def test_etype_str_to_tuple():
    """Convert etype from string to tuple."""
    # Test for expected input.
    c_etype_str = "user:like:item"
    c_etype = gb.etype_str_to_tuple(c_etype_str)
    assert c_etype == ("user", "like", "item")

    # Test for unexpected input: string with wrong format.
    c_etype_str = "user:like"
    with pytest.raises(
        AssertionError,
        match=re.escape(
            "Passed-in canonical etype should be in format of 'str:str:str'. "
            "But got user:like."
        ),
    ):
        _ = gb.etype_str_to_tuple(c_etype_str)
Convert etype from string to tuple.
tests/python/pytorch/graphbolt/test_base.py