from monai import transforms as trans
from monai.data.meta_tensor import MetaTensor

def test_monai_utils():

    # fake data
    x = np.ones((1, 64, 64, 64))

    # fake affines
    affine_1 = np.eye(4)
    affine_2 = np.eye(4) * 2

    resamp = trans.Spacing(pixdim=[1, 1, 1], diagonal=False, mode='bilinear')

    # using MetaTensor works as expected
    y_1 = resamp(MetaTensor(x, affine=affine_1))
    y_2 = resamp(MetaTensor(x, affine=affine_2))
    assert not all(i == j for i, j in zip(y_1.shape, y_2.shape))

    # using affine has no effect
    y_1 = resamp(x, affine=affine_1)
    y_2 = resamp(x, affine=affine_2)

    # these shapes should be different!
    assert not all(i == j for i, j in zip(y_1.shape, y_2.shape))