import pytest
import re
from soundchanger.change import apply

def test_error_in_change():
    with pytest.raises(ValueError, match=re.escape("Change  is not a valid sound change. (Missing character '>')")):
        apply('', '')

def test_error_split():
    with pytest.raises(ValueError, match=re.escape("Change a>b/c/d is not a valid sound change. (More than one '/' character)")):
        apply('a>b/c/d', '')

def test_error_in_environment():
    with pytest.raises(ValueError, match=re.escape("Environment c is not a valid environment. (Character '_' should exist exactly once)")):
        apply('a>b/c', '')

def test_no_change_from():
    with pytest.raises(ValueError, match=re.escape("Nothing to change from.")):
        apply('>b', '')