Saving and loading in JSON

A Laminate saved with save_json() is loaded identical by load_json(), from a file name or a file object, see Saving and loading (JSON). The function make_laminate of the tests creates a laminate with laminated_plate():

def test_save_load(tmp_path):
    lam = make_laminate()
    fname = tmp_path / 'laminate.json'
    save_json(lam, fname)
    assert_same(lam, load_json(fname))
    assert_same(lam, load_json(str(fname)))
    with open(fname) as f:
        assert json.load(f)['type'] == 'Laminate'
    buf = io.StringIO()
    save_json(lam, buf, indent=None)
    assert '\n' not in buf.getvalue()
    buf.seek(0)
    assert_same(lam, load_json(buf))

to_dict() and from_dict() embed a laminate in another JSON document:

def test_example_embed_in_json_document(tmp_path):
    lam = laminated_plate([0, 45, -45, 90], plyt=0.125e-3,
                          laminaprop=laminaprop, rho=1600.)
    # to_dict returns JSON types, to be embedded in another JSON document
    doc = {'name': 'skin', 'mesh_size': 0.01, 'laminate': to_dict(lam)}
    fname = tmp_path / 'model.json'
    with open(fname, 'w') as f:
        json.dump(doc, f)
    with open(fname) as f:
        doc2 = json.load(f)
    lam2 = from_dict(doc2['laminate'])
    np.testing.assert_array_equal(lam2.ABD, lam.ABD)
    np.testing.assert_array_equal(lam2.Ats, lam.Ats)
    assert lam2.intrhoz6 == lam.intrhoz6