gh-108996: add tests for msvcrt (#109004)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
Co-authored-by: Steve Dower <steve.dower@microsoft.com>

Lib/test/test_msvcrt.py

@@ -0,0 +1,111 @@
+import os
+import sys
+import unittest
+
+from test.support import os_helper
+from test.support.os_helper import TESTFN, TESTFN_ASCII
+
+if sys.platform != "win32":
+    raise unittest.SkipTest("windows related tests")
+
+import _winapi
+import msvcrt;
+
+from _testconsole import write_input
+
+
+class TestFileOperations(unittest.TestCase):
+    def test_locking(self):
+        with open(TESTFN, "w") as f:
+            self.addCleanup(os_helper.unlink, TESTFN)
+
+            msvcrt.locking(f.fileno(), msvcrt.LK_LOCK, 1)
+            self.assertRaises(OSError, msvcrt.locking, f.fileno(), msvcrt.LK_NBLCK, 1)
+
+    def test_unlockfile(self):
+        with open(TESTFN, "w") as f:
+            self.addCleanup(os_helper.unlink, TESTFN)
+
+            msvcrt.locking(f.fileno(), msvcrt.LK_LOCK, 1)
+            msvcrt.locking(f.fileno(), msvcrt.LK_UNLCK, 1)
+            msvcrt.locking(f.fileno(), msvcrt.LK_LOCK, 1)
+
+    def test_setmode(self):
+        with open(TESTFN, "w") as f:
+            self.addCleanup(os_helper.unlink, TESTFN)
+
+            msvcrt.setmode(f.fileno(), os.O_BINARY)
+            msvcrt.setmode(f.fileno(), os.O_TEXT)
+
+    def test_open_osfhandle(self):
+        h = _winapi.CreateFile(TESTFN_ASCII, _winapi.GENERIC_WRITE, 0, 0, 1, 128, 0)
+        self.addCleanup(os_helper.unlink, TESTFN_ASCII)
+
+        try:
+            fd = msvcrt.open_osfhandle(h, os.O_RDONLY)
+            h = None
+            os.close(fd)
+        finally:
+            if h:
+                _winapi.CloseHandle(h)
+
+    def test_get_osfhandle(self):
+        with open(TESTFN, "w") as f:
+            self.addCleanup(os_helper.unlink, TESTFN)
+
+            msvcrt.get_osfhandle(f.fileno())
+
+
+c = '\u5b57'  # unicode CJK char (meaning 'character') for 'wide-char' tests
+c_encoded = b'\x57\x5b' # utf-16-le (which windows internally used) encoded char for this CJK char
+
+
+class TestConsoleIO(unittest.TestCase):
+    def test_kbhit(self):
+        self.assertEqual(msvcrt.kbhit(), 0)
+
+    def test_getch(self):
+        msvcrt.ungetch(b'c')
+        self.assertEqual(msvcrt.getch(), b'c')
+
+    def test_getwch(self):
+        stdin = open('CONIN$', 'r')
+        old_stdin = sys.stdin
+        try:
+            sys.stdin = stdin
+            write_input(stdin.buffer.raw, c_encoded)
+            self.assertEqual(msvcrt.getwch(), c)
+        finally:
+            sys.stdin = old_stdin
+
+    def test_getche(self):
+        msvcrt.ungetch(b'c')
+        self.assertEqual(msvcrt.getche(), b'c')
+
+    def test_getwche(self):
+        stdin = open('CONIN$', 'r')
+        old_stdin = sys.stdin
+        try:
+            sys.stdin = stdin
+            write_input(stdin.buffer.raw, c_encoded)
+            self.assertEqual(msvcrt.getwche(), c)
+        finally:
+            sys.stdin = old_stdin
+
+    def test_putch(self):
+        msvcrt.putch(b'c')
+
+    def test_putwch(self):
+        msvcrt.putwch(c)
+
+
+class TestOther(unittest.TestCase):
+    def test_heap_min(self):
+        try:
+            msvcrt.heapmin()
+        except OSError:
+            pass
+
+
+if __name__ == "__main__":
+    unittest.main()