don't keep the file open on Windows

Author: oconnor663

tests/test_blake3.py

@@ -2,6 +2,7 @@
 from binascii import unhexlify
 import json
 import numpy
+import os
 from pathlib import Path
 import subprocess
 import sys
@@ -433,22 +434,25 @@ def test_module_name() -> None:
 
 def test_mmap() -> None:
     input_bytes = bytes([42]) * 1_000_000
-    with tempfile.NamedTemporaryFile() as f:
+    # Note that we can't use NamedTemporaryFile here, because we can't open it
+    # again on Windows.
+    (fd, temp_path) = tempfile.mkstemp()
+    os.close(fd)
+    with open(temp_path, "wb") as f:
         f.write(input_bytes)
-        f.flush()
-
-        # Test all three threading modes, and both str and Path arguments. Note
-        # that PyO3 doesn't support converting Python bytes to a Rust PathBuf,
-        # I think because that's not generally possible on Windows.
-        hasher1 = blake3()
-        hasher1.update_mmap(f.name)
-        assert blake3(input_bytes).digest() == hasher1.digest()
-
-        hasher2 = blake3(max_threads=blake3.AUTO)
-        hasher2.update_mmap(Path(f.name))
-        assert blake3(input_bytes).digest() == hasher2.digest()
-
-        hasher3 = blake3(max_threads=4)
-        hasher3.update_mmap(path=f.name)
-        hasher3.update_mmap(path=Path(f.name))
-        assert blake3(2 * input_bytes).digest() == hasher3.digest()
+
+    # Test all three threading modes, and both str and Path arguments. Note
+    # that PyO3 doesn't support converting Python bytes to a Rust PathBuf,
+    # I think because that's not generally possible on Windows.
+    hasher1 = blake3()
+    hasher1.update_mmap(temp_path)
+    assert blake3(input_bytes).digest() == hasher1.digest()
+
+    hasher2 = blake3(max_threads=blake3.AUTO)
+    hasher2.update_mmap(Path(temp_path))
+    assert blake3(input_bytes).digest() == hasher2.digest()
+
+    hasher3 = blake3(max_threads=4)
+    hasher3.update_mmap(temp_path)
+    hasher3.update_mmap(path=Path(temp_path))
+    assert blake3(2 * input_bytes).digest() == hasher3.digest()