def test_clear(self):
pairs = [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
cache = LruCache(pairs)
self.assertEqual(len(cache), len(pairs))
cache.clear()
self.assertEqual(len(cache), 0)
cache.clear()
self.assertEqual(len(cache), 0)
cache.update(pairs)
self.assertEqual(len(cache), len(pairs))
cache.clear()
self.assertEqual(len(cache), 0)
def test_delitem(self):
with self.assertRaises(KeyError):
del LruCache()['key']
pairs = [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
cache = LruCache(pairs)
with self.assertRaises(KeyError):
del cache['key']
for index, (key, value) in enumerate(pairs):
del cache[key]
self.assertEqual(cache.items(), pairs[index+1:][::-1])
# start deleting from the tail
cache.update(pairs)
for index, (key, value) in enumerate(pairs[::-1]):
del cache[key]
index = len(pairs) - index - 1
self.assertEqual(cache.items(), pairs[:index][::-1])
