async def test_map_as():
async def map_op(value):
return value * 2
assert [value async for value in a.map(map_op, range(5))] == list(range(0, 10, 2))
assert [
value async for value in a.map(hide_coroutine(map_op), range(5, 10, 2))
] == list(range(10, 20, 4))
async def test_map_sa():
def map_op(value):
return value * 2
assert [value async for value in a.map(map_op, asyncify(range(5)))] == list(
range(0, 10, 2)
)
assert [value async for value in a.map(map_op, asyncify(range(5, 10, 2)))] == list(
range(10, 20, 4)
)
async def test_exit_stack_pop_all():
async with a.ExitStack() as exit_stack:
contexts = list(
map(lambda v: MockAsyncContext(v) if v % 2 else MockContext(v),
range(10)))
values = await a.list(a.map(exit_stack.enter_context, contexts))
assert values == list(range(10))
assert all(cm.entered for cm in contexts)
assert all(not cm.exited for cm in contexts)
clone_stack = exit_stack.pop_all()
assert all(not cm.exited for cm in contexts)
await clone_stack.aclose()
assert all(cm.exited for cm in contexts)
async def test_mock_backend_example(self) -> None:
# This is an example of a backend system.
# This test demonstrates how contracts can be used with coroutines.
async def has_author(identifier: str) -> bool:
return identifier in ["Margaret Cavendish", "Jane Austen"]
async def has_category(category: str) -> bool:
return category in await get_categories()
async def get_categories() -> List[str]:
return ["sci-fi", "romance"]
@dataclasses.dataclass
class Book:
identifier: str
author: str
@icontract.require(lambda categories: a.map(has_category, categories))
@icontract.ensure(lambda result: a.all(
a.await_each(has_author(book.author) for book in result)))
async def list_books(categories: List[str]) -> List[Book]:
result = [] # type: List[Book]
for category in categories:
if category == "sci-fi":
result.extend([
Book(identifier="The Blazing World",
author="Margaret Cavendish")
])
elif category == "romance":
result.extend([
Book(identifier="Pride and Prejudice",
author="Jane Austen")
])
else:
raise AssertionError(category)
return result
sci_fi_books = await list_books(categories=['sci-fi'])
self.assertListEqual(['The Blazing World'],
[book.identifier for book in sci_fi_books])