TST: Unit test data module load function

Unit test `data` module `load` function.

Author: jhlegarreta

test/test_data.py

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+# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
+# vi: set ft=python sts=4 ts=4 sw=4 et:
+#
+# Copyright The NiPreps Developers <[email protected]>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# We support and encourage derived works from this project, please read
+# about our expectations at
+#
+#     https://www.nipreps.org/community/licensing/
+#
+
+import h5py
+import nibabel as nb
+import numpy as np
+import pytest
+
+from nifreeze import data
+from nifreeze.data import dmri, pet
+
+
+def _raise_type(*args, **kwargs):
+    raise TypeError("Cannot read")
+
+
+def test_load_hdf5_error(monkeypatch, tmp_path):
+    fname = tmp_path / ("dataset" + data.NFDH5_EXT)
+
+    # All three dataclasses raise TypeError: load should raise TypeError
+    monkeypatch.setattr(
+        data.BaseDataset,
+        "from_filename",
+        classmethod(lambda _cls, fn: _raise_type()),
+        raising=False,
+    )
+    monkeypatch.setattr(
+        data.PET, "from_filename", classmethod(lambda _cls, fn: _raise_type()), raising=False
+    )
+    monkeypatch.setattr(
+        data.DWI, "from_filename", classmethod(lambda _cls, fn: _raise_type()), raising=False
+    )
+
+    with pytest.raises(TypeError, match="Could not read data"):
+        data.load(fname)
+
+
+@pytest.mark.parametrize(
+    "target, prior_failures",
+    [
+        (data.BaseDataset, []),
+        (data.PET, [data.BaseDataset]),
+        (data.DWI, [data.BaseDataset, data.PET]),
+    ],
+)
+def test_load_hdf5_sentinel(monkeypatch, tmp_path, target, prior_failures):
+    fname = tmp_path / ("dataset" + data.NFDH5_EXT)
+
+    sentinel = object()
+
+    # Force earlier readers to raise TypeError so load() will try the target
+    for cls in prior_failures:
+        monkeypatch.setattr(
+            cls, "from_filename", classmethod(lambda _cls, fn: _raise_type()), raising=False
+        )
+
+    # Make the target reader return our sentinel
+    monkeypatch.setattr(
+        target, "from_filename", classmethod(lambda _cls, fn: sentinel), raising=False
+    )
+
+    assert data.load(fname) is sentinel
+
+
+@pytest.mark.parametrize(
+    "target, prior_failures, vol_size",
+    [
+        (data.BaseDataset, [], (4, 5, 6, 2)),
+        (data.PET, [data.BaseDataset], (3, 4, 3, 5)),
+        (data.DWI, [data.BaseDataset, data.PET], (2, 2, 6, 4)),
+    ],
+)
+def test_load_hdf5_data(request, tmp_path, monkeypatch, target, prior_failures, vol_size):
+    """
+    For each target dataclass, write a tiny HDF5 file with random data, force
+    earlier readers to raise TypeError, and monkeypatch the target's
+    from_filename to read the HDF5 and return a small object containing the data
+    so we can assert it was read.
+    """
+
+    rng = request.node.rng
+
+    # Create random arrays to write into the HDF5 file
+    dataobj = rng.random(vol_size).astype(np.float32)
+    affine = np.eye(4).astype(np.float64)
+    brainmask_dataobj = rng.choice([True, False], size=dataobj.shape[:3]).astype(np.uint8)
+
+    fname = tmp_path / ("dataset" + data.NFDH5_EXT)
+
+    # Write a minimal HDF5 layout that our patched reader will understand
+    with h5py.File(fname, "w") as f:
+        f.create_dataset("dataobj", data=dataobj)
+        f.create_dataset("affine", data=affine)
+        f.create_dataset("brainmask", data=brainmask_dataobj)
+
+    # Force earlier readers to raise TypeError so load() will try the target
+    for cls in prior_failures:
+        monkeypatch.setattr(
+            cls, "from_filename", classmethod(lambda _cls, fn: _raise_type()), raising=False
+        )
+
+    # Define a reader that reads our HDF5 layout and returns a simple object
+    def _from_filename(filename):
+        with h5py.File(filename, "r") as _f:
+            _dataobj = np.array(_f["dataobj"])
+            _affine = np.array(_f["affine"])
+            _brainmask = np.array(_f["brainmask"]).astype(bool)
+
+        class SimpleBaseDataset:
+            def __init__(self, **kwargs):
+                self.dataobj = kwargs["dataobj"]
+                self.affine = kwargs["affine"]
+                self.brainmask = None
+
+        obj = SimpleBaseDataset()
+        # Mirror names that consumers expect
+        obj.dataobj = _dataobj
+        obj.affine = _affine
+        obj.brainmask = _brainmask
+        return obj
+
+    # Patch the target class's from_filename to use our reader
+    monkeypatch.setattr(
+        target,
+        "from_filename",
+        classmethod(lambda _cls, fn: _from_filename(fn)),
+        raising=False,
+    )
+
+    # Call the top-level loader and verify we got back the object with the data
+    retval = data.load(fname)
+
+    # The returned object should have the attributes we set above
+    assert hasattr(retval, "dataobj")
+    assert hasattr(retval, "affine")
+    assert hasattr(retval, "brainmask")
+
+    assert retval.dataobj is not None
+    assert retval.dataobj.shape == dataobj.shape
+    assert np.allclose(retval.dataobj, dataobj)
+
+    assert retval.affine is not None
+    assert retval.affine.shape == affine.shape
+    assert np.array_equal(retval.affine, affine)
+
+    assert retval.brainmask is not None
+    assert retval.brainmask.shape == brainmask_dataobj.shape
+    assert np.array_equal(retval.brainmask, brainmask_dataobj)
+
+
+@pytest.mark.random_uniform_spatial_data((5, 2, 4), 0.0, 1.0)
+@pytest.mark.random_uniform_spatial_data((2, 2, 2, 4), 0.0, 1.0)
+@pytest.mark.parametrize(
+    "use_brainmask, kwargs",
+    [
+        (True, {}),
+        (False, {"data": 2.0}),
+    ],
+)
+def test_load_base_nifti(
+    request, tmp_path, monkeypatch, setup_random_uniform_spatial_data, use_brainmask, kwargs
+):
+    rng = request.node.rng
+    dataobj, affine = setup_random_uniform_spatial_data
+    img = nb.Nifti1Image(dataobj, affine)
+    img_fname = tmp_path / "data.nii.gz"
+    nb.save(img, img_fname)
+
+    brainmask_dataobj = np.ones(dataobj.shape[:3]).astype(bool)
+    if use_brainmask:
+        brainmask_dataobj = rng.choice([True, False], size=dataobj.shape[:3]).astype(bool)
+
+    brainmask = nb.Nifti1Image(brainmask_dataobj.astype(np.uint8), affine)
+    brainmask_fname = tmp_path / "brainmask.nii.gz"
+    nb.save(brainmask, brainmask_fname)
+
+    # Monkeypatch BaseDataset to a minimal holder class that mirrors the API
+    class SimpleBaseDataset:
+        def __init__(self, **kwargs):
+            self.dataobj = kwargs["dataobj"]
+            self.affine = kwargs["affine"]
+            self.brainmask = None
+
+    monkeypatch.setattr(data, "BaseDataset", SimpleBaseDataset)
+
+    retval = data.load(img_fname, brainmask_file=brainmask_fname, **kwargs)
+
+    assert isinstance(retval, data.BaseDataset)
+
+    assert hasattr(retval, "dataobj")
+    assert hasattr(retval, "brainmask")
+    assert hasattr(retval, "affine")
+
+    assert retval.dataobj is not None
+    assert np.allclose(retval.dataobj, dataobj)
+
+    assert retval.affine is not None
+    assert np.allclose(retval.affine, affine)
+
+    assert retval.brainmask is not None
+    assert np.array_equal(retval.brainmask, brainmask_dataobj)
+
+
+def test_load_dmri_from_nii(monkeypatch, tmp_path):
+    fname = tmp_path / "image.nii"
+    mask = tmp_path / "mask.nii"
+
+    called = {}
+    sentinel = object()
+
+    def dummy_from_nii(filename, brainmask_file=None, **kwargs):
+        called["filename"] = filename
+        called["brainmask_file"] = brainmask_file
+        called["kwargs"] = kwargs
+        return sentinel
+
+    monkeypatch.setattr(dmri, "from_nii", dummy_from_nii)
+
+    res = data.load(fname, brainmask_file=mask, gradients_file="grad.txt", bvec_file="bvecs.txt")
+
+    assert res is sentinel
+    assert called["filename"] == fname
+    assert called["brainmask_file"] == mask
+    assert "gradients_file" in called["kwargs"]
+    assert (
+        "bvec_file" in called["kwargs"]
+        or "bvecs_file" in called["kwargs"]
+        or "bvecs" in called["kwargs"]
+    )
+
+
+def test_load_pet_from_nii(monkeypatch, tmp_path):
+    fname = tmp_path / "image.nii"
+    mask = tmp_path / "mask.nii"
+
+    called = {}
+    sentinel = object()
+
+    def dummy_from_nii(filename, brainmask_file=None, **kwargs):
+        called["filename"] = filename
+        called["brainmask_file"] = brainmask_file
+        called["kwargs"] = kwargs
+        return sentinel
+
+    monkeypatch.setattr(pet, "from_nii", dummy_from_nii)
+
+    retval = data.load(fname, brainmask_file=mask, temporal_file="temporal.txt")
+
+    assert retval is sentinel
+    assert called["filename"] == fname
+    assert called["brainmask_file"] == mask
+    assert "temporal_file" in called["kwargs"]