from soundchanger.change import split_change
import pytest


def test_simple_change():
    assert split_change('a>b') == ('a', 'b', '', '')

def test_change_with_slash():
    assert split_change('a>b/') == ('a', 'b', '', '')

def test_change_with_environment():
    assert split_change('a>b/c_d') == ('a', 'b', 'c', 'd')

def test_change_with_environment_double_underscore():
    assert split_change('a>b/c__d') == ('a', 'b', 'c', 'd')

def test_change_with_environment_before():
    assert split_change('a>b/#_') == ('a', 'b', '#', '')

def test_change_with_environment_after():
    assert split_change('a>b/_#') == ('a', 'b', '', '#')

def test_change_with_empty_environment():
    assert split_change('a>b/_') == ('a', 'b', '', '')

def test_change_to_nothing():
    assert split_change('a>') == ('a', '', '', '')

def test_change_to_zero():
    assert split_change('a>-') == ('a', '-', '', '')

def test_invalid_input():
    with pytest.raises(ValueError):
        assert split_change('')