--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-tmpdir.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,89 @@
+/* Copyright libuv project contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "task.h"
+#include <string.h>
+
+#define PATHMAX 4096
+#define SMALLPATH 1
+
+TEST_IMPL(tmpdir) {
+  char tmpdir[PATHMAX];
+  size_t len;
+  char last;
+  int r;
+
+  /* Test the normal case */
+  len = sizeof tmpdir;
+  tmpdir[0] = '\0';
+
+  ASSERT_OK(strlen(tmpdir));
+  r = uv_os_tmpdir(tmpdir, &len);
+  ASSERT_OK(r);
+  ASSERT_EQ(strlen(tmpdir), len);
+  ASSERT_GT(len, 0);
+  ASSERT_EQ(tmpdir[len], '\0');
+
+  if (len > 1) {
+    last = tmpdir[len - 1];
+#ifdef _WIN32
+    ASSERT_NE(last, '\\');
+#else
+    ASSERT_NE(last, '/');
+#endif
+  }
+
+  /* Test the case where the buffer is too small */
+  len = SMALLPATH;
+  r = uv_os_tmpdir(tmpdir, &len);
+  ASSERT_EQ(r, UV_ENOBUFS);
+  ASSERT_GT(len, SMALLPATH);
+
+  /* Test invalid inputs */
+  r = uv_os_tmpdir(NULL, &len);
+  ASSERT_EQ(r, UV_EINVAL);
+  r = uv_os_tmpdir(tmpdir, NULL);
+  ASSERT_EQ(r, UV_EINVAL);
+  len = 0;
+  r = uv_os_tmpdir(tmpdir, &len);
+  ASSERT_EQ(r, UV_EINVAL);
+
+#ifdef _WIN32
+  const char *name = "TMP";
+  char tmpdir_win[] = "C:\\xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
+  r = uv_os_setenv(name, tmpdir_win);
+  ASSERT_OK(r);
+  char tmpdirx[PATHMAX];
+  size_t lenx = sizeof tmpdirx;
+  r = uv_os_tmpdir(tmpdirx, &lenx);
+  ASSERT_OK(r);
+
+  /* Test empty environment variable */
+  r = uv_os_setenv("TMP", "");
+  ASSERT_EQ(r, 0);
+  len = sizeof tmpdir;
+  r = uv_os_tmpdir(tmpdir, &len);
+  ASSERT_EQ(r, UV_ENOENT);
+#endif
+
+  return 0;
+}