WooShippingCustomsItemViewModel: ObservableObject {
     }
 
     var isValidTariffNumber: Bool {
-        guard hsTariffNumber.isNotEmpty else {
-            return true
-        }
-
-        // Check if the string contains only digits
-        let digitsOnly = CharacterSet.decimalDigits.isSuperset(of: CharacterSet(charactersIn: hsTariffNumber))
-        guard digitsOnly else { return false }
+        return HSTariffNumberValidator.isNumberValid(hsTariffNumber)
+    }
 
-        // Check the length of the string
-        let length = hsTariffNumber.count
-        return length >= 6 && length <= 12
+    var sanitizedHSTariffNumber: String {
+        HSTariffNumberValidator.sanitize(hsTariffNumber)
     }
 
     @Published var requiredInformationIsEntered: Bool = false
@@ -150,3 +144,41 @@ private extension WooShippingCustomsItemViewModel {
             .store(in: &cancellables)
     }
 }
+
+/// Follows validation logic from `woocommerce-shipping/client/utils/customs.ts`
+enum HSTariffNumberValidator {
+    static let pattern = "^(\\d{1,2}\\.?){3,6}$"
+
+    /// Check if the HS Tariff Number is valid.
+    /// It should be a string of 6 to 12 digits, with optional dots in between every 2 digits.
+    /// - Parameter tariffNumber: The tariff number string.
+    /// - Returns: `Bool` if tariff number valid or not.
+    static func isNumberValid(_ tariffNumber: String) -> Bool {
+        if tariffNumber.isEmpty {
+            return true
+        }
+
+        let patternRange = tariffNumber.range(
+            of: pattern,
+            options: .regularExpression
+        )
+
+        if patternRange == nil {
+            return false
+        }
+
+        let digitsOnly = tariffNumber.components(
+            separatedBy: CharacterSet.decimalDigits.inverted
+        ).joined()
+        let count = digitsOnly.count
+        return count >= 6 && count <= 12
+    }
+
+    /// Sanitize the HS Tariff Number
+    /// Remove all non-digit characters
+    /// - Parameter tariffNumber: The tariff number string.
+    /// - Returns: Tariff string without non-digit characters
+    static func sanitize(_ tariffNumber: String) -> String {
+        return tariffNumber.components(separatedBy: CharacterSet.decimalDigits.inverted).joined()
+    }
+}

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

@@ -109,4 +109,41 @@ final class WooShippingCustomsItemViewModelTests: XCTestCase {
         XCTAssertEqual(viewModel.hsTariffNumberTotalValue?.0, viewModel.hsTariffNumber)
         XCTAssertEqual(viewModel.hsTariffNumberTotalValue?.1, Decimal(string: viewModel.valuePerUnit)! * 2)
     }
+
+    func test_isNumberValid_whenGivenValidTariffNumbers_shouldReturnTrue() {
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("123456"))
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("12.34.56"))
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("12.34.56.78"))
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("12.34.56.78.90"))
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("12.34.56.78.90.12"))
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("123456789012"))
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("12.345.678.90"))
+        XCTAssertTrue(HSTariffNumberValidator.isNumberValid("1.2.3.4.5.6"))
+    }
+
+    func test_isNumberValid_whenGivenInvalidTariffNumbers_shouldReturnFalse() {
+        // Less than 6 digits
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid("12345"))
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid("12.34.5"))
+
+        // More than 12 digits
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid("1234567890123"))
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid("12.34.56.78.90.123"))
+
+        // Invalid characters
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid("12345a"))
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid("12.34.5a"))
+
+        // Invalid structure
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid("12.34..56"))
+        XCTAssertFalse(HSTariffNumberValidator.isNumberValid(".123456"))
+    }
+
+    func test_hsTariffNumber_sanitize_whenGivenStringWithNonDigits_shouldReturnOnlyDigits() {
+        XCTAssertEqual(HSTariffNumberValidator.sanitize("12.34.56"), "123456")
+        XCTAssertEqual(HSTariffNumberValidator.sanitize("12a34b56c"), "123456")
+        XCTAssertEqual(HSTariffNumberValidator.sanitize("...123---456..."), "123456")
+        XCTAssertEqual(HSTariffNumberValidator.sanitize("123456"), "123456")
+        XCTAssertEqual(HSTariffNumberValidator.sanitize(""), "")
+    }
 }