synapse/tests/util/test_itertools.py
Erik Johnston 1a08e0cdab
Fix event chain bg update. (#9118)
We passed in a graph to `sorted_topologically` which didn't have an
entry for each node (as we dropped nodes with no edges).
2021-01-14 18:57:32 +00:00

94 lines
3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2020 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Dict, List
from synapse.util.iterutils import chunk_seq, sorted_topologically
from tests.unittest import TestCase
class ChunkSeqTests(TestCase):
def test_short_seq(self):
parts = chunk_seq("123", 8)
self.assertEqual(
list(parts), ["123"],
)
def test_long_seq(self):
parts = chunk_seq("abcdefghijklmnop", 8)
self.assertEqual(
list(parts), ["abcdefgh", "ijklmnop"],
)
def test_uneven_parts(self):
parts = chunk_seq("abcdefghijklmnop", 5)
self.assertEqual(
list(parts), ["abcde", "fghij", "klmno", "p"],
)
def test_empty_input(self):
parts = chunk_seq([], 5)
self.assertEqual(
list(parts), [],
)
class SortTopologically(TestCase):
def test_empty(self):
"Test that an empty graph works correctly"
graph = {} # type: Dict[int, List[int]]
self.assertEqual(list(sorted_topologically([], graph)), [])
def test_handle_empty_graph(self):
"Test that a graph where a node doesn't have an entry is treated as empty"
graph = {} # type: Dict[int, List[int]]
# For disconnected nodes the output is simply sorted.
self.assertEqual(list(sorted_topologically([1, 2], graph)), [1, 2])
def test_disconnected(self):
"Test that a graph with no edges work"
graph = {1: [], 2: []} # type: Dict[int, List[int]]
# For disconnected nodes the output is simply sorted.
self.assertEqual(list(sorted_topologically([1, 2], graph)), [1, 2])
def test_linear(self):
"Test that a simple `4 -> 3 -> 2 -> 1` graph works"
graph = {1: [], 2: [1], 3: [2], 4: [3]} # type: Dict[int, List[int]]
self.assertEqual(list(sorted_topologically([4, 3, 2, 1], graph)), [1, 2, 3, 4])
def test_subset(self):
"Test that only sorting a subset of the graph works"
graph = {1: [], 2: [1], 3: [2], 4: [3]} # type: Dict[int, List[int]]
self.assertEqual(list(sorted_topologically([4, 3], graph)), [3, 4])
def test_fork(self):
"Test that a forked graph works"
graph = {1: [], 2: [1], 3: [1], 4: [2, 3]} # type: Dict[int, List[int]]
# Valid orderings are `[1, 3, 2, 4]` or `[1, 2, 3, 4]`, but we should
# always get the same one.
self.assertEqual(list(sorted_topologically([4, 3, 2, 1], graph)), [1, 2, 3, 4])