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import copy
import pytest
from babel import support
def test_proxy_caches_result_of_function_call():
counter = 0
def add_one():
nonlocal counter
counter += 1
return counter
proxy = support.LazyProxy(add_one)
assert proxy.value == 1
assert proxy.value == 1
def test_can_disable_proxy_cache():
counter = 0
def add_one():
nonlocal counter
counter += 1
return counter
proxy = support.LazyProxy(add_one, enable_cache=False)
assert proxy.value == 1
assert proxy.value == 2
@pytest.mark.parametrize(("copier", "expected_copy_value"), [
(copy.copy, 2),
(copy.deepcopy, 1),
])
def test_can_copy_proxy(copier, expected_copy_value):
numbers = [1, 2]
def first(xs):
return xs[0]
proxy = support.LazyProxy(first, numbers)
proxy_copy = copier(proxy)
numbers.pop(0)
assert proxy.value == 2
assert proxy_copy.value == expected_copy_value
def test_handle_attribute_error():
def raise_attribute_error():
raise AttributeError('message')
proxy = support.LazyProxy(raise_attribute_error)
with pytest.raises(AttributeError, match='message'):
_ = proxy.value
def test_lazy_proxy():
def greeting(name='world'):
return f"Hello, {name}!"
lazy_greeting = support.LazyProxy(greeting, name='Joe')
assert str(lazy_greeting) == "Hello, Joe!"
assert ' ' + lazy_greeting == ' Hello, Joe!'
assert '(%s)' % lazy_greeting == '(Hello, Joe!)'
assert f"[{lazy_greeting}]" == "[Hello, Joe!]"
greetings = sorted([
support.LazyProxy(greeting, 'world'),
support.LazyProxy(greeting, 'Joe'),
support.LazyProxy(greeting, 'universe'),
])
assert [str(g) for g in greetings] == [
"Hello, Joe!",
"Hello, universe!",
"Hello, world!",
]
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