Add: Unit test for ICU ScriptRun.

This is based on srtest from the ICU codebase.

src/3rdparty/icu/CMakeLists.txt

@@ -1,3 +1,5 @@
+add_subdirectory(tests)
+
 add_files(
     scriptrun.cpp
     scriptrun.h

src/3rdparty/icu/tests/CMakeLists.txt

@@ -0,0 +1,4 @@
+add_test_files(
+    test_srtest.cpp
+    CONDITION ICU_i18n_FOUND
+)

src/3rdparty/icu/tests/test_srtest.cpp

@@ -0,0 +1,64 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+ * %W% %E%
+ *
+ * (C) Copyright IBM Corp. 2001-2016 - All Rights Reserved
+ *
+ */
+/** @file test_srtest.cpp Test icu::ScriptRun result. */
+
+#include "../../../3rdparty/catch2/catch.hpp"
+#include "../../../3rdparty/fmt/core.h"
+
+#include "../scriptrun.h"
+
+#include <span>
+#include <unicode/uscript.h>
+
+static void TestScriptRun(std::span<const char16_t> testChars, std::span<const std::string_view> testResults)
+{
+	icu::ScriptRun scriptRun(testChars.data(), 0, std::size(testChars));
+	size_t i = 0;
+
+	while (scriptRun.next()) {
+		int32_t start = scriptRun.getScriptStart();
+		int32_t end = scriptRun.getScriptEnd();
+		UScriptCode code = scriptRun.getScriptCode();
+
+		REQUIRE(i < std::size(testResults));
+		CHECK(fmt::format("Script '{}' from {} to {}.", uscript_getName(code), start, end) == testResults[i]);
+
+		++i;
+	}
+
+	REQUIRE(i == std::size(testResults));
+}
+
+TEST_CASE("ICU ScriptRun")
+{
+	/** Example string sequence as in srtest.cpp. */
+	static const char16_t testChars[] = {
+		0x0020, 0x0946, 0x0939, 0x093F, 0x0928, 0x094D, 0x0926, 0x0940, 0x0020,
+		0x0627, 0x0644, 0x0639, 0x0631, 0x0628, 0x064A, 0x0629, 0x0020,
+		0x0420, 0x0443, 0x0441, 0x0441, 0x043A, 0x0438, 0x0439, 0x0020,
+		'E', 'n', 'g', 'l', 'i', 's', 'h',  0x0020,
+		0x6F22, 0x5B75, 0x3068, 0x3072, 0x3089, 0x304C, 0x306A, 0x3068,
+		0x30AB, 0x30BF, 0x30AB, 0x30CA,
+		0xD801, 0xDC00, 0xD801, 0xDC01, 0xD801, 0xDC02, 0xD801, 0xDC03
+	};
+
+	/** Expected results from script run. */
+	static const std::string_view testResults[] = {
+		"Script 'Devanagari' from 0 to 9.",
+		"Script 'Arabic' from 9 to 17.",
+		"Script 'Cyrillic' from 17 to 25.",
+		"Script 'Latin' from 25 to 33.",
+		"Script 'Han' from 33 to 35.",
+		"Script 'Hiragana' from 35 to 41.",
+		"Script 'Katakana' from 41 to 45.",
+		"Script 'Deseret' from 45 to 53.",
+	};
+
+	TestScriptRun(testChars, testResults);
+}