def test_decorator():
""" Calling the lazy object will call function's return value """
fn = mock.Mock()
lazy_fn = lazy(fn)
val = lazy_fn()
assert fn.called == False, "Should not be called before value is accessed"
assert isinstance(val, Lazy), "Return value should be a Lazy instance"
def test_lazy_class():
fn = mock.Mock()
fn.return_value = 1 # int
lazy_fn = lazy(fn)
lazy_obj = lazy_fn()
assert isinstance(lazy_obj, int)
fn.return_value = 'str' # str
assert isinstance(lazy_obj, str)
def test_caching_vs_noncaching():
""" Testing use of different Lazy classes """
fn1 = mock.Mock()
fn2 = mock.Mock()
lazy_fn = lazy(fn1)
lazy_caching_fn = lazy(fn2, CachingLazy)
val1 = lazy_fn()
val1._eval()
val1._eval()
val1._eval()
val2 = lazy_caching_fn()
val2._eval()
val2._eval()
val2._eval()
assert fn1.call_count == 3, "Expected 3 calls, got %s" % fn1.call_count
assert fn2.call_count == 1, "Expected one call, got %s" % fn2.call_count
assert isinstance(val1, Lazy), "Expected Lazy instance"
assert isinstance(val2, CachingLazy), "Expected CachingLazy instance"
def test_methods():
fn = mock.Mock()
fn.return_value = 'foobar'
lazy_fn = lazy(fn)
lazy_obj = lazy_fn()
assert lazy_obj.replace('bar', 'foo') == 'foofoo'
def test_subscript():
fn = mock.Mock()
fn.return_value = 'foo'
lazy_fn = lazy(fn)
lazy_obj = lazy_fn()
assert lazy_obj[:2] == 'fo'
def test_decorator_with_kwargs():
fn = mock.Mock()
fn.return_value = 'foo'
lazy_fn = lazy(fn)
lazy_fn(1, 2, foo=3)._eval()
fn.assert_called_once_with(1, 2, foo=3)
def test_call():
""" Calling the lazy object """
fn, lazy = get_lazy()
lazy()
fn.return_value.assert_called_once()