test_hdfio.py

import numpy as np
import pytest

import monetio.sat.hdfio as hdfio

filename = "test.hdf"
nx = 2
ny = 3
nz = 5
x = np.linspace(0, 1, nx, dtype=np.float64)
y = np.linspace(0, 1, ny, dtype=np.float64)
z = np.linspace(0, 1, nz, dtype=np.float64)
xfield, yfield, zfield = np.meshgrid(x, y, z, indexing="ij")
u = np.empty((nx, ny, nz), dtype=np.float32)
v = np.empty((nx, ny, nz), dtype=np.float32)
w = np.empty((nx, ny, nz), dtype=np.float32)
u[:, :, :] = 1
v[:, :, :] = xfield[:, :, :] * yfield[:, :, :] * zfield[:, :, :]
w[:, :, :] = xfield[:, :, :] ** 2 + yfield[:, :, :] ** 2


@pytest.fixture
def sample_file(tmp_path):
    fp = str(tmp_path / filename)
    fileid = hdfio.hdf_create(fp)
    hdfio.hdf_write_coord(fileid, "x", x)
    hdfio.hdf_write_coord(fileid, "y", y)
    hdfio.hdf_write_coord(fileid, "z", z)
    hdfio.hdf_write_field(fileid, "u", ("x", "y", "z"), u)
    hdfio.hdf_write_field(fileid, "v", ("x", "y", "z"), v)
    hdfio.hdf_write_field(fileid, "w", ("x", "y", "z"), w)
    hdfio.hdf_close(fileid)
    return fp


def test_hdf_list(sample_file):
    fileid = hdfio.hdf_open(sample_file)
    datasets, indices = hdfio.hdf_list(fileid)
    assert sorted(indices) == list(range(6))
    assert set(datasets) == {"x", "y", "z", "u", "v", "w"}
    hdfio.hdf_close(fileid)


def test_hdf_read(sample_file):
    fileid = hdfio.hdf_open(sample_file)
    u = hdfio.hdf_read(fileid, "u")
    v = hdfio.hdf_read(fileid, "v")
    w = hdfio.hdf_read(fileid, "w")
    np.testing.assert_equal(u, u)
    np.testing.assert_equal(v, v)
    np.testing.assert_equal(w, w)
    hdfio.hdf_close(fileid)


@pytest.fixture
def pyhdf_missing(monkeypatch):
    # http://materials-scientist.com/blog/2021/02/11/mocking-failing-module-import-python/
    import builtins
    import importlib
    import sys

    real_dunder_import = builtins.__import__
    real_importlib_import = importlib.import_module

    blocked_imports = {"pyhdf", "pyhdf.SD"}

    def wrapped_dunder_import(name, *args, **kwargs):
        if name in blocked_imports:
            raise ImportError(f"Mocked import error for {name!r}")
        return real_dunder_import(name, *args, **kwargs)

    def wrapped_importlib_import(name, *args, **kwargs):
        if name in blocked_imports:
            raise ImportError(f"Mocked import error for {name!r}")
        return real_importlib_import(name, *args, **kwargs)

    for mod in blocked_imports:
        monkeypatch.delitem(sys.modules, mod, raising=False)
    monkeypatch.delitem(sys.modules, "monetio.sat.hdfio", raising=False)  # important!
    monkeypatch.setattr(builtins, "__import__", wrapped_dunder_import)
    monkeypatch.setattr(importlib, "import_module", wrapped_importlib_import)


def test_pyhdf_missing_error(pyhdf_missing):
    with pytest.raises(RuntimeError, match="importing required module 'pyhdf.SD'"):
        import monetio.sat.hdfio  # noqa: F401