1 files changed, 53 insertions, 0 deletions
diff --git a/tests/utf32.cpp b/tests/utf32.cpp
new file mode 100644
index 00000000..6b75b244
--- /dev/null
+++ b/tests/utf32.cpp
@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <string>
+#include <emscripten.h>
+#include <cassert>
+#include <wchar.h>
+
+typedef unsigned int utf32;
+typedef unsigned short utf16;
+
+// This code tests that Unicode std::wstrings can be marshalled between C++ and JS.
+int main() {
+	std::wstring wstr = L"abc\u2603\u20AC\U0002007C123 --- abc\u2603\u20AC\U0002007C123"; // U+2603 is snowman, U+20AC is the Euro sign, U+2007C is a Chinese Han character that looks like three raindrops.
+
+	printf("sizeof(wchar_t): %d.\n", (int)sizeof(wchar_t));
+
+	if (sizeof(wchar_t) == 4) {
+		utf32 *memory = new utf32[wstr.length()+1];
+
+		asm("var str = Module.UTF32ToString(%0);"
+			"Module.print(str);"
+			"Module.stringToUTF32(str, %1);"
+		:
+		: "r"(wstr.c_str()), "r"(memory));
+
+		// Compare memory to confirm that the string is intact after taking a route through JS side.
+		const utf32 *srcPtr = reinterpret_cast<const utf32 *>(wstr.c_str());
+		for(int i = 0;; ++i) {
+			assert(memory[i] == srcPtr[i]);
+			if (srcPtr[i] == 0)
+				break;
+		}
+		delete[] memory;
+	} else { // sizeof(wchar_t) == 2, and we're building with -fshort-wchar.
+		utf16 *memory = new utf16[2*wstr.length()+1];
+
+		asm("var str = Module.UTF16ToString(%0);"
+			"Module.print(str);"
+			"Module.stringToUTF16(str, %1);"
+		:
+		: "r"(wstr.c_str()), "r"(memory));
+
+		// Compare memory to confirm that the string is intact after taking a route through JS side.
+		const utf16 *srcPtr = reinterpret_cast<const utf16 *>(wstr.c_str());
+		for(int i = 0;; ++i) {
+			assert(memory[i] == srcPtr[i]);
+			if (srcPtr[i] == 0)
+				break;
+		}
+		delete[] memory;
+	}
+
+	printf("OK.\n");
+}