From 42e3b43c7863bb5c4da2bfa952766af40c46c7b9 Mon Sep 17 00:00:00 2001
From: Younies Mahmoud <younies.mahmoud@gmail.com>
Date: Tue, 11 Feb 2025 14:04:34 +0000
Subject: [PATCH] ICU-22781 Add test for portion format with parts per billion
 (C++)

See #3389
---
 icu4c/source/test/intltest/numbertest.h       |  1 +
 icu4c/source/test/intltest/numbertest_api.cpp | 39 +++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/icu4c/source/test/intltest/numbertest.h b/icu4c/source/test/intltest/numbertest.h
index d384e0f22f2c..fe0d63393006 100644
--- a/icu4c/source/test/intltest/numbertest.h
+++ b/icu4c/source/test/intltest/numbertest.h
@@ -103,6 +103,7 @@ class NumberFormatterApiTest : public IntlTestWithFieldPosition {
     void toDecimalNumber();
     void microPropsInternals();
     void formatUnitsAliases();
+    void TestPortionFormat();
     void testIssue22378();
 
     void runIndexedTest(int32_t index, UBool exec, const char*& name, char* par = nullptr) override;
diff --git a/icu4c/source/test/intltest/numbertest_api.cpp b/icu4c/source/test/intltest/numbertest_api.cpp
index 4938818468e7..b44997a98168 100644
--- a/icu4c/source/test/intltest/numbertest_api.cpp
+++ b/icu4c/source/test/intltest/numbertest_api.cpp
@@ -133,6 +133,7 @@ void NumberFormatterApiTest::runIndexedTest(int32_t index, UBool exec, const cha
         TESTCASE_AUTO(toDecimalNumber);
         TESTCASE_AUTO(microPropsInternals);
         TESTCASE_AUTO(formatUnitsAliases);
+        TESTCASE_AUTO(TestPortionFormat);
         TESTCASE_AUTO(testIssue22378);
     TESTCASE_AUTO_END;
 }
@@ -6085,6 +6086,44 @@ void NumberFormatterApiTest::formatUnitsAliases() {
     }
 }
 
+void NumberFormatterApiTest::TestPortionFormat() {
+    IcuTestErrorCode status(*this, "TestPortionFormat");
+
+    struct TestCase {
+        const char *unitIdentifier;
+        const char *locale;
+        double inputValue;
+        UnicodeString expectedOutput;
+    } testCases[]{
+        {"portion-per-1e9", "en-US", 1, "1 part per billion"},
+        {"portion-per-1e9", "en-US", 2, "2 parts per billion"},
+        {"portion-per-1e9", "en-US", 1000000, "1,000,000 parts per billion"},
+        {"portion-per-1e9", "de-DE", 1000000, "1.000.000 Milliardstel"},
+        {"portion-per-1e1", "en-US", 1, "UNKNOWN"},
+        {"portion-per-1e2", "en-US", 1, "UNKNOWN"},
+        {"portion-per-1e3", "en-US", 1, "UNKNOWN"},
+        {"portion-per-1e4", "en-US", 1, "UNKNOWN"},
+        {"portion-per-1e5", "en-US", 1, "UNKNOWN"},
+        {"portion-per-1e6", "en-US", 1, "UNKNOWN"},
+        {"portion-per-1e7", "en-US", 1, "UNKNOWN"},
+        {"portion-per-1e8", "en-US", 1, "UNKNOWN"},
+    };
+
+    for (auto testCase : testCases) {
+        if (uprv_strcmp(testCase.unitIdentifier, "portion-per-1e9") != 0) {
+            logKnownIssue("CLDR-18274", "The data for portion-per-XYZ is not determined yet.");
+            continue;
+        }
+        MeasureUnit unit = MeasureUnit::forIdentifier(testCase.unitIdentifier, status);
+        LocalizedNumberFormatter lnf =
+            NumberFormatter::withLocale(Locale::forLanguageTag(testCase.locale, status))
+                .unit(unit)
+                .unitWidth(UNumberUnitWidth::UNUM_UNIT_WIDTH_FULL_NAME);
+        UnicodeString actualOutput = lnf.formatDouble(testCase.inputValue, status).toString(status);
+        assertEquals("test portion format", testCase.expectedOutput, actualOutput);
+    }
+}
+
 void NumberFormatterApiTest::testIssue22378() {
     IcuTestErrorCode status(*this, "testIssue22378");