From 0ee7349e6b755e5d7b74dd441de9ccebf2c086f8 Mon Sep 17 00:00:00 2001
From: dosisod <39638017+dosisod@users.noreply.github.com>
Date: Sat, 3 Jun 2023 16:51:53 -0700
Subject: [PATCH 1/6] Switch from `flake8` to `ruff`:

To quote Ruff's README: "An extremely fast Python linter, written in Rust".

In my testing Ruff takes 200ms to lint the entire codebase whereas flake8
takes about 5.5 seconds (27x slower). Running `pre-commit run -a` only takes
about 2.3 seconds now, which should make local dev work a bit faster (assuming
you run linters regularly).

Ruff includes a lot of rules out of the box, including all the (important)
rules from `flake8`, `flake8-bugbear`, `flake8-noqa`, and many more. Having
all these built-in rules makes it much easier to incrementally improve the
codebase without having to install tons of flake8 plugins.

I made sure that the configs matched as close as I could get them. Some minor
rules like line indentation and such aren't in Ruff since they are always just
disabled. Ruff also ignores everything in the `.gitignore` file, so that cleans
up the exclude section.

Lastly, the `test-data` section seemed to have its own `.flake8` config file,
but it was disabled in the `setup.cfg` file. I migrated the config over, but
it doesn't really matter because it is being ignored anyways. Is this
intentional?
---
 .github/workflows/test.yml  |  2 +-
 .gitignore                  |  1 -
 .pre-commit-config.yaml     | 13 +++--------
 CONTRIBUTING.md             |  2 +-
 mypy/server/objgraph.py     |  4 ++--
 mypyc/irbuild/specialize.py |  2 +-
 pyproject.toml              | 38 ++++++++++++++++++++++++++++++++
 setup.cfg                   | 43 -------------------------------------
 test-data/.flake8           | 22 -------------------
 test-data/unit/README.md    |  2 +-
 test-requirements.txt       |  4 +---
 11 files changed, 48 insertions(+), 85 deletions(-)
 delete mode 100644 test-data/.flake8

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 81587f3ca747..6fc8fb11c6f4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -96,7 +96,7 @@ jobs:
           # We also run these checks with pre-commit in CI,
           # but it's useful to run them with tox too,
           # to ensure the tox env works as expected
-        - name: Formatting with Black + isort and code style with flake8
+        - name: Formatting with Black + isort and code style with ruff
           python: '3.10'
           arch: x64
           os: ubuntu-latest
diff --git a/.gitignore b/.gitignore
index c6761f0ed736..6c35e3d89342 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,5 @@ test_capi
 *.o
 *.a
 test_capi
-/.mypyc-flake8-cache.json
 /mypyc/lib-rt/build/
 /mypyc/lib-rt/*.so
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 92d827fba006..4e4ab681cc98 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -13,14 +13,7 @@ repos:
     rev: 5.12.0  # must match test-requirements.txt
     hooks:
       - id: isort
-  - repo: https://github.com/pycqa/flake8
-    rev: 6.0.0  # must match test-requirements.txt
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.0.270  # must match test-requirements.txt
     hooks:
-      - id: flake8
-        additional_dependencies:
-          - flake8-bugbear==23.3.23  # must match test-requirements.txt
-          - flake8-noqa==1.3.1       # must match test-requirements.txt
-
-ci:
-  # We run flake8 as part of our GitHub Actions suite in CI
-  skip: [flake8]
+      - id: ruff
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d169d7f3159e..99ba2f8c9a76 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -89,7 +89,7 @@ pytest -n0 -k 'test_name'
 pytest mypy/test/testcheck.py::TypeCheckSuite::check-dataclasses.test
 
 # Run the linter
-flake8
+ruff .
 
 # Run formatters
 black . && isort .
diff --git a/mypy/server/objgraph.py b/mypy/server/objgraph.py
index 89a086b8a0ab..37d0f4d2ca1a 100644
--- a/mypy/server/objgraph.py
+++ b/mypy/server/objgraph.py
@@ -46,7 +46,7 @@ def get_edge_candidates(o: object) -> Iterator[tuple[object, object]]:
             try:
                 if attr not in ATTR_BLACKLIST and hasattr(o, attr) and not isproperty(o, attr):
                     e = getattr(o, attr)
-                    if not type(e) in ATOMIC_TYPE_BLACKLIST:
+                    if type(e) not in ATOMIC_TYPE_BLACKLIST:
                         yield attr, e
             except AssertionError:
                 pass
@@ -70,7 +70,7 @@ def get_edges(o: object) -> Iterator[tuple[object, object]]:
                 if se is not o and se is not type(o) and hasattr(s, "__self__"):
                     yield s.__self__, se
         else:
-            if not type(e) in TYPE_BLACKLIST:
+            if type(e) not in TYPE_BLACKLIST:
                 yield s, e
 
 
diff --git a/mypyc/irbuild/specialize.py b/mypyc/irbuild/specialize.py
index ff9df0cd597b..14a6f8e92df2 100644
--- a/mypyc/irbuild/specialize.py
+++ b/mypyc/irbuild/specialize.py
@@ -446,7 +446,7 @@ def translate_sum_call(builder: IRBuilder, expr: CallExpr, callee: RefExpr) -> V
     # handle 'start' argument, if given
     if len(expr.args) == 2:
         # ensure call to sum() was properly constructed
-        if not expr.arg_kinds[1] in (ARG_POS, ARG_NAMED):
+        if expr.arg_kinds[1] not in (ARG_POS, ARG_NAMED):
             return None
         start_expr = expr.args[1]
     else:
diff --git a/pyproject.toml b/pyproject.toml
index 3d100dff5101..f2b9c9621d13 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,3 +39,41 @@ skip_glob = [
     "mypyc/test-data/*",
     "test-data/*",
 ]
+
+[tool.ruff]
+line-length = 99
+
+# Things to ignore:
+#   B006: use of mutable defaults in function signatures
+#   B007: Loop control variable not used within the loop body.
+#   B011: Don't use assert False
+#   B023: Function definition does not bind loop variable
+#   E203: conflicts with black
+#   E402: module level import not at top of file
+#   E501: conflicts with black
+#   E731: Do not assign a `lambda` expression, use a `def`
+#   E741: Ambiguous variable name
+extend-ignore = ["B006", "B007", "B011", "B023", "E203", "E402", "E501", "E731", "E741"]
+
+extend-exclude = [
+  "@*",
+  # Sphinx configuration is irrelevant
+  "docs/source/conf.py",
+  "mypyc/doc/conf.py",
+  # tests have more relaxed styling requirements
+  # fixtures have their own .pyi-specific configuration
+  "test-data/*",
+  "mypyc/test-data/*",
+  # typeshed has its own .pyi-specific configuration
+  "mypy/typeshed/*",
+]
+
+[tool.ruff.per-file-ignores]
+
+# Some PEP8 deviations are considered irrelevant to stub files:
+# (error counts as of 2016-12-19)
+#  1487 F401 imported but unused
+#  1248 E701 multiple statements on one line (colon)
+#   427 F811 redefinition
+
+"test-data/*" = ["F401", "F811", "E701"]
diff --git a/setup.cfg b/setup.cfg
index 511f794474e7..04d75ac8d19f 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,46 +1,3 @@
-[flake8]
-max-line-length = 99
-noqa-require-code = True
-# typeshed and unit test fixtures have .pyi-specific flake8 configuration
-exclude =
-  # from .gitignore: directories, and file patterns that intersect with *.py
-  build,
-  bin,
-  lib,
-  include,
-  @*,
-  env,
-  docs/build,
-  out,
-  .venv,
-  .mypy_cache,
-  .git,
-  .cache,
-  # Sphinx configuration is irrelevant
-  docs/source/conf.py,
-  mypyc/doc/conf.py,
-  # tests have more relaxed styling requirements
-  # fixtures have their own .pyi-specific configuration
-  test-data/*,
-  mypyc/test-data/*,
-  # typeshed has its own .pyi-specific configuration
-  mypy/typeshed/*,
-  .tox
-  .eggs
-  .Python
-
-# Things to ignore:
-#   E203: conflicts with black
-#   E501: conflicts with black
-#   W601: has_key() deprecated (false positives)
-#   E402: module level import not at top of file
-#   B006: use of mutable defaults in function signatures
-#   B007: Loop control variable not used within the loop body.
-#   B011: Don't use assert False
-#   B023: Function definition does not bind loop variable
-#   E741: Ambiguous variable name
-extend-ignore = E203,E501,W601,E402,B006,B007,B011,B023,E741
-
 [coverage:run]
 branch = true
 source = mypy
diff --git a/test-data/.flake8 b/test-data/.flake8
deleted file mode 100644
index df2f9caf8c94..000000000000
--- a/test-data/.flake8
+++ /dev/null
@@ -1,22 +0,0 @@
-# Some PEP8 deviations are considered irrelevant to stub files:
-# (error counts as of 2016-12-19)
-# 17381 E704 multiple statements on one line (def)
-# 11840 E301 expected 1 blank line
-#  7467 E302 expected 2 blank lines
-#  1772 E501 line too long
-#  1487 F401 imported but unused
-#  1248 E701 multiple statements on one line (colon)
-#   427 F811 redefinition
-#   356 E305 expected 2 blank lines
-
-# Nice-to-haves ignored for now
-#   152 E128 continuation line under-indented for visual indent
-#    43 E127 continuation line over-indented for visual indent
-
-[flake8]
-ignore = F401, F811, E127, E128, E301, E302, E305, E501, E701, E704, B303
-# We are checking with Python 3 but many of the stubs are Python 2 stubs.
-# A nice future improvement would be to provide separate .flake8
-# configurations for Python 2 and Python 3 files.
-builtins = StandardError,apply,basestring,buffer,cmp,coerce,execfile,file,intern,long,raw_input,reduce,reload,unichr,unicode,xrange
-exclude = .venv*,@*
diff --git a/test-data/unit/README.md b/test-data/unit/README.md
index 97680c949bef..f2c727b43543 100644
--- a/test-data/unit/README.md
+++ b/test-data/unit/README.md
@@ -159,7 +159,7 @@ To run mypy on itself:
 
 To run the linter:
 
-    flake8
+    ruff .
 
 You can also run all of the above tests using `runtests.py` (this includes
 type checking mypy and linting):
diff --git a/test-requirements.txt b/test-requirements.txt
index 42c8a08a2b5d..b13166b22d12 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -3,9 +3,6 @@
 attrs>=18.0
 black==23.3.0  # must match version in .pre-commit-config.yaml
 filelock>=3.3.0
-flake8==6.0.0; python_version >= "3.8"           # must match version in .pre-commit-config.yaml
-flake8-bugbear==23.3.23; python_version >= "3.8" # must match version in .pre-commit-config.yaml
-flake8-noqa==1.3.1; python_version >= "3.8"      # must match version in .pre-commit-config.yaml
 isort[colors]==5.12.0; python_version >= "3.8"   # must match version in .pre-commit-config.yaml
 lxml>=4.9.1; (python_version<'3.11' or sys_platform!='win32') and python_version<'3.12'
 pre-commit
@@ -17,6 +14,7 @@ pytest-xdist>=1.34.0
 pytest-forked>=1.3.0,<2.0.0
 pytest-cov>=2.10.0
 py>=1.5.2
+ruff==0.0.270  # must match version in .pre-commit-config.yaml
 setuptools>=65.5.1
 six
 tomli>=1.1.0

From df7ed7af5d872460c490a576b35ff71195595c3a Mon Sep 17 00:00:00 2001
From: dosisod <39638017+dosisod@users.noreply.github.com>
Date: Sat, 3 Jun 2023 17:45:21 -0700
Subject: [PATCH 2/6] Make comments inline [skip ci]

---
 pyproject.toml | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index f2b9c9621d13..d41cd625614d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -43,17 +43,17 @@ skip_glob = [
 [tool.ruff]
 line-length = 99
 
-# Things to ignore:
-#   B006: use of mutable defaults in function signatures
-#   B007: Loop control variable not used within the loop body.
-#   B011: Don't use assert False
-#   B023: Function definition does not bind loop variable
-#   E203: conflicts with black
-#   E402: module level import not at top of file
-#   E501: conflicts with black
-#   E731: Do not assign a `lambda` expression, use a `def`
-#   E741: Ambiguous variable name
-extend-ignore = ["B006", "B007", "B011", "B023", "E203", "E402", "E501", "E731", "E741"]
+extend-ignore = [
+  "B006",  # use of mutable defaults in function signatures
+  "B007",  # Loop control variable not used within the loop body.
+  "B011",  # Don't use assert False
+  "B023",  # Function definition does not bind loop variable
+  "E203",  # conflicts with black
+  "E402",  # module level import not at top of file
+  "E501",  # conflicts with black
+  "E731",  # Do not assign a `lambda` expression, use a `def`
+  "E741",  # Ambiguous variable name
+]
 
 extend-exclude = [
   "@*",
@@ -70,10 +70,8 @@ extend-exclude = [
 
 [tool.ruff.per-file-ignores]
 
-# Some PEP8 deviations are considered irrelevant to stub files:
-# (error counts as of 2016-12-19)
-#  1487 F401 imported but unused
-#  1248 E701 multiple statements on one line (colon)
-#   427 F811 redefinition
-
-"test-data/*" = ["F401", "F811", "E701"]
+"test-data/*" = [
+  "F401",  # imported but unused
+  "F811",  # redefinition
+  "E701",  # multiple statements on one line (colon)
+]

From 26633c5b9ca14e31768776ed3f5857b490102504 Mon Sep 17 00:00:00 2001
From: dosisod <39638017+dosisod@users.noreply.github.com>
Date: Fri, 16 Jun 2023 23:08:36 -0700
Subject: [PATCH 3/6] Add `target-version` flag to Ruff

---
 pyproject.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pyproject.toml b/pyproject.toml
index d41cd625614d..8980b2e4e708 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,6 +42,7 @@ skip_glob = [
 
 [tool.ruff]
 line-length = 99
+target-version = "py37"
 
 extend-ignore = [
   "B006",  # use of mutable defaults in function signatures

From 76259836d8149ca08d65ca4a015fc9b0ec38790e Mon Sep 17 00:00:00 2001
From: dosisod <39638017+dosisod@users.noreply.github.com>
Date: Sun, 18 Jun 2023 21:46:30 -0700
Subject: [PATCH 4/6] Add review suggestions

---
 .pre-commit-config.yaml | 2 +-
 mypy/build.py           | 4 ++--
 mypy/plugins/common.py  | 4 +---
 mypy/typeanal.py        | 2 +-
 mypy/types.py           | 2 +-
 pyproject.toml          | 9 ++++++++-
 test-requirements.txt   | 2 +-
 7 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 4e4ab681cc98..cbb3672bd986 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -14,6 +14,6 @@ repos:
     hooks:
       - id: isort
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.0.270  # must match test-requirements.txt
+    rev: v0.0.272  # must match test-requirements.txt
     hooks:
       - id: ruff
diff --git a/mypy/build.py b/mypy/build.py
index 7913eae9c6ed..413e94b5fb8e 100644
--- a/mypy/build.py
+++ b/mypy/build.py
@@ -3077,7 +3077,7 @@ def load_graph(
             manager.errors.report(
                 -1,
                 -1,
-                "See https://mypy.readthedocs.io/en/stable/running_mypy.html#mapping-file-paths-to-modules "  # noqa: E501
+                "See https://mypy.readthedocs.io/en/stable/running_mypy.html#mapping-file-paths-to-modules "
                 "for more info",
                 severity="note",
             )
@@ -3165,7 +3165,7 @@ def load_graph(
                             manager.errors.report(
                                 -1,
                                 0,
-                                "See https://mypy.readthedocs.io/en/stable/running_mypy.html#mapping-file-paths-to-modules "  # noqa: E501
+                                "See https://mypy.readthedocs.io/en/stable/running_mypy.html#mapping-file-paths-to-modules "
                                 "for more info",
                                 severity="note",
                             )
diff --git a/mypy/plugins/common.py b/mypy/plugins/common.py
index f803387cde8b..65d967577bea 100644
--- a/mypy/plugins/common.py
+++ b/mypy/plugins/common.py
@@ -28,9 +28,7 @@
     require_bool_literal_argument,
     set_callable_name,
 )
-from mypy.typeops import (  # noqa: F401  # Part of public API
-    try_getting_str_literals as try_getting_str_literals,
-)
+from mypy.typeops import try_getting_str_literals as try_getting_str_literals
 from mypy.types import (
     AnyType,
     CallableType,
diff --git a/mypy/typeanal.py b/mypy/typeanal.py
index d1e6e315b9e3..f2e17b2beedc 100644
--- a/mypy/typeanal.py
+++ b/mypy/typeanal.py
@@ -1256,7 +1256,7 @@ def analyze_callable_type(self, t: UnboundType) -> Type:
                         code=codes.VALID_TYPE,
                     )
                     self.note(
-                        "See https://mypy.readthedocs.io/en/stable/kinds_of_types.html#callable-types-and-lambdas",  # noqa: E501
+                        "See https://mypy.readthedocs.io/en/stable/kinds_of_types.html#callable-types-and-lambdas",
                         t,
                     )
                     return AnyType(TypeOfAny.from_error)
diff --git a/mypy/types.py b/mypy/types.py
index 5fbdd385826c..d0c7caf457ab 100644
--- a/mypy/types.py
+++ b/mypy/types.py
@@ -2957,7 +2957,7 @@ def get_proper_types(
 # to make it easier to gradually get modules working with mypyc.
 # Import them here, after the types are defined.
 # This is intended as a re-export also.
-from mypy.type_visitor import (  # noqa: F811,F401
+from mypy.type_visitor import (  # noqa: F811
     ALL_STRATEGY as ALL_STRATEGY,
     ANY_STRATEGY as ANY_STRATEGY,
     BoolTypeQuery as BoolTypeQuery,
diff --git a/pyproject.toml b/pyproject.toml
index 8980b2e4e708..b4b118ca9a24 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,7 +44,14 @@ skip_glob = [
 line-length = 99
 target-version = "py37"
 
-extend-ignore = [
+select = [
+  "E",       # pycoderstyle (error)
+  "F",       # pyflakes
+  "B",       # flake8-bugbear
+  "RUF100",  # flake8-noqa
+]
+
+ignore = [
   "B006",  # use of mutable defaults in function signatures
   "B007",  # Loop control variable not used within the loop body.
   "B011",  # Don't use assert False
diff --git a/test-requirements.txt b/test-requirements.txt
index b13166b22d12..51cd62d4064c 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -14,7 +14,7 @@ pytest-xdist>=1.34.0
 pytest-forked>=1.3.0,<2.0.0
 pytest-cov>=2.10.0
 py>=1.5.2
-ruff==0.0.270  # must match version in .pre-commit-config.yaml
+ruff==0.0.272  # must match version in .pre-commit-config.yaml
 setuptools>=65.5.1
 six
 tomli>=1.1.0

From 580c503a647b7ba61cec1e9c3db4528c1b299807 Mon Sep 17 00:00:00 2001
From: dosisod <39638017+dosisod@users.noreply.github.com>
Date: Sun, 18 Jun 2023 21:55:39 -0700
Subject: [PATCH 5/6] Remove `per-file-ignores` setting

---
 pyproject.toml | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index b4b118ca9a24..2baabe007f19 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -75,11 +75,3 @@ extend-exclude = [
   # typeshed has its own .pyi-specific configuration
   "mypy/typeshed/*",
 ]
-
-[tool.ruff.per-file-ignores]
-
-"test-data/*" = [
-  "F401",  # imported but unused
-  "F811",  # redefinition
-  "E701",  # multiple statements on one line (colon)
-]

From 925089fdbedac0cf1a64bd850e351315cd3c82ae Mon Sep 17 00:00:00 2001
From: Logan Hunt <39638017+dosisod@users.noreply.github.com>
Date: Mon, 19 Jun 2023 21:35:30 -0700
Subject: [PATCH 6/6] Update pyproject.toml

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
---
 pyproject.toml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index 2baabe007f19..b46bbd670e60 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,7 +48,8 @@ select = [
   "E",       # pycoderstyle (error)
   "F",       # pyflakes
   "B",       # flake8-bugbear
-  "RUF100",  # flake8-noqa
+  "RUF100",  # Unused noqa comments
+  "PGH004"  # blanket noqa comments
 ]
 
 ignore = [