def test_simple_addition():
assert evaluate('1 + 2') == 3
def test_literal():
assert evaluate('42') == 42
def test_error_eof():
with pytest.raises(SyntaxError) as excinfo:
evaluate('1 +')
assert excinfo.value.args[0] == 'unexpected end of source'
def test_error_null_src():
assert evaluate(' ') is None
def test_error_plus():
with pytest.raises(SyntaxError) as excinfo:
evaluate('+')
assert excinfo.value.args[0] == "unexpected '+' in line:\n+"
def test_long_addition():
assert evaluate('1 + 2 + 3 + 4 + 5') == 15
