From 1c09a2be55935619a6da59336e1c7e45393bcb9e Mon Sep 17 00:00:00 2001
From: bplu4t2f <bplu4t2f@gmail.com>
Date: Thu, 26 Feb 2026 20:49:36 +0100
Subject: [PATCH] Add tests for utf8_to_utf16_alloc, utf8_to_wstring_alloc

---
 tests/core/sys/windows/util.odin | 110 +++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/tests/core/sys/windows/util.odin b/tests/core/sys/windows/util.odin
index 638844416..777f85776 100644
--- a/tests/core/sys/windows/util.odin
+++ b/tests/core/sys/windows/util.odin
@@ -4,6 +4,7 @@ package test_core_sys_windows
 import "base:intrinsics"
 import "core:testing"
 import win32 "core:sys/windows"
+import runtime "base:runtime"
 
 UTF16_Vector :: struct {
 	wstr: win32.wstring,
@@ -142,3 +143,112 @@ utf8_to_wstring_buf_test :: proc(t : ^testing.T) {
 	// Buffer too short.
 	testing.expect(t, result == nil)
 }
+
+// Custom allocator proc that always returns dirty (non-zeroed) memory.
+dirty_allocator_proc :: proc(allocator_data: rawptr, mode: runtime.Allocator_Mode,
+                             size, alignment: int,
+                             old_memory: rawptr, old_size: int,
+                             location: runtime.Source_Code_Location = #caller_location) -> ([]byte, runtime.Allocator_Error) {
+	real_allocator := cast(^runtime.Allocator)allocator_data
+	bytes, error := real_allocator.procedure(real_allocator.data, mode,
+		size, alignment,
+		old_memory, old_size,
+		location)
+	if error == .None {
+		for i in 0 ..< len(bytes) {
+			// This will yield a 0 byte on overflow, but that does not matter in this test suite.
+			bytes[i] = cast(byte)(i + 1)
+		}
+	}
+	return bytes, error
+}
+
+@(test)
+utf8_to_utf16_alloc_test :: proc(t : ^testing.T) {
+	// We want to ensure that everything works with dirty
+	// (non-zeroed) memory returned from the allocator.
+	real_allocator := context.temp_allocator
+	allocator := runtime.Allocator {
+		procedure = dirty_allocator_proc,
+		data = cast(rawptr)&real_allocator,
+	}
+
+	// Test the dirty allocator.
+	allocator_test_slice := make([]u8, 100, allocator)
+	testing.expect_value(t, len(allocator_test_slice), 100)
+	for i in 0 ..< len(allocator_test_slice) {
+		testing.expect_value(t, allocator_test_slice[i], cast(u8)(i + 1))
+	}
+
+	result : []u16
+
+	result = win32.utf8_to_utf16_alloc("Hello\x00, World!", allocator)
+	testing.expect_value(t, len(result), 14)
+	testing.expect_value(t, result[4], 'o')
+	testing.expect_value(t, result[5], 0)
+	testing.expect_value(t, result[6], ',')
+	testing.expect_value(t, result[13], '!')
+
+	result = win32.utf8_to_utf16_alloc("H\x00\x00", allocator)
+	testing.expect_value(t, len(result), 3)
+	testing.expect_value(t, result[1], 0)
+	testing.expect_value(t, result[2], 0)
+
+	result = win32.utf8_to_utf16_alloc("你好，世界！", allocator)
+	testing.expect_value(t, len(result), 6)
+	testing.expect_value(t, result[0], 0x4F60)
+	testing.expect_value(t, result[1], 0x597D)
+	testing.expect_value(t, result[2], 0xFF0C)
+	testing.expect_value(t, result[3], 0x4E16)
+	testing.expect_value(t, result[4], 0x754C)
+	testing.expect_value(t, result[5], 0xFF01)
+
+	result = win32.utf8_to_utf16_alloc("", allocator)
+	// Valid, but indistinguishable from an error.
+	testing.expect_value(t, len(result), 0)
+}
+
+@(test)
+utf8_to_wstring_alloc_test :: proc(t : ^testing.T) {
+	// We want to ensure that everything works with dirty
+	// (non-zeroed) memory returned from the allocator.
+	backing_allocator := context.temp_allocator
+	allocator := runtime.Allocator {
+		procedure = dirty_allocator_proc,
+		data = cast(rawptr)&backing_allocator,
+	}
+
+	result : win32.wstring
+	buf : [^]u16
+
+	result = win32.utf8_to_wstring_alloc("Hello\x00, World!", allocator)
+	buf = transmute([^]u16)result
+	testing.expect(t, result != nil)
+	testing.expect_value(t, buf[4], 'o')
+	testing.expect_value(t, buf[5], 0)
+	testing.expect_value(t, buf[6], ',')
+	testing.expect_value(t, buf[13], '!')
+	testing.expect_value(t, buf[14], 0)
+
+	result = win32.utf8_to_wstring_alloc("H\x00\x00", allocator)
+	buf = transmute([^]u16)result
+	testing.expect(t, result != nil)
+	testing.expect_value(t, buf[1], 0)
+
+	result = win32.utf8_to_wstring_alloc("你好，世界！", allocator)
+	buf = transmute([^]u16)result
+	testing.expect(t, result != nil)
+	testing.expect_value(t, buf[0], 0x4F60)
+	testing.expect_value(t, buf[1], 0x597D)
+	testing.expect_value(t, buf[2], 0xFF0C)
+	testing.expect_value(t, buf[3], 0x4E16)
+	testing.expect_value(t, buf[4], 0x754C)
+	testing.expect_value(t, buf[5], 0xFF01)
+	testing.expect_value(t, buf[6], 0)
+
+	result = win32.utf8_to_wstring_alloc("", allocator)
+	buf = transmute([^]u16)result
+	// Valid, and distinguishable from an error.
+	testing.expect(t, result != nil)
+	testing.expect_value(t, buf[0], 0)
+}