Bug 1811850 - [lint] Replace pylint linter with ruff, r=linter-reviewers,marco

This is enabling the PLE and PLC rules across a much larger swatch of the code
base. The PLR and PLW are additionally enabled at the warning level (introduces
~2500 new warnings).

To avoid extraneous changes in people's patches, rules at the warning level are
excluded from --fix.

Differential Revision: https://phabricator.services.mozilla.com/D172358

docs/code-quality/index.rst

@@ -100,11 +100,6 @@ In this document, we try to list these all tools.
      - `bug 1555560 <https://bugzilla.mozilla.org/show_bug.cgi?id=1555560>`__
      - :ref:`black`
      - https://black.readthedocs.io/en/stable
-   * - pylint
-     -
-     - `bug 1623024 <https://bugzilla.mozilla.org/show_bug.cgi?id=1623024>`__
-     - :ref:`pylint`
-     - https://www.pylint.org/
 
 .. list-table:: Rust
    :widths: 20 20 20 20 20

docs/code-quality/lint/linters/pylint.rst

@@ -1,33 +0,0 @@
-pylint
-======
-
-`pylint <https://www.pylint.org/>`__ is a popular linter for python. It is now the default python
-linter in VS Code.
-
-Please note that we also have :ref:`Flake8` available as a linter.
-
-Run Locally
------------
-
-The mozlint integration of pylint can be run using mach:
-
-.. parsed-literal::
-
-    $ mach lint --linter pylint <file paths>
-
-
-
-Configuration
--------------
-
-To enable pylint on new directory, add the path to the include
-section in the `pylint.yml <https://searchfox.org/mozilla-central/source/tools/lint/pylint.yml>`_ file.
-
-We enabled the same Pylint rules as `VS Code <https://code.visualstudio.com/docs/python/linting#_pylint>`_.
-See in `pylint.py <https://searchfox.org/mozilla-central/source/tools/lint/python/pylint.py>`_ for the full list
-
-Sources
--------
-
-* `Configuration (YAML) <https://searchfox.org/mozilla-central/source/tools/lint/pylint.yml>`_
-* `Source <https://searchfox.org/mozilla-central/source/tools/lint/python/pylint.py>`_

pyproject.toml

@@ -5,6 +5,7 @@ select = [
   "E", "W",    # pycodestyle
   "F",         # pyflakes
   "I",         # isort
+  "PL",        # pylint
 ]
 ignore = [
   # These should be triaged and either fixed or moved to the list below.
@@ -100,6 +101,7 @@ exclude = [
 
 [tool.ruff.per-file-ignores]
 # These paths are intentionally excluded.
+"dom/bindings/Configuration.py" = ["PLC3002"]
 "ipc/ipdl/*" = ["F403", "F405"]
 "layout/tools/reftest/selftest/conftest.py" = ["F811"]
 # cpp_eclipse has a lot of multi-line embedded XML which exceeds line length
@@ -108,6 +110,7 @@ exclude = [
 "testing/marionette/**/__init__.py" = ["F401"]
 "testing/mochitest/tests/python/conftest.py" = ["F811"]
 "testing/mozbase/manifestparser/tests/test_filters.py" = ["E731"]
+"testing/mozbase/mozinfo/mozinfo/mozinfo.py" = ["PLE0605"]
 "testing/mozbase/mozlog/tests/test_formatters.py" = ["E501"]
 "testing/mozharness/configs/*" = ["E501"]
 "**/*.configure" = ["F821"]

taskcluster/ci/source-test/mozlint.yml

@@ -274,19 +274,6 @@ py-ruff:
             - 'tools/lint/python/ruff.py'
             - 'tools/lint/python/ruff_requirements.txt'
 
-py-pylint:
-    description: pylint run over the gecko codebase
-    treeherder:
-        symbol: py(pylint)
-    run:
-        mach: lint -v -l pylint -f treeherder -f json:/builds/worker/mozlint.json *
-    when:
-        files-changed:
-            - '**/*.py'
-            - 'tools/lint/pylint.yml'
-            # moz.configure files are also Python files
-            # However, pylint has some hard time dealing with it
-
 test-manifest:
     description: lint test manifests
     treeherder:

tools/lint/file-whitespace.yml

@@ -3,7 +3,6 @@ file-whitespace:
     description: File content sanity check
     include:
         - .
-        - tools/lint/python/pylint_requirements.txt
         - tools/lint/python/black_requirements.txt
         - tools/lint/python/ruff_requirements.txt
         - tools/lint/rst/requirements.txt

tools/lint/pylint.yml

@@ -1,24 +0,0 @@
----
-pylint:
-    description: A second Python linter
-    include:
-        - configure.py
-        - client.py
-        - security/
-        - accessible/
-        - docs/
-        - dom/base/
-        - dom/websocket/
-        - mozglue/
-        - toolkit/components/telemetry/
-    exclude:
-        - dom/bindings/Codegen.py
-        - security/manager/ssl/tests/unit/test_content_signing/pysign.py
-        - security/ct/tests/gtest/createSTHTestData.py
-    extensions: ['py']
-    support-files:
-        - '**/.pylint'
-        - 'tools/lint/python/pylint*'
-    type: external
-    payload: python.pylint:lint
-    setup: python.pylint:setup

tools/lint/python/pylint.py

@@ -1,133 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-import json
-import os
-import signal
-import subprocess
-
-from mach.site import InstallPipRequirementsException
-from mozlint import result
-from mozlint.pathutils import expand_exclusions
-from mozprocess import ProcessHandler
-
-here = os.path.abspath(os.path.dirname(__file__))
-PYLINT_REQUIREMENTS_PATH = os.path.join(here, "pylint_requirements.txt")
-
-PYLINT_NOT_FOUND = """
-Could not find pylint! Install pylint and try again.
-
-    $ pip install -U --require-hashes -r {}
-""".strip().format(
-    PYLINT_REQUIREMENTS_PATH
-)
-
-
-PYLINT_INSTALL_ERROR = """
-Unable to install correct version of pylint
-Try to install it manually with:
-    $ pip install -U --require-hashes -r {}
-""".strip().format(
-    PYLINT_REQUIREMENTS_PATH
-)
-
-
-class PylintProcess(ProcessHandler):
-    def __init__(self, config, *args, **kwargs):
-        self.config = config
-        kwargs["stream"] = False
-        kwargs["universal_newlines"] = True
-        ProcessHandler.__init__(self, *args, **kwargs)
-
-    def run(self, *args, **kwargs):
-        orig = signal.signal(signal.SIGINT, signal.SIG_IGN)
-        ProcessHandler.run(self, *args, **kwargs)
-        signal.signal(signal.SIGINT, orig)
-
-
-def setup(root, **lintargs):
-    virtualenv_manager = lintargs["virtualenv_manager"]
-    try:
-        virtualenv_manager.install_pip_requirements(
-            PYLINT_REQUIREMENTS_PATH,
-            quiet=True,
-        )
-    except (subprocess.CalledProcessError, InstallPipRequirementsException):
-        print(PYLINT_INSTALL_ERROR)
-        return 1
-
-
-def get_pylint_binary():
-    return "pylint"
-
-
-def run_process(config, cmd):
-    proc = PylintProcess(config, cmd)
-    proc.run()
-    try:
-        proc.wait()
-    except KeyboardInterrupt:
-        proc.kill()
-
-    return proc.output
-
-
-def parse_issues(log, config, issues_json, path):
-    results = []
-
-    try:
-        issues = json.loads(issues_json)
-    except json.decoder.JSONDecodeError:
-        log.debug("Could not parse the output:")
-        log.debug("pylint output: {}".format(issues_json))
-        return []
-
-    for issue in issues:
-        res = {
-            "path": issue["path"],
-            "level": issue["type"],
-            "lineno": issue["line"],
-            "column": issue["column"],
-            "message": issue["message"],
-            "rule": issue["message-id"],
-        }
-        results.append(result.from_config(config, **res))
-    return results
-
-
-def get_pylint_version(binary):
-    return subprocess.check_output(
-        [binary, "--version"],
-        universal_newlines=True,
-        stderr=subprocess.STDOUT,
-    )
-
-
-def lint(paths, config, **lintargs):
-    log = lintargs["log"]
-
-    binary = get_pylint_binary()
-
-    log = lintargs["log"]
-    paths = list(expand_exclusions(paths, config, lintargs["root"]))
-
-    cmd_args = [binary]
-    results = []
-
-    # list from https://code.visualstudio.com/docs/python/linting#_pylint
-    # And ignore a bit more elements
-    cmd_args += [
-        "-fjson",
-        "--disable=all",
-        "--enable=F,E,unreachable,duplicate-key,unnecessary-semicolon,global-variable-not-assigned,unused-variable,binary-op-exception,bad-format-string,anomalous-backslash-in-string,bad-open-mode,no-else-return",  # NOQA: E501
-        "--disable=import-error,no-member",
-    ]
-
-    base_command = cmd_args + paths
-    log.debug("Command: {}".format(" ".join(cmd_args)))
-    log.debug("pylint version: {}".format(get_pylint_version(binary)))
-    output = " ".join(run_process(config, base_command))
-    results = parse_issues(log, config, str(output), [])
-
-    return results

tools/lint/python/pylint_requirements.in

@@ -1,5 +0,0 @@
-pylint==2.15.8
-dill==0.3.4
-tomli==1.2.2
-typing-extensions==3.10.0.2
-tomlkit==0.10.1

tools/lint/python/pylint_requirements.txt

@@ -1,136 +0,0 @@
-#
-# This file is autogenerated by pip-compile with python 3.10
-# To update, run:
-#
-#    pip-compile --generate-hashes tools/lint/python/pylint_requirements.in
-#
-astroid==2.12.13 \
-    --hash=sha256:10e0ad5f7b79c435179d0d0f0df69998c4eef4597534aae44910db060baeb907 \
-    --hash=sha256:1493fe8bd3dfd73dc35bd53c9d5b6e49ead98497c47b2307662556a5692d29d7
-    # via pylint
-dill==0.3.4 \
-    --hash=sha256:7e40e4a70304fd9ceab3535d36e58791d9c4a776b38ec7f7ec9afc8d3dca4d4f \
-    --hash=sha256:9f9734205146b2b353ab3fec9af0070237b6ddae78452af83d2fca84d739e675
-    # via
-    #   -r tools/lint/python/pylint_requirements.in
-    #   pylint
-isort==5.11.2 \
-    --hash=sha256:dd8bbc5c0990f2a095d754e50360915f73b4c26fc82733eb5bfc6b48396af4d2 \
-    --hash=sha256:e486966fba83f25b8045f8dd7455b0a0d1e4de481e1d7ce4669902d9fb85e622
-    # via pylint
-lazy-object-proxy==1.8.0 \
-    --hash=sha256:0c1c7c0433154bb7c54185714c6929acc0ba04ee1b167314a779b9025517eada \
-    --hash=sha256:14010b49a2f56ec4943b6cf925f597b534ee2fe1f0738c84b3bce0c1a11ff10d \
-    --hash=sha256:4e2d9f764f1befd8bdc97673261b8bb888764dfdbd7a4d8f55e4fbcabb8c3fb7 \
-    --hash=sha256:4fd031589121ad46e293629b39604031d354043bb5cdf83da4e93c2d7f3389fe \
-    --hash=sha256:5b51d6f3bfeb289dfd4e95de2ecd464cd51982fe6f00e2be1d0bf94864d58acd \
-    --hash=sha256:6850e4aeca6d0df35bb06e05c8b934ff7c533734eb51d0ceb2d63696f1e6030c \
-    --hash=sha256:6f593f26c470a379cf7f5bc6db6b5f1722353e7bf937b8d0d0b3fba911998858 \
-    --hash=sha256:71d9ae8a82203511a6f60ca5a1b9f8ad201cac0fc75038b2dc5fa519589c9288 \
-    --hash=sha256:7e1561626c49cb394268edd00501b289053a652ed762c58e1081224c8d881cec \
-    --hash=sha256:8f6ce2118a90efa7f62dd38c7dbfffd42f468b180287b748626293bf12ed468f \
-    --hash=sha256:ae032743794fba4d171b5b67310d69176287b5bf82a21f588282406a79498891 \
-    --hash=sha256:afcaa24e48bb23b3be31e329deb3f1858f1f1df86aea3d70cb5c8578bfe5261c \
-    --hash=sha256:b70d6e7a332eb0217e7872a73926ad4fdc14f846e85ad6749ad111084e76df25 \
-    --hash=sha256:c219a00245af0f6fa4e95901ed28044544f50152840c5b6a3e7b2568db34d156 \
-    --hash=sha256:ce58b2b3734c73e68f0e30e4e725264d4d6be95818ec0a0be4bb6bf9a7e79aa8 \
-    --hash=sha256:d176f392dbbdaacccf15919c77f526edf11a34aece58b55ab58539807b85436f \
-    --hash=sha256:e20bfa6db17a39c706d24f82df8352488d2943a3b7ce7d4c22579cb89ca8896e \
-    --hash=sha256:eac3a9a5ef13b332c059772fd40b4b1c3d45a3a2b05e33a361dee48e54a4dad0 \
-    --hash=sha256:eb329f8d8145379bf5dbe722182410fe8863d186e51bf034d2075eb8d85ee25b
-    # via astroid
-mccabe==0.7.0 \
-    --hash=sha256:348e0240c33b60bbdf4e523192ef919f28cb2c3d7d5c7794f74009290f236325 \
-    --hash=sha256:6c2d30ab6be0e4a46919781807b4f0d834ebdd6c6e3dca0bda5a15f863427b6e
-    # via pylint
-platformdirs==2.6.0 \
-    --hash=sha256:1a89a12377800c81983db6be069ec068eee989748799b946cce2a6e80dcc54ca \
-    --hash=sha256:b46ffafa316e6b83b47489d240ce17173f123a9b9c83282141c3daf26ad9ac2e
-    # via pylint
-pylint==2.15.8 \
-    --hash=sha256:ea82cd6a1e11062dc86d555d07c021b0fb65afe39becbe6fe692efd6c4a67443 \
-    --hash=sha256:ec4a87c33da054ab86a6c79afa6771dc8765cb5631620053e727fcf3ef8cbed7
-    # via -r tools/lint/python/pylint_requirements.in
-tomli==1.2.2 \
-    --hash=sha256:c6ce0015eb38820eaf32b5db832dbc26deb3dd427bd5f6556cf0acac2c214fee \
-    --hash=sha256:f04066f68f5554911363063a30b108d2b5a5b1a010aa8b6132af78489fe3aade
-    # via
-    #   -r tools/lint/python/pylint_requirements.in
-    #   pylint
-tomlkit==0.10.1 \
-    --hash=sha256:3c517894eadef53e9072d343d37e4427b8f0b6200a70b7c9a19b2ebd1f53b951 \
-    --hash=sha256:3eba517439dcb2f84cf39f4f85fd2c3398309823a3c75ac3e73003638daf7915
-    # via
-    #   -r tools/lint/python/pylint_requirements.in
-    #   pylint
-typing-extensions==3.10.0.2 \
-    --hash=sha256:49f75d16ff11f1cd258e1b988ccff82a3ca5570217d7ad8c5f48205dd99a677e \
-    --hash=sha256:d8226d10bc02a29bcc81df19a26e56a9647f8b0a6d4a83924139f4a8b01f17b7 \
-    --hash=sha256:f1d25edafde516b146ecd0613dabcc61409817af4766fbbcfb8d1ad4ec441a34
-    # via -r tools/lint/python/pylint_requirements.in
-wrapt==1.14.1 \
-    --hash=sha256:00b6d4ea20a906c0ca56d84f93065b398ab74b927a7a3dbd470f6fc503f95dc3 \
-    --hash=sha256:01c205616a89d09827986bc4e859bcabd64f5a0662a7fe95e0d359424e0e071b \
-    --hash=sha256:02b41b633c6261feff8ddd8d11c711df6842aba629fdd3da10249a53211a72c4 \
-    --hash=sha256:07f7a7d0f388028b2df1d916e94bbb40624c59b48ecc6cbc232546706fac74c2 \
-    --hash=sha256:11871514607b15cfeb87c547a49bca19fde402f32e2b1c24a632506c0a756656 \
-    --hash=sha256:1b376b3f4896e7930f1f772ac4b064ac12598d1c38d04907e696cc4d794b43d3 \
-    --hash=sha256:21ac0156c4b089b330b7666db40feee30a5d52634cc4560e1905d6529a3897ff \
-    --hash=sha256:257fd78c513e0fb5cdbe058c27a0624c9884e735bbd131935fd49e9fe719d310 \
-    --hash=sha256:2b39d38039a1fdad98c87279b48bc5dce2c0ca0d73483b12cb72aa9609278e8a \
-    --hash=sha256:2cf71233a0ed05ccdabe209c606fe0bac7379fdcf687f39b944420d2a09fdb57 \
-    --hash=sha256:2fe803deacd09a233e4762a1adcea5db5d31e6be577a43352936179d14d90069 \
-    --hash=sha256:3232822c7d98d23895ccc443bbdf57c7412c5a65996c30442ebe6ed3df335383 \
-    --hash=sha256:34aa51c45f28ba7f12accd624225e2b1e5a3a45206aa191f6f9aac931d9d56fe \
-    --hash=sha256:36f582d0c6bc99d5f39cd3ac2a9062e57f3cf606ade29a0a0d6b323462f4dd87 \
-    --hash=sha256:380a85cf89e0e69b7cfbe2ea9f765f004ff419f34194018a6827ac0e3edfed4d \
-    --hash=sha256:40e7bc81c9e2b2734ea4bc1aceb8a8f0ceaac7c5299bc5d69e37c44d9081d43b \
-    --hash=sha256:43ca3bbbe97af00f49efb06e352eae40434ca9d915906f77def219b88e85d907 \
-    --hash=sha256:4fcc4649dc762cddacd193e6b55bc02edca674067f5f98166d7713b193932b7f \
-    --hash=sha256:5a0f54ce2c092aaf439813735584b9537cad479575a09892b8352fea5e988dc0 \
-    --hash=sha256:5a9a0d155deafd9448baff28c08e150d9b24ff010e899311ddd63c45c2445e28 \
-    --hash=sha256:5b02d65b9ccf0ef6c34cba6cf5bf2aab1bb2f49c6090bafeecc9cd81ad4ea1c1 \
-    --hash=sha256:60db23fa423575eeb65ea430cee741acb7c26a1365d103f7b0f6ec412b893853 \
-    --hash=sha256:642c2e7a804fcf18c222e1060df25fc210b9c58db7c91416fb055897fc27e8cc \
-    --hash=sha256:6a9a25751acb379b466ff6be78a315e2b439d4c94c1e99cb7266d40a537995d3 \
-    --hash=sha256:6b1a564e6cb69922c7fe3a678b9f9a3c54e72b469875aa8018f18b4d1dd1adf3 \
-    --hash=sha256:6d323e1554b3d22cfc03cd3243b5bb815a51f5249fdcbb86fda4bf62bab9e164 \
-    --hash=sha256:6e743de5e9c3d1b7185870f480587b75b1cb604832e380d64f9504a0535912d1 \
-    --hash=sha256:709fe01086a55cf79d20f741f39325018f4df051ef39fe921b1ebe780a66184c \
-    --hash=sha256:7b7c050ae976e286906dd3f26009e117eb000fb2cf3533398c5ad9ccc86867b1 \
-    --hash=sha256:7d2872609603cb35ca513d7404a94d6d608fc13211563571117046c9d2bcc3d7 \
-    --hash=sha256:7ef58fb89674095bfc57c4069e95d7a31cfdc0939e2a579882ac7d55aadfd2a1 \
-    --hash=sha256:80bb5c256f1415f747011dc3604b59bc1f91c6e7150bd7db03b19170ee06b320 \
-    --hash=sha256:81b19725065dcb43df02b37e03278c011a09e49757287dca60c5aecdd5a0b8ed \
-    --hash=sha256:833b58d5d0b7e5b9832869f039203389ac7cbf01765639c7309fd50ef619e0b1 \
-    --hash=sha256:88bd7b6bd70a5b6803c1abf6bca012f7ed963e58c68d76ee20b9d751c74a3248 \
-    --hash=sha256:8ad85f7f4e20964db4daadcab70b47ab05c7c1cf2a7c1e51087bfaa83831854c \
-    --hash=sha256:8c0ce1e99116d5ab21355d8ebe53d9460366704ea38ae4d9f6933188f327b456 \
-    --hash=sha256:8d649d616e5c6a678b26d15ece345354f7c2286acd6db868e65fcc5ff7c24a77 \
-    --hash=sha256:903500616422a40a98a5a3c4ff4ed9d0066f3b4c951fa286018ecdf0750194ef \
-    --hash=sha256:9736af4641846491aedb3c3f56b9bc5568d92b0692303b5a305301a95dfd38b1 \
-    --hash=sha256:988635d122aaf2bdcef9e795435662bcd65b02f4f4c1ae37fbee7401c440b3a7 \
-    --hash=sha256:9cca3c2cdadb362116235fdbd411735de4328c61425b0aa9f872fd76d02c4e86 \
-    --hash=sha256:9e0fd32e0148dd5dea6af5fee42beb949098564cc23211a88d799e434255a1f4 \
-    --hash=sha256:9f3e6f9e05148ff90002b884fbc2a86bd303ae847e472f44ecc06c2cd2fcdb2d \
-    --hash=sha256:a85d2b46be66a71bedde836d9e41859879cc54a2a04fad1191eb50c2066f6e9d \
-    --hash=sha256:a9a52172be0b5aae932bef82a79ec0a0ce87288c7d132946d645eba03f0ad8a8 \
-    --hash=sha256:aa31fdcc33fef9eb2552cbcbfee7773d5a6792c137b359e82879c101e98584c5 \
-    --hash=sha256:b014c23646a467558be7da3d6b9fa409b2c567d2110599b7cf9a0c5992b3b471 \
-    --hash=sha256:b21bb4c09ffabfa0e85e3a6b623e19b80e7acd709b9f91452b8297ace2a8ab00 \
-    --hash=sha256:b5901a312f4d14c59918c221323068fad0540e34324925c8475263841dbdfe68 \
-    --hash=sha256:b9b7a708dd92306328117d8c4b62e2194d00c365f18eff11a9b53c6f923b01e3 \
-    --hash=sha256:d1967f46ea8f2db647c786e78d8cc7e4313dbd1b0aca360592d8027b8508e24d \
-    --hash=sha256:d52a25136894c63de15a35bc0bdc5adb4b0e173b9c0d07a2be9d3ca64a332735 \
-    --hash=sha256:d77c85fedff92cf788face9bfa3ebaa364448ebb1d765302e9af11bf449ca36d \
-    --hash=sha256:d79d7d5dc8a32b7093e81e97dad755127ff77bcc899e845f41bf71747af0c569 \
-    --hash=sha256:dbcda74c67263139358f4d188ae5faae95c30929281bc6866d00573783c422b7 \
-    --hash=sha256:ddaea91abf8b0d13443f6dac52e89051a5063c7d014710dcb4d4abb2ff811a59 \
-    --hash=sha256:dee0ce50c6a2dd9056c20db781e9c1cfd33e77d2d569f5d1d9321c641bb903d5 \
-    --hash=sha256:dee60e1de1898bde3b238f18340eec6148986da0455d8ba7848d50470a7a32fb \
-    --hash=sha256:e2f83e18fe2f4c9e7db597e988f72712c0c3676d337d8b101f6758107c42425b \
-    --hash=sha256:e3fb1677c720409d5f671e39bac6c9e0e422584e5f518bfd50aa4cbbea02433f \
-    --hash=sha256:ee2b1b1769f6707a8a445162ea16dddf74285c3964f605877a20e38545c3c462 \
-    --hash=sha256:ee6acae74a2b91865910eef5e7de37dc6895ad96fa23603d1d27ea69df545015 \
-    --hash=sha256:ef3f72c9666bba2bab70d2a8b79f2c6d2c1a42a7f7e2b0ec83bb2f9e383950af
-    # via astroid

tools/lint/python/ruff.py

@@ -141,10 +141,15 @@ def lint(paths, config, log, **lintargs):
 
     process_kwargs = {"processStderrLine": lambda line: log.debug(line)}
 
+    warning_rules = set(config.get("warning-rules", []))
     if lintargs.get("fix"):
         # Do a first pass with --fix-only as the json format doesn't return the
         # number of fixed issues.
-        output = run_process(config, args + ["--fix-only"], **process_kwargs)
+        fix_args = args + ["--fix-only"]
+
+        # Don't fix warnings to limit unrelated changes sneaking into patches.
+        fix_args.append(f"--extend-ignore={','.join(warning_rules)}")
+        output = run_process(config, fix_args, **process_kwargs)
         matches = re.match(r"Fixed (\d+) errors?.", output)
         if matches:
             fixed = int(matches[1])
@@ -159,7 +164,6 @@ def lint(paths, config, log, **lintargs):
         log.error(f"could not parse output: {output}")
         return []
 
-    warning_rules = set(config.get("warning-rules", []))
     for issue in issues:
         res = {
             "path": issue["filename"],
@@ -168,8 +172,11 @@ def lint(paths, config, log, **lintargs):
             "lineoffset": issue["end_location"]["row"] - issue["location"]["row"],
             "message": issue["message"],
             "rule": issue["code"],
-            "level": "warning" if issue["code"] in warning_rules else "error",
+            "level": "error",
         }
+        if any(issue["code"].startswith(w) for w in warning_rules):
+            res["level"] = "warning"
+
         if issue["fix"]:
             res["hint"] = issue["fix"]["message"]
 

tools/lint/ruff.yml

@@ -11,7 +11,7 @@ ruff:
         - "**/pyproject.toml"
         - "tools/lint/python/ruff.py"
     # Rules that should result in warnings rather than errors.
-    warning-rules: []
+    warning-rules: [PLR, PLW]
     type: external
     payload: python.ruff:lint
     setup: python.ruff:setup

tools/lint/test/files/pylint/bad.py

@@ -1,5 +0,0 @@
-def foo():
-    useless_var = 1
-    useless_var = true
-    return "true"
-    print("unreachable")

tools/lint/test/files/pylint/good.py

@@ -1,3 +0,0 @@
-def foo():
-    a = 1 + 1
-    return a

tools/lint/test/python.ini

@@ -20,8 +20,6 @@ skip-if = os == "win"
 [test_perfdocs_generation.py]
 [test_updatebot.py]
 [test_perfdocs_helpers.py]
-[test_pylint.py]
-requirements = tools/lint/python/pylint_requirements.txt
 [test_rst.py]
 requirements = tools/lint/rst/requirements.txt
 [test_ruff.py]

tools/lint/test/test_pylint.py

@@ -1,24 +0,0 @@
-import mozunit
-
-LINTER = "pylint"
-
-
-def test_lint_single_file(lint, paths):
-    results = lint(paths("bad.py"))
-    assert len(results) == 3
-    assert results[1].rule == "E0602"
-    assert results[2].rule == "W0101"
-    assert results[2].lineno == 5
-
-    # run lint again to make sure the previous results aren't counted twice
-    results = lint(paths("bad.py"))
-    assert len(results) == 3
-
-
-def test_lint_single_file_good(lint, paths):
-    results = lint(paths("good.py"))
-    assert len(results) == 0
-
-
-if __name__ == "__main__":
-    mozunit.main()