def test_update_one():
crdt = CRDT()
crdt.add('a', 1)
crdt.update('a', 'b')
assert len(crdt.log) == 2
assert crdt.data == {'b': 1}
assert crdt.log[1].op == UPDATE
def test_update_key_collision():
crdt = CRDT()
crdt.add('a', 1)
crdt.add('b', 2)
crdt.update('a', 'b')
# In this implementation of LWW the update should overwrite the original key if the key already exists
assert crdt.data == {'b': 1}
def test_merge_update_key_collision():
crdt_1, crdt_2 = CRDT(), CRDT()
crdt_1.add('a', 1)
crdt_2.add('b', 2)
crdt_1.update('a', 'b')
merged = merge(crdt_1, crdt_2)
# In this implementation of LWW the update should overwrite the original key if the key already exists
assert merged.data == {'b': 1}
def test_update_many(ans, upd):
crdt = CRDT()
for k, v in ans.items():
crdt.add(k, v)
for k, v in upd.items():
crdt.update(k, v)
# The keys are added then updated, the length of the log should be the sum of the lengths of the ans and upd set
assert len(crdt.log) == len(ans) + len(upd)
assert crdt.data == {upd[k]:v for k, v in ans.items()}
def test_merge_update_same_key_twice():
crdt_1, crdt_2 = CRDT(), CRDT()
crdt_1.add('a', 1)
crdt_2.add('a', 2)
crdt_1.update('a', 'b')
crdt_2.update('a', 'c')
merged = merge(crdt_1, crdt_2)
# In a LWW merge, only the latest update should be present
assert merged.data == {'c': 2}
def test_update_after_remove():
crdt = CRDT()
crdt.add('a', 1)
try:
crdt.update('a', 'b')
crdt.remove('a')
# In the same instance, this operation should fail
assert False
except KeyError:
pass
def test_merge_add_update_remove(ans, upd):
crdt_1, crdt_2 = CRDT(), CRDT()
ans_1, ans_2 = slice_dict(ans, 0, len(ans) // 2), slice_dict(ans, len(ans) // 2, len(ans))
for k, v in ans.items():
crdt_1.add(k, v)
crdt_2.add(k, v)
# Update the elements in the second half of the ans set in crdt_1 (opposite of test_merge_add_remove_update())
for k in ans_2:
crdt_1.update(k, upd[k])
# Remove old keys that are updated in crdt_1 in crdt_2 (opposite of test_merge_add_remove_update())
for k in ans_2:
crdt_2.remove(k)
merged = merge(crdt_1, crdt_2)
# Since this is a LWW set, the **removes** will overwrite the **updates** since they're executed later
assert merged.data == ans_1