def test_name_once():
var = EnvVar()
assert not var.name
var.name = 'FOO'
assert var.name == 'FOO'
with pytest.raises(AssertionError) as e:
var.name = 'BAR'
assert str(e.value) == 'EnvVar name is immutable once set'
def test_name_mixed_case_error():
var = EnvVar()
with pytest.raises(AssertionError) as e:
var.name = 'foo'
assert str(e.value) == 'EnvVar name must be uppercase'