Switch to ruff instead of flake8. (#14633)

ruff is a flake8-compatible Python linter written in Rust.
It supports the flake8 plugins that we use and is significantly
faster in testing.

.flake8

-# TODO: incorporate this into pyproject.toml if flake8 supports it in the future.
-# See https://github.com/PyCQA/flake8/issues/234
-[flake8]
-# see https://pycodestyle.readthedocs.io/en/latest/intro.html#error-codes
-# for error codes. The ones we ignore are:
-#  W503: line break before binary operator
-#  W504: line break after binary operator
-#  E203: whitespace before ':' (which is contrary to pep8?)
-#  E731: do not assign a lambda expression, use a def
-#  E501: Line too long (black enforces this for us)
-#
-# flake8-bugbear runs extra checks. Its error codes are described at
-# https://github.com/PyCQA/flake8-bugbear#list-of-warnings
-#  B019: Use of functools.lru_cache or functools.cache on methods can lead to memory leaks
-#  B023: Functions defined inside a loop must not use variables redefined in the loop
-#  B024: Abstract base class with no abstract method.
-
-ignore=W503,W504,E203,E731,E501,B019,B023,B024

.github/workflows/tests.yml

@@ -53,7 +53,7 @@ jobs:
       - run: scripts-dev/check_schema_delta.py --force-colors
 
   lint:
-    uses: "matrix-org/backend-meta/.github/workflows/python-poetry-ci.yml@v1"
+    uses: "matrix-org/backend-meta/.github/workflows/python-poetry-ci.yml@v2"
     with:
       typechecking-extras: "all"
 

changelog.d/14633.misc

+Use [ruff](https://github.com/charliermarsh/ruff/) instead of flake8.

poetry.lock

@@ -244,47 +244,6 @@ python-versions = ">=3.7"
 [package.extras]
 dev = ["Sphinx", "coverage", "flake8", "lxml", "memory-profiler", "mypy (==0.910)", "tox", "xmlschema (>=1.8.0)"]
 
-[[package]]
-name = "flake8"
-version = "5.0.4"
-description = "the modular source code checker: pep8 pyflakes and co"
-category = "dev"
-optional = false
-python-versions = ">=3.6.1"
-
-[package.dependencies]
-importlib-metadata = {version = ">=1.1.0,<4.3", markers = "python_version < \"3.8\""}
-mccabe = ">=0.7.0,<0.8.0"
-pycodestyle = ">=2.9.0,<2.10.0"
-pyflakes = ">=2.5.0,<2.6.0"
-
-[[package]]
-name = "flake8-bugbear"
-version = "22.12.6"
-description = "A plugin for flake8 finding likely bugs and design problems in your program. Contains warnings that don't belong in pyflakes and pycodestyle."
-category = "dev"
-optional = false
-python-versions = ">=3.7"
-
-[package.dependencies]
-attrs = ">=19.2.0"
-flake8 = ">=3.0.0"
-
-[package.extras]
-dev = ["coverage", "hypothesis", "hypothesmith (>=0.2)", "pre-commit", "tox"]
-
-[[package]]
-name = "flake8-comprehensions"
-version = "3.10.1"
-description = "A flake8 plugin to help you write better list/set/dict comprehensions."
-category = "dev"
-optional = false
-python-versions = ">=3.7"
-
-[package.dependencies]
-flake8 = ">=3.0,<3.2.0 || >3.2.0"
-importlib-metadata = {version = "*", markers = "python_version < \"3.8\""}
-
 [[package]]
 name = "frozendict"
 version = "2.3.4"
@@ -553,14 +512,6 @@ Twisted = ">=15.1.0"
 [package.extras]
 dev = ["black (==22.3.0)", "flake8 (==4.0.1)", "isort (==5.9.3)", "ldaptor", "matrix-synapse", "mypy (==0.910)", "tox", "types-setuptools"]
 
-[[package]]
-name = "mccabe"
-version = "0.7.0"
-description = "McCabe checker, plugin for flake8"
-category = "dev"
-optional = false
-python-versions = ">=3.6"
-
 [[package]]
 name = "msgpack"
 version = "1.0.4"
@@ -770,14 +721,6 @@ python-versions = "*"
 [package.dependencies]
 pyasn1 = ">=0.4.6,<0.5.0"
 
-[[package]]
-name = "pycodestyle"
-version = "2.9.1"
-description = "Python style guide checker"
-category = "dev"
-optional = false
-python-versions = ">=3.6"
-
 [[package]]
 name = "pycparser"
 version = "2.21"
@@ -801,14 +744,6 @@ typing-extensions = ">=4.1.0"
 dotenv = ["python-dotenv (>=0.10.4)"]
 email = ["email-validator (>=1.0.3)"]
 
-[[package]]
-name = "pyflakes"
-version = "2.5.0"
-description = "passive checker of Python programs"
-category = "dev"
-optional = false
-python-versions = ">=3.6"
-
 [[package]]
 name = "pygithub"
 version = "1.57"
@@ -1044,6 +979,14 @@ typing-extensions = {version = ">=4.0.0,<5.0", markers = "python_version < \"3.9
 [package.extras]
 jupyter = ["ipywidgets (>=7.5.1,<8.0.0)"]
 
+[[package]]
+name = "ruff"
+version = "0.0.189"
+description = "An extremely fast Python linter, written in Rust."
+category = "dev"
+optional = false
+python-versions = ">=3.7"
+
 [[package]]
 name = "secretstorage"
 version = "3.3.1"
@@ -1635,7 +1578,7 @@ user-search = ["pyicu"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.7.1"
-content-hash = "f20007013f33bc35a01e412c48adc62a936030f3074e06286674c5ad7f44d300"
+content-hash = "d20b6aea682a74e6a161080bb459e73160b8eb79526f5d17a525639ac3fe3e9e"
 
 [metadata.files]
 attrs = [
@@ -1827,18 +1770,6 @@ elementpath = [
     {file = "elementpath-2.5.0-py3-none-any.whl", hash = "sha256:2a432775e37a19e4362443078130a7dbfc457d7d093cd421c03958d9034cc08b"},
     {file = "elementpath-2.5.0.tar.gz", hash = "sha256:3a27aaf3399929fccda013899cb76d3ff111734abf4281e5f9d3721ba0b9ffa3"},
 ]
-flake8 = [
-    {file = "flake8-5.0.4-py2.py3-none-any.whl", hash = "sha256:7a1cf6b73744f5806ab95e526f6f0d8c01c66d7bbe349562d22dfca20610b248"},
-    {file = "flake8-5.0.4.tar.gz", hash = "sha256:6fbe320aad8d6b95cec8b8e47bc933004678dc63095be98528b7bdd2a9f510db"},
-]
-flake8-bugbear = [
-    {file = "flake8-bugbear-22.12.6.tar.gz", hash = "sha256:4cdb2c06e229971104443ae293e75e64c6107798229202fbe4f4091427a30ac0"},
-    {file = "flake8_bugbear-22.12.6-py3-none-any.whl", hash = "sha256:b69a510634f8a9c298dfda2b18a8036455e6b19ecac4fe582e4d7a0abfa50a30"},
-]
-flake8-comprehensions = [
-    {file = "flake8-comprehensions-3.10.1.tar.gz", hash = "sha256:412052ac4a947f36b891143430fef4859705af11b2572fbb689f90d372cf26ab"},
-    {file = "flake8_comprehensions-3.10.1-py3-none-any.whl", hash = "sha256:d763de3c74bc18a79c039a7ec732e0a1985b0c79309ceb51e56401ad0a2cd44e"},
-]
 frozendict = [
     {file = "frozendict-2.3.4-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:4a3b32d47282ae0098b9239a6d53ec539da720258bd762d62191b46f2f87c5fc"},
     {file = "frozendict-2.3.4-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:84c9887179a245a66a50f52afa08d4d92ae0f269839fab82285c70a0fa0dd782"},
@@ -2046,6 +1977,7 @@ lxml = [
     {file = "lxml-4.9.2-cp35-cp35m-manylinux_2_5_i686.manylinux1_i686.whl", hash = "sha256:ca989b91cf3a3ba28930a9fc1e9aeafc2a395448641df1f387a2d394638943b0"},
     {file = "lxml-4.9.2-cp35-cp35m-manylinux_2_5_x86_64.manylinux1_x86_64.whl", hash = "sha256:822068f85e12a6e292803e112ab876bc03ed1f03dddb80154c395f891ca6b31e"},
     {file = "lxml-4.9.2-cp35-cp35m-win32.whl", hash = "sha256:be7292c55101e22f2a3d4d8913944cbea71eea90792bf914add27454a13905df"},
+    {file = "lxml-4.9.2-cp35-cp35m-win_amd64.whl", hash = "sha256:998c7c41910666d2976928c38ea96a70d1aa43be6fe502f21a651e17483a43c5"},
     {file = "lxml-4.9.2-cp36-cp36m-macosx_10_15_x86_64.whl", hash = "sha256:b26a29f0b7fc6f0897f043ca366142d2b609dc60756ee6e4e90b5f762c6adc53"},
     {file = "lxml-4.9.2-cp36-cp36m-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_24_i686.whl", hash = "sha256:ab323679b8b3030000f2be63e22cdeea5b47ee0abd2d6a1dc0c8103ddaa56cd7"},
     {file = "lxml-4.9.2-cp36-cp36m-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:689bb688a1db722485e4610a503e3e9210dcc20c520b45ac8f7533c837be76fe"},
@@ -2055,6 +1987,7 @@ lxml = [
     {file = "lxml-4.9.2-cp36-cp36m-musllinux_1_1_aarch64.whl", hash = "sha256:58bfa3aa19ca4c0f28c5dde0ff56c520fbac6f0daf4fac66ed4c8d2fb7f22e74"},
     {file = "lxml-4.9.2-cp36-cp36m-musllinux_1_1_x86_64.whl", hash = "sha256:bc718cd47b765e790eecb74d044cc8d37d58562f6c314ee9484df26276d36a38"},
     {file = "lxml-4.9.2-cp36-cp36m-win32.whl", hash = "sha256:d5bf6545cd27aaa8a13033ce56354ed9e25ab0e4ac3b5392b763d8d04b08e0c5"},
+    {file = "lxml-4.9.2-cp36-cp36m-win_amd64.whl", hash = "sha256:3ab9fa9d6dc2a7f29d7affdf3edebf6ece6fb28a6d80b14c3b2fb9d39b9322c3"},
     {file = "lxml-4.9.2-cp37-cp37m-macosx_10_15_x86_64.whl", hash = "sha256:05ca3f6abf5cf78fe053da9b1166e062ade3fa5d4f92b4ed688127ea7d7b1d03"},
     {file = "lxml-4.9.2-cp37-cp37m-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_24_i686.whl", hash = "sha256:a5da296eb617d18e497bcf0a5c528f5d3b18dadb3619fbdadf4ed2356ef8d941"},
     {file = "lxml-4.9.2-cp37-cp37m-manylinux_2_17_aarch64.manylinux2014_aarch64.manylinux_2_24_aarch64.whl", hash = "sha256:04876580c050a8c5341d706dd464ff04fd597095cc8c023252566a8826505726"},
@@ -2147,10 +2080,6 @@ matrix-synapse-ldap3 = [
     {file = "matrix-synapse-ldap3-0.2.2.tar.gz", hash = "sha256:b388d95693486eef69adaefd0fd9e84463d52fe17b0214a00efcaa669b73cb74"},
     {file = "matrix_synapse_ldap3-0.2.2-py3-none-any.whl", hash = "sha256:66ee4c85d7952c6c27fd04c09cdfdf4847b8e8b7d6a7ada6ba1100013bda060f"},
 ]
-mccabe = [
-    {file = "mccabe-0.7.0-py2.py3-none-any.whl", hash = "sha256:6c2d30ab6be0e4a46919781807b4f0d834ebdd6c6e3dca0bda5a15f863427b6e"},
-    {file = "mccabe-0.7.0.tar.gz", hash = "sha256:348e0240c33b60bbdf4e523192ef919f28cb2c3d7d5c7794f74009290f236325"},
-]
 msgpack = [
     {file = "msgpack-1.0.4-cp310-cp310-macosx_10_9_universal2.whl", hash = "sha256:4ab251d229d10498e9a2f3b1e68ef64cb393394ec477e3370c457f9430ce9250"},
     {file = "msgpack-1.0.4-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:112b0f93202d7c0fef0b7810d465fde23c746a2d482e1e2de2aafd2ce1492c88"},
@@ -2370,10 +2299,6 @@ pyasn1-modules = [
     {file = "pyasn1-modules-0.2.8.tar.gz", hash = "sha256:905f84c712230b2c592c19470d3ca8d552de726050d1d1716282a1f6146be65e"},
     {file = "pyasn1_modules-0.2.8-py2.py3-none-any.whl", hash = "sha256:a50b808ffeb97cb3601dd25981f6b016cbb3d31fbf57a8b8a87428e6158d0c74"},
 ]
-pycodestyle = [
-    {file = "pycodestyle-2.9.1-py2.py3-none-any.whl", hash = "sha256:d1735fc58b418fd7c5f658d28d943854f8a849b01a5d0a1e6f3f3fdd0166804b"},
-    {file = "pycodestyle-2.9.1.tar.gz", hash = "sha256:2c9607871d58c76354b697b42f5d57e1ada7d261c261efac224b664affdc5785"},
-]
 pycparser = [
     {file = "pycparser-2.21-py2.py3-none-any.whl", hash = "sha256:8ee45429555515e1f6b185e78100aea234072576aa43ab53aefcae078162fca9"},
     {file = "pycparser-2.21.tar.gz", hash = "sha256:e644fdec12f7872f86c58ff790da456218b10f863970249516d60a5eaca77206"},
@@ -2416,10 +2341,6 @@ pydantic = [
     {file = "pydantic-1.10.2-py3-none-any.whl", hash = "sha256:1b6ee725bd6e83ec78b1aa32c5b1fa67a3a65badddde3976bca5fe4568f27709"},
     {file = "pydantic-1.10.2.tar.gz", hash = "sha256:91b8e218852ef6007c2b98cd861601c6a09f1aa32bbbb74fab5b1c33d4a1e410"},
 ]
-pyflakes = [
-    {file = "pyflakes-2.5.0-py2.py3-none-any.whl", hash = "sha256:4579f67d887f804e67edb544428f264b7b24f435b263c4614f384135cea553d2"},
-    {file = "pyflakes-2.5.0.tar.gz", hash = "sha256:491feb020dca48ccc562a8c0cbe8df07ee13078df59813b83959cbdada312ea3"},
-]
 pygithub = [
     {file = "PyGithub-1.57-py3-none-any.whl", hash = "sha256:5822febeac2391f1306c55a99af2bc8f86c8bf82ded000030cd02c18f31b731f"},
     {file = "PyGithub-1.57.tar.gz", hash = "sha256:c273f252b278fb81f1769505cc6921bdb6791e1cebd6ac850cc97dad13c31ff3"},
@@ -2560,6 +2481,24 @@ rich = [
     {file = "rich-12.6.0-py3-none-any.whl", hash = "sha256:a4eb26484f2c82589bd9a17c73d32a010b1e29d89f1604cd9bf3a2097b81bb5e"},
     {file = "rich-12.6.0.tar.gz", hash = "sha256:ba3a3775974105c221d31141f2c116f4fd65c5ceb0698657a11e9f295ec93fd0"},
 ]
+ruff = [
+    {file = "ruff-0.0.189-py3-none-macosx_10_7_x86_64.whl", hash = "sha256:07c947b42d3c5efc6761214acdb6b71a49b833ad9fb9b320454244a6fe01f212"},
+    {file = "ruff-0.0.189-py3-none-macosx_10_9_x86_64.macosx_11_0_arm64.macosx_10_9_universal2.whl", hash = "sha256:76e6161d021bde5738bf9d123ae445cb3a22fa60f14958ce64961d8af16141a0"},
+    {file = "ruff-0.0.189-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:c27f51e5b48cd483459cdd1c95a6bd989adcf7653ccc440ca437f4993fe4b812"},
+    {file = "ruff-0.0.189-py3-none-manylinux_2_17_armv7l.manylinux2014_armv7l.whl", hash = "sha256:e89f488a16ce2b21d940fc6271ed161affec788955f7b41761a9693a92e994bb"},
+    {file = "ruff-0.0.189-py3-none-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:fee593d8d470811c316ff2eb0124ac74668a3d637ab3fb237aa3fa8561fb89aa"},
+    {file = "ruff-0.0.189-py3-none-manylinux_2_17_ppc64.manylinux2014_ppc64.whl", hash = "sha256:bc3a73683a5b3b4b7bf951bbd4aa7d79b993c8c2e608a68de120c342ebe510f2"},
+    {file = "ruff-0.0.189-py3-none-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl", hash = "sha256:e5d73877558651f48c86d958afe0f662b6c3639990c230a6b9d82ac6093484db"},
+    {file = "ruff-0.0.189-py3-none-manylinux_2_17_s390x.manylinux2014_s390x.whl", hash = "sha256:3d1e6e9813f59ba54e7cb6f28c1f2a9a756197f6e321bd68519afe57f8522fce"},
+    {file = "ruff-0.0.189-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:8d177090cf03004b14814b0aad530758f5186d391250afb737570edd55beabc6"},
+    {file = "ruff-0.0.189-py3-none-musllinux_1_2_aarch64.whl", hash = "sha256:48de3253856a0a85f9b53a0ca1982946c7fd343c796cdc76ece0ae359d5b71b5"},
+    {file = "ruff-0.0.189-py3-none-musllinux_1_2_armv7l.whl", hash = "sha256:e935bb5a213030de312ad00df477f38c78ac97af58b0e6a4ae5762705a5113da"},
+    {file = "ruff-0.0.189-py3-none-musllinux_1_2_i686.whl", hash = "sha256:bdb8173d6efff96e0cc5fe38f5fc4daa0d28fb11553482b9989d372fdafc7708"},
+    {file = "ruff-0.0.189-py3-none-musllinux_1_2_x86_64.whl", hash = "sha256:14486fd8632bc4c7f926137a9c6a8c45993ff6667ddb7a88192c369c3afd86e9"},
+    {file = "ruff-0.0.189-py3-none-win32.whl", hash = "sha256:e281080e2ed04f01275b3df5baa0afe2802ab145349298e24700cdd09c0afddc"},
+    {file = "ruff-0.0.189-py3-none-win_amd64.whl", hash = "sha256:c552ff0b0587a5e13f935131d2a19782c0baf8b59175cf3160a76545fbdbdd76"},
+    {file = "ruff-0.0.189.tar.gz", hash = "sha256:90a3031461ed83686ff78f96e58d28cdee835110c51bdfa0968a2d5892610c71"},
+]
 secretstorage = [
     {file = "SecretStorage-3.3.1-py3-none-any.whl", hash = "sha256:422d82c36172d88d6a0ed5afdec956514b189ddbfb72fefab0c8a1cee4eaf71f"},
     {file = "SecretStorage-3.3.1.tar.gz", hash = "sha256:fd666c51a6bf200643495a04abb261f83229dcb6fd8472ec393df7ffc8b6f195"},

pyproject.toml

@@ -40,6 +40,46 @@ target-version = ['py37', 'py38', 'py39', 'py310']
 # https://black.readthedocs.io/en/stable/usage_and_configuration/file_collection_and_discovery.html#gitignore
 # Use `extend-exclude` if you want to exclude something in addition to this.
 
+[tool.ruff]
+line-length = 88
+
+# See https://github.com/charliermarsh/ruff/#pycodestyle
+# for error codes. The ones we ignore are:
+#  E731: do not assign a lambda expression, use a def
+#  E501: Line too long (black enforces this for us)
+#
+# See https://github.com/charliermarsh/ruff/#pyflakes
+#  F401: unused import
+#  F811: Redefinition of unused
+#  F821: Undefined name
+#
+# flake8-bugbear compatible checks. Its error codes are described at
+# https://github.com/charliermarsh/ruff/#flake8-bugbear
+#  B019: Use of functools.lru_cache or functools.cache on methods can lead to memory leaks
+#  B023: Functions defined inside a loop must not use variables redefined in the loop
+#  B024: Abstract base class with no abstract method.
+ignore = [
+    "B019",
+    "B023",
+    "B024",
+    "E501",
+    "E731",
+    "F401",
+    "F811",
+    "F821",
+]
+select = [
+    # pycodestyle checks.
+    "E",
+    "W",
+    # pyflakes checks.
+    "F",
+    # flake8-bugbear checks.
+    "B0",
+    # flake8-comprehensions checks.
+    "C4",
+]
+
 [tool.isort]
 line_length = 88
 sections = ["FUTURE", "STDLIB", "THIRDPARTY", "TWISTED", "FIRSTPARTY", "TESTS", "LOCALFOLDER"]
@@ -274,12 +314,10 @@ all = [
 ]
 
 [tool.poetry.dev-dependencies]
-## We pin black so that our tests don't start failing on new releases.
+# We pin black so that our tests don't start failing on new releases.
 isort = ">=5.10.1"
 black = ">=22.3.0"
-flake8-comprehensions = "*"
-flake8-bugbear = ">=21.3.2"
-flake8 = "*"
+ruff = "0.0.189"
 
 # Typechecking
 mypy = "*"

scripts-dev/lint.sh

 #!/usr/bin/env bash
 #
 # Runs linting scripts over the local Synapse checkout
-# isort - sorts import statements
 # black - opinionated code formatter
-# flake8 - lints and finds mistakes
+# ruff - lints and finds mistakes
 
 set -e
 
@@ -105,6 +104,6 @@ set -x
 isort "${files[@]}"
 python3 -m black "${files[@]}"
 ./scripts-dev/config-lint.sh
-flake8 "${files[@]}"
+ruff "${files[@]}"
 ./scripts-dev/check_pydantic_models.py lint
 mypy

stubs/frozendict.pyi

@@ -14,6 +14,8 @@
 
 # Stub for frozendict.
 
+from __future__ import annotations
+
 from typing import Any, Hashable, Iterable, Iterator, Mapping, Tuple, TypeVar, overload
 
 _KT = TypeVar("_KT", bound=Hashable)  # Key type.

stubs/icu.pyi

@@ -14,6 +14,8 @@
 
 # Stub for PyICU.
 
+from __future__ import annotations
+
 class Locale:
     @staticmethod
     def getDefault() -> Locale: ...

stubs/sortedcontainers/sorteddict.pyi

@@ -2,6 +2,8 @@
 # https://github.com/grantjenks/python-sortedcontainers/blob/eea42df1f7bad2792e8da77335ff888f04b9e5ae/sortedcontainers/sorteddict.pyi
 # (from https://github.com/grantjenks/python-sortedcontainers/pull/107)
 
+from __future__ import annotations
+
 from typing import (
     Any,
     Callable,

stubs/sortedcontainers/sortedlist.pyi

@@ -2,6 +2,8 @@
 # https://github.com/grantjenks/python-sortedcontainers/blob/a419ffbd2b1c935b09f11f0971696e537fd0c510/sortedcontainers/sortedlist.pyi
 # (from https://github.com/grantjenks/python-sortedcontainers/pull/107)
 
+from __future__ import annotations
+
 from typing import (
     Any,
     Callable,

stubs/sortedcontainers/sortedset.pyi

@@ -2,6 +2,8 @@
 # https://github.com/grantjenks/python-sortedcontainers/blob/d0a225d7fd0fb4c54532b8798af3cbeebf97e2d5/sortedcontainers/sortedset.pyi
 # (from https://github.com/grantjenks/python-sortedcontainers/pull/107)
 
+from __future__ import annotations
+
 from typing import (
     AbstractSet,
     Any,

synapse/config/_base.pyi

+from __future__ import annotations
+
 import argparse
 from typing import (
     Any,