Add TestCurrencyFormattingLogic in UnitConverterViewModelUnitTests

src/CalcViewModel/UnitConverterViewModel.cpp

@@ -227,9 +227,10 @@ void UnitConverterViewModel::OnUnitChanged(Object ^ parameter)
         return;
     }
 
+    m_model->SetCurrentUnitTypes(UnitFrom->GetModelUnit(), UnitTo->GetModelUnit());
+
     UpdateCurrencyFormatter();
 
-    m_model->SetCurrentUnitTypes(UnitFrom->GetModelUnit(), UnitTo->GetModelUnit());
     if (m_supplementaryResultsTimer != nullptr)
     {
         // End timer to show results immediately

src/CalculatorUnitTests/UnitConverterViewModelUnitTests.cpp

@@ -140,6 +140,7 @@ vector<UCM::Category> UnitConverterMock::GetCategories()
     cats.push_back(CAT1);
     cats.push_back(CAT2);
     cats.push_back(CAT3);
+    cats.push_back(CAT_CURRENCY);
 
     m_curCategory = CAT2;
 
@@ -174,6 +175,10 @@ UCM::CategorySelectionInitializer UnitConverterMock::SetCurrentCategory(const UC
         units.push_back(UNIT9);
         break;
     }
+    case CURRENCY_ID:
+        units.push_back(UNITJPY);
+        units.push_back(UNITJOD);
+        break;
     default:
         throw;
     }
@@ -215,10 +220,10 @@ void UnitConverterMock::SwitchActive(const std::wstring& newValue)
     m_curValue = newValue;
 }
 
-    std::wstring UnitConverterMock::SaveUserPreferences()
+std::wstring UnitConverterMock::SaveUserPreferences()
-    {
+{
     return L"TEST";
-    };
+};
 
 void UnitConverterMock::RestoreUserPreferences(_In_ std::wstring_view /*userPreferences*/){};
 
@@ -341,7 +346,7 @@ TEST_METHOD(TestUnitConverterLoadSetsUpCategories)
     VM::UnitConverterViewModel vm(mock);
     IObservableVector<VM::Category ^> ^ cats = vm.Categories;
     VERIFY_ARE_EQUAL((UINT)1, mock->m_getCategoriesCallCount);
-    VERIFY_ARE_EQUAL((UINT)3, cats->Size);
+    VERIFY_ARE_EQUAL((UINT)4, cats->Size);
     // Verify that we match current category
     VERIFY_IS_TRUE(CAT2 == vm.CurrentCategory->GetModelCategory());
 }
@@ -935,6 +940,33 @@ TEST_METHOD(TestDecimalFormattingLogic)
     VERIFY_IS_TRUE(vm.Value1 == L"3");
     VERIFY_IS_TRUE(vm.Value2 == L"2.50");
 }
+
+TEST_METHOD(TestCurrencyFormattingLogic)
+{
+    // verify that currency fraction digits is formatted per currency type
+
+    shared_ptr<UnitConverterMock> mock = make_shared<UnitConverterMock>();
+    VM::UnitConverterViewModel vm(mock);
+
+    // Establish base condition
+    vm.CurrentCategory = vm.Categories->GetAt(3); // Currency
+    vm.Unit1 = vm.Units->GetAt(0); // JPY
+    vm.Unit2 = vm.Units->GetAt(1); // JOD
+    vm.UnitChanged->Execute(nullptr);
+
+    const WCHAR *vFrom = L"1.2340", *vTo = L"0.0070";
+    vm.UpdateDisplay(vFrom, vTo);
+
+    VERIFY_IS_TRUE(vm.Value1 == L"1.");
+    VERIFY_IS_TRUE(vm.Value2 == L"0.007");
+    vm.SwitchActive->Execute(nullptr);
+    VERIFY_IS_TRUE(vm.Value1 == L"1"); // dangling decimal now removed
+    VERIFY_IS_TRUE(vm.Value2 == L"0.007");
+    vm.SwitchActive->Execute(nullptr);
+    VERIFY_IS_TRUE(vm.Value1 == L"1");
+    VERIFY_IS_TRUE(vm.Value2 == L"0.007");
+}
+
 // Tests that when we switch the active field and get display
 // updates, the correct automation names are are being updated.
 TEST_METHOD(TestValue1AndValue2AutomationNameChanges)

src/CalculatorUnitTests/UnitConverterViewModelUnitTests.h

@@ -9,6 +9,8 @@ namespace UCM = UnitConversionManager;
 
 namespace CalculatorUnitTests
 {
+    static constexpr int CURRENCY_ID = 16;
+
     static UCM::Unit UNIT1 = { 1, L"UNIT1", L"U1", true, false, false };
     static UCM::Unit UNIT2 = { 2, L"UNIT2", L"U2", false, true, false };
     static UCM::Unit UNIT3 = { 3, L"UNIT3", L"U3", false, false, false };
@@ -19,10 +21,13 @@ namespace CalculatorUnitTests
     static UCM::Unit UNIT8 = { 8, L"UNIT8", L"U8", false, false, false };
     static UCM::Unit UNIT9 = { 9, L"UNIT9", L"U9", true, false, false };
     static UCM::Unit UNITWHIMSY = { 10, L"Whimsy", L"UW", true, false, true };
+    static UCM::Unit UNITJPY = { 11, L"Japan - Yen", L"JPY", true, true, false };
+    static UCM::Unit UNITJOD = { 12, L"Jordan - Dinar", L"JOD", true, true, false };
 
     static UCM::Category CAT1 = { 1, L"CAT1", false };                       // contains Unit1 - Unit3
     static UCM::Category CAT2 = { 2, L"CAT2", false };                       // contains Unit4 - Unit6
     static UCM::Category CAT3 = { 3, L"CAT3", false };                       // contains Unit7 - Unit9
+    static UCM::Category CAT_CURRENCY = { CURRENCY_ID, L"Currency", false }; // contains UnitJPY and UnitJOD
 
     class UnitConverterMock : public UnitConversionManager::IUnitConverter
     {