fix: don't accept inane input

Author: d-v-b

src/zarr/core/chunk_grids.py

@@ -680,17 +680,17 @@ def _guess_regular_chunks(
     return tuple(int(x) for x in chunks)
 
 
-def normalize_chunks_1d(chunks: int | None | Iterable[int], span: int) -> tuple[int, ...]:
+def normalize_chunks_1d(chunks: int | Iterable[int], span: int) -> tuple[int, ...]:
     """
     Normalize a one-dimensional chunk specification into a tuple of logical
     chunk sizes that cover the span.
 
-    `None` and `-1` both mean "one chunk covering the entire span."
+    `-1` means "one chunk covering the entire span."
     For an integer chunk size, all chunks are uniform — the last chunk may
     overhang the span. The actual data extent of each chunk is determined
     by the chunk grid at runtime, not by this function.
     """
-    if chunks is None or chunks == -1:
+    if chunks == -1:
         return (span,)
     if isinstance(chunks, int):
         if chunks <= 0:
@@ -738,14 +738,13 @@ def normalize_chunks_nd(
         chunks = tuple(int(chunks) for _ in shape)
 
     # handle bad dimensionality
-    if len(chunks) > len(shape):
-        raise ValueError("too many dimensions in chunks")
-
-    # pad short specs with None (meaning "use span") for remaining dimensions
-    padded = tuple(chunks) + (None,) * (len(shape) - len(chunks))
+    if len(chunks) != len(shape):
+        raise ValueError(
+            f"chunks has {len(chunks)} dimensions but shape has {len(shape)} dimensions"
+        )
 
     return ChunksTuple(
-        tuple(normalize_chunks_1d(c, span=s) for c, s in zip(padded, shape, strict=True))
+        tuple(normalize_chunks_1d(c, span=s) for c, s in zip(chunks, shape, strict=True))
     )
 
 

tests/test_chunk_grids.py

@@ -34,13 +34,11 @@ def test_guess_chunks(shape: tuple[int, ...], itemsize: int) -> None:
         # 2D cases
         ((10, 10), (100, 10), ((10,) * 10, (10,))),
         (10, (100, 10), ((10,) * 10, (10,))),
-        ((10, None), (100, 10), ((10,) * 10, (10,))),
+        ((10, -1), (100, 10), ((10,) * 10, (10,))),
         # 3D cases
         (30, (100, 20, 10), ((30, 30, 30, 30), (30,), (30,))),
-        ((30,), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
-        ((30, None), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
-        ((30, None, None), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
-        ((30, 20, None), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
+        ((30, -1, -1), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
+        ((30, 20, -1), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
         ((30, 20, 10), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
         # dask-style chunks (explicit per-chunk sizes)
         (((100, 100, 100), (50, 50)), (300, 100), ((100, 100, 100), (50, 50))),
@@ -51,7 +49,6 @@ def test_guess_chunks(shape: tuple[int, ...], itemsize: int) -> None:
         (False, (100, 50), ((100,), (50,))),
         # sentinel values
         (-1, (100,), ((100,),)),
-        ((30, -1, None), (100, 20, 10), ((30, 30, 30, 30), (20,), (10,))),
         # zero-length dimensions preserve the declared chunk size
         (10, (0,), ((10,),)),
         ((5, 10), (0, 100), ((5,), (10,) * 10)),
@@ -97,5 +94,7 @@ def test_normalize_chunks_errors() -> None:
         normalize_chunks_nd(None, (100,))
     with pytest.raises(ValueError):
         normalize_chunks_nd("foo", (100,))
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match="dimensions"):
         normalize_chunks_nd((100, 10), (100,))
+    with pytest.raises(ValueError, match="dimensions"):
+        normalize_chunks_nd((10,), (100, 100))

tests/test_codecs/test_sharding.py

@@ -497,7 +497,7 @@ def test_invalid_shard_shape() -> None:
             {},
             shape=(16, 16),
             shards=(16, 16),
-            chunks=(9,),
+            chunks=(9, 9),
             dtype=np.dtype("uint8"),
             fill_value=0,
         )