ICU-23105 Update NumberFormatterApiTest/formatUnitsAliases to fail when the units are not parsable

- Refactor test cases to use unique_ptr for MeasureUnit in C++ and adjust constructor in Java.
- Introduce logging for known issues related to unit aliases to ensure compatibility with callers.
- Update expected formats for unit aliases in both C++ and Java test files.

Author: younies

icu4c/source/test/intltest/numbertest_api.cpp

@@ -6059,30 +6059,40 @@ void NumberFormatterApiTest::microPropsInternals() {
 void NumberFormatterApiTest::formatUnitsAliases() {
     IcuTestErrorCode status(*this, "formatUnitsAliases");
 
-    if (logKnownIssue("ICU-23105", "With CLDR 48m1, C++ NumberFormatterApiTest::formatUnitsAliases fails (J passes)")) {
-        return;
-    }
     struct TestCase {
-        const MeasureUnit measureUnit;
+        std::unique_ptr<MeasureUnit> measureUnit;
+        const char * measureUnitString; // Only used if measureUnit is nullptr
         const UnicodeString expectedFormat;
     } testCases[]{
         // Aliases
-        {MeasureUnit::getMilligramPerDeciliter(), u"2 milligrams per deciliter"},
-        {MeasureUnit::getLiterPer100Kilometers(), u"2 liters per 100 kilometers"},
-        {MeasureUnit::getPartPerMillion(), u"2 parts per million"},
-        {MeasureUnit::forIdentifier("permillion", status), u"2 parts per million"},
-        {MeasureUnit::getMillimeterOfMercury(), u"2 millimeters of mercury"},
+        {std::make_unique<MeasureUnit>(MeasureUnit::getMilligramOfglucosePerDeciliter()), nullptr, u"2 milligrams per deciliter"},
+        {std::make_unique<MeasureUnit>(MeasureUnit::getMilligramPerDeciliter()), nullptr, u"2 milligrams per deciliter"},
+        {std::make_unique<MeasureUnit>(MeasureUnit::getLiterPer100Kilometers()), nullptr,u"2 liters per 100 kilometers"},
+        {std::make_unique<MeasureUnit>(MeasureUnit::getPartPerMillion()), nullptr, u"2 parts per million"},
+        {std::make_unique<MeasureUnit>(MeasureUnit::getMillimeterOfMercury()), nullptr, u"2 millimeters of mercury"},
 
         // Some replacements
-        {MeasureUnit::getMilligramOfglucosePerDeciliter(), u"2 milligrams per deciliter"},
-        {MeasureUnit::getLiterPer100Kilometers(), u"2 liters per 100 kilometers"},
-        {MeasureUnit::getPartPer1E6(), u"2 parts per million"},
-        {MeasureUnit::forIdentifier("millimeter-ofhg", status), u"2 millimeters of mercury"},
+        {nullptr, "millimeter-ofhg", u"2 millimeters of mercury"},
+        {nullptr, "liter-per-100-kilometer", u"2 liters per 100 kilometers"},
+        {nullptr, "permillion", u"2 parts per million"},
+        {nullptr, "part-per-million", u"2 parts per million"},
+        {nullptr, "part-per-1e6", u"2 parts per million"},
     };
 
     for (const auto &testCase : testCases) {
+        if (testCase.measureUnitString != nullptr && 
+            (uprv_strcmp("permillion", testCase.measureUnitString) == 0 ||
+             uprv_strcmp("part-per-million", testCase.measureUnitString) == 0)) {
+            logKnownIssue("ICU-23222", "Ensure unit aliases work correctly to avoid breaking callers");
+            continue;
+        }
+
+        MeasureUnit unit = testCase.measureUnit ? *testCase.measureUnit : MeasureUnit::forIdentifier(testCase.measureUnitString, status);
+        if (status.errIfFailureAndReset()) {
+                continue;
+        }
         UnicodeString actualFormat = NumberFormatter::withLocale(icu::Locale::getEnglish())
-                                         .unit(testCase.measureUnit)
+                                         .unit(unit)
                                          .unitWidth(UNumberUnitWidth::UNUM_UNIT_WIDTH_FULL_NAME)
                                          .formatDouble(2.0, status)
                                          .toString(status);

icu4j/main/common_tests/src/test/java/com/ibm/icu/dev/test/number/NumberFormatterApiTest.java

@@ -5995,32 +5995,49 @@ public void formatUnitsAliases() {
 
         class TestCase {
             final MeasureUnit measureUnit;
+            final String measureUnitString; // Only used if measureUnit is nullptr
             final String expectedFormat;
 
             TestCase(MeasureUnit measureUnit, String expectedFormat) {
                 this.measureUnit = measureUnit;
+                this.measureUnitString = null;
+                this.expectedFormat = expectedFormat;
+            }
+
+            TestCase(String measureUnitString, String expectedFormat) {
+                this.measureUnit = null;
+                this.measureUnitString = measureUnitString;
                 this.expectedFormat = expectedFormat;
             }
         }
 
         TestCase[] testCases = {
                 // Aliases
+                new TestCase(MeasureUnit.MILLIGRAM_OFGLUCOSE_PER_DECILITER, "2 milligrams per deciliter"),
                 new TestCase(MeasureUnit.MILLIGRAM_PER_DECILITER, "2 milligrams per deciliter"),
                 new TestCase(MeasureUnit.LITER_PER_100KILOMETERS, "2 liters per 100 kilometers"),
                 new TestCase(MeasureUnit.PART_PER_MILLION, "2 parts per million"),
                 new TestCase(MeasureUnit.MILLIMETER_OF_MERCURY, "2 millimeters of mercury"),
 
                 // Replacements
-                new TestCase(MeasureUnit.MILLIGRAM_OFGLUCOSE_PER_DECILITER, "2 milligrams per deciliter"),
-                new TestCase(MeasureUnit.forIdentifier("millimeter-ofhg"), "2 millimeters of mercury"),
-                new TestCase(MeasureUnit.forIdentifier("liter-per-100-kilometer"), "2 liters per 100 kilometers"),
-                new TestCase(MeasureUnit.forIdentifier("part-per-1e6"), "2 parts per million"),
+                new TestCase("millimeter-ofhg", "2 millimeters of mercury"),
+                new TestCase("liter-per-100-kilometer", "2 liters per 100 kilometers"),
+                new TestCase("permillion", "2 parts per million"),
+                new TestCase("part-per-million", "2 parts per million"),
+                new TestCase("part-per-1e6", "2 parts per million"),
         };
 
         for (TestCase testCase : testCases) {
+            if ("permillion".equals(testCase.measureUnitString) ||
+                "part-per-million".equals(testCase.measureUnitString)) {
+                logKnownIssue("ICU-23222", "Ensure unit aliases work correctly to avoid breaking callers");
+                continue;
+            }
+
+            MeasureUnit measureUnit = testCase.measureUnitString != null ? MeasureUnit.forIdentifier(testCase.measureUnitString) : testCase.measureUnit;
             String actualFormat = NumberFormatter
                     .withLocale(ULocale.ENGLISH)
-                    .unit(testCase.measureUnit)
+                    .unit(measureUnit)
                     .unitWidth(UnitWidth.FULL_NAME)
                     .format(2.0)
                     .toString();