def test_layers_view():
    X = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
    L = np.array([[10, 11, 12], [13, 14, 15], [16, 17, 18]])
    real_adata = ad.AnnData(X)
    real_adata.layers["L"] = L
    view_adata = real_adata[1:, 1:]
    real_hash = joblib.hash(real_adata)
    view_hash = joblib.hash(view_adata)

    assert view_adata.is_view

    with pytest.raises(ValueError):
        view_adata.layers["L2"] = L + 2

    assert view_adata.is_view  # Failing to set layer item makes adata not view
    assert real_hash == joblib.hash(real_adata)
    assert view_hash == joblib.hash(view_adata)

    view_adata.layers["L2"] = L[1:, 1:] + 2

    assert not view_adata.is_view
    assert real_hash == joblib.hash(real_adata)
    assert view_hash != joblib.hash(view_adata)
def intersectmatchers(m1, m2):
    """Composes two matchers by matching if both of them match.

    The second matcher's non-matching-attributes (root, cwd, bad, traversedir)
    are ignored.
    """
    if m1 is None or m2 is None:
        return m1 or m2
    if m1.always():
        m = copy.copy(m2)
        # TODO: Consider encapsulating these things in a class so there's only
        # one thing to copy from m1.
        m.bad = m1.bad
        m.traversedir = m1.traversedir
        m.abs = m1.abs
        m.rel = m1.rel
        m._relativeuipath |= m1._relativeuipath
        return m
    if m2.always():
        m = copy.copy(m1)
        m._relativeuipath |= m2._relativeuipath
        return m
    return intersectionmatcher(m1, m2)