add a small test

b2h5py/tests/test_b2dataset.py

@@ -0,0 +1,37 @@
+"""Test using B2Dataset to enable fast access to Blosc2 compressed dataset.
+"""
+
+import h5py
+import hdf5plugin
+import numpy as np
+import pytest
+
+from b2h5py import B2Dataset
+
+
+@pytest.fixture
+def hdf5_test_dataset(tmp_path):
+    """Text fixture creating a hdf5 file with a "data" dataset compression with Blosc2"""
+    shape = 3500, 300
+    chunks = 1747, 150
+    data = np.arange(np.prod(shape), dtype="u2").reshape(shape)
+
+    with h5py.File(tmp_path / "test_file.h5", "w") as f:
+        compression = hdf5plugin.Blosc2(cname='lz4', clevel=5, filters=hdf5plugin.Blosc2.SHUFFLE)
+        f.create_dataset('data', data=data, chunks=chunks, **compression)
+
+    with h5py.File(tmp_path / "test_file.h5", "r") as f:
+        yield f["data"]
+
+
+def test_B2Dataset(hdf5_test_dataset):
+    b2dataset = B2Dataset(hdf5_test_dataset)
+    assert b2dataset.is_b2_fast_access
+
+    # Access h5py.Dataset attribute
+    assert b2dataset.chunks == hdf5_test_dataset.chunks
+
+    # Access whole array
+    assert np.array_equal(b2dataset[()], hdf5_test_dataset[()])
+    # Unoptimized access
+    assert np.array_equal(b2dataset[::2], hdf5_test_dataset[::2])