cleanups, add mock test

pytools/persistent_dict.py

@@ -331,14 +331,15 @@ def update_for_specific_dtype(self, key_hash: Hash, key: Any) -> None:
 
     def update_for_numpy_scalar(self, key_hash: Hash, key: Any) -> None:
         import numpy as np
-        if IS_BIGENDIAN:
-            key = key.byteswap()
         if hasattr(np, "complex256") and key.dtype == np.dtype("complex256"):
             key_hash.update(repr(complex(key)).encode("utf8"))
         elif hasattr(np, "float128") and key.dtype == np.dtype("float128"):
             key_hash.update(repr(float(key)).encode("utf8"))
         else:
-            key_hash.update(np.array(key).tobytes())
+            if IS_BIGENDIAN:
+                key_hash.update(np.array(key).byteswap().tobytes())
+            else:
+                key_hash.update(np.array(key).tobytes())
 
     def update_for_dataclass(self, key_hash: Hash, key: Any) -> None:
         self.rec(key_hash, f"{type(key).__qualname__}.{type(key).__name__}")

pytools/test/test_persistent_dict.py

@@ -479,6 +479,19 @@ def test_scalar_hashing() -> None:
         assert keyb(np.complex256(1.1+2.2j)) == keyb(np.complex256(1.1+2.2j))
     assert keyb(np.clongdouble(1.1+2.2j)) == keyb(np.clongdouble(1.1+2.2j))
 
+    h_int64 = keyb(np.int64(1))
+
+    import unittest.mock
+    with unittest.mock.patch("pytools.persistent_dict.IS_BIGENDIAN", True):
+        # Very crude big-endian test. Apparently, there is no way to
+        # create a numpy scalar (not an np.array!) of a specific byte order.
+        if sys.byteorder == "big":
+            # no need to swap
+            be_val = np.int64(1)
+        else:
+            be_val = np.int64(1).byteswap()
+        assert h_int64 == keyb(be_val)
+
 
 @pytest.mark.parametrize("dict_impl", ("immutabledict", "frozendict",
                                        "constantdict",