tests: use pytest instead of unittest

pytest provides session scoped fixtures, making it much easier
to reuse resources across tests.

tests/integration/test_nfc_open.py

@@ -4,20 +4,20 @@
 """Exercise NFC disk open and a one-sector write/read against the lab."""
 
 from openvixdisklib import nfc_open
-from tests.integration.base import TestBase
+from tests.integration.base import LabEnv, SECTOR_SIZE, pattern_bytes
 
 
-class NfcOpenTest(TestBase):
-    def test_open_disk_and_read_first_sector(self) -> None:
+class TestNfcOpen:
+    def test_open_disk_and_read_first_sector(self, lab: LabEnv) -> None:
         """Open the temp VMDK, write sector 0, and read it back."""
-        expected = self.pattern_bytes(self.SECTOR_SIZE, b"NFC-OPEN-S0")
-        with self.authenticate(read_only=False) as session:
+        expected = pattern_bytes(SECTOR_SIZE, b"NFC-OPEN-S0")
+        with lab.authenticate(read_only=False) as session:
             with nfc_open.open_disk(
-                    session, self.DISK_PATH, read_only=False) as disk:
-                self.assertEqual(disk.path, self.DISK_PATH)
-                self.assertGreater(disk.handle, 0)
-                self.assertEqual(disk.sector_size, self.SECTOR_SIZE)
+                    session, lab.disk_path, read_only=False) as disk:
+                assert disk.path == lab.disk_path
+                assert disk.handle > 0
+                assert disk.sector_size == SECTOR_SIZE
                 disk.write(0, 1, expected)
                 got = disk.read(0, 1)
-                self.assertIsNot(got, expected)
-                self.assertEqual(got, expected)
+                assert got is not expected
+                assert got == expected