From e21db500a0a19a9ba4ce5ddc6a28c25d1857922f Mon Sep 17 00:00:00 2001
From: Matt Fisher <mfisher87@gmail.com>
Date: Mon, 28 Aug 2023 08:40:00 -0600
Subject: [PATCH 1/6] Switch from flake8 (and isort) to ruff

Ruff is fast, and this commit only aims to take advange of that, not to
add new rules.
---
 .flake8                           |  5 ---
 .pre-commit-config.yaml           | 19 +++++-------
 environments/dev-environment.yaml |  6 ----
 pyproject.toml                    | 51 +++++++++++++++++++++++++------
 requirements-dev.txt              |  7 -----
 5 files changed, 48 insertions(+), 40 deletions(-)
 delete mode 100644 .flake8

diff --git a/.flake8 b/.flake8
deleted file mode 100644
index b61e46d48..000000000
--- a/.flake8
+++ /dev/null
@@ -1,5 +0,0 @@
-[flake8]
-ignore = E203, E266, E501, W503, F403, F401
-max-line-length = 89
-max-complexity = 18
-select = B,C,E,F,W,T4,B9
\ No newline at end of file
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 8f6c693af..7d51e8ebe 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -8,9 +8,9 @@ repos:
 - repo: https://github.com/pre-commit/pre-commit-hooks
   rev: v4.4.0
   hooks:
-    - id: trailing-whitespace
-      exclude: "^.*\\.patch$"
-    - id: check-ast
+  - id: trailing-whitespace
+    exclude: "^.*\\.patch$"
+  - id: check-ast
 
 - repo: https://github.com/psf/black
   rev: 23.7.0
@@ -18,16 +18,11 @@ repos:
   - id: black
     language_version: python3
 
-- repo: https://github.com/pycqa/flake8
-  rev: 6.1.0
+- repo: https://github.com/astral-sh/ruff-pre-commit
+  rev: v0.0.286
   hooks:
-    - id: flake8
-
-- repo: https://github.com/pycqa/isort
-  rev: 5.12.0
-  hooks:
-  - id: isort
-    args: ["--profile", "black", "--filter-files"]
+  - id: ruff
+    args: ["--fix"]
 
 - repo: https://github.com/pre-commit/mirrors-mypy
   rev: v1.5.1
diff --git a/environments/dev-environment.yaml b/environments/dev-environment.yaml
index 14a05a878..bee5b5a24 100644
--- a/environments/dev-environment.yaml
+++ b/environments/dev-environment.yaml
@@ -8,19 +8,13 @@ dependencies:
 - check-manifest
 - doctr
 - filelock
-- flake8
-- flake8-builtins
-- flake8-comprehensions
-- flake8-mutable
 - python-build
 - freezegun
 - isort
 - mypy
 - pre-commit
-- pylint
 - pytest
 - pytest-cov
-- pytest-flake8
 - pytest-xdist
 - pytest-timeout
 - tomli
diff --git a/pyproject.toml b/pyproject.toml
index 390b7dd7c..7de4748f4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -108,16 +108,6 @@ exclude = [
     "tests",
 ]
 
-[tool.isort]
-atomic = true
-force_grid_wrap = 0
-include_trailing_comma = true
-lines_after_imports = 2
-lines_between_types = 1
-multi_line_output = 3
-use_parentheses = true
-known_first_party = "attr"
-
 [tool.pytest.ini_options]
 addopts = "-vrsx -n auto"
 flake8-max-line-length = 105
@@ -157,3 +147,44 @@ platforms = ["linux-64", "osx-64", "osx-arm64", "win-64", "osx-arm64", "linux-aa
 # This is necessary to pull in the lockfile/filelock dependency
 # since we don't handle the optional dependency.
 cachecontrol-with-filecache = ">=0.12.9"
+
+
+[tool.ruff]
+ignore = [
+    "E501",
+    "F401",
+    "F403",
+    # Disabled during migration to Ruff:
+    "A001",
+    "A002",
+    "A003",
+    "C401",
+    "C405",
+    "C408",
+    "C409",
+    "C413",
+    "C414",
+    "C416",
+    "RUF012",
+    "RUF015",
+]
+line-length = 89
+select = [
+    "A",  # flake8-builtins
+    # "B",  # flake8-bugbear
+    "C4",  # flake8-comprehensions
+    "C9",  # mccabe
+    "E",  # pycodestyle errors
+    "F",  # pyflakes
+    "I",  # isort
+    "RUF",  # ruff rules
+    "W",  # pycodestyle warnings
+]
+
+[tool.ruff.mccabe]
+max-complexity = 18
+
+[tool.ruff.isort]
+lines-after-imports = 2
+lines-between-types = 1
+known-first-party = ["attr"]
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 62bcf44c4..b4feceec3 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,19 +1,12 @@
 black
 check-manifest
 doctr
-flake8
-flake8-builtins
-flake8-comprehensions
-flake8-mutable
 build
 freezegun
-isort
 mypy
 pre_commit
-pylint
 pytest
 pytest-cov
-pytest-flake8
 pytest-xdist
 pytest-timeout
 tomli; python_version<"3.11"

From f015fdd3f82c821364d4eca27c94ff47ba5eb08a Mon Sep 17 00:00:00 2001
From: Matt Fisher <mfisher87@gmail.com>
Date: Sun, 27 Aug 2023 18:25:53 -0600
Subject: [PATCH 2/6] Autofix a manageable set of new rules

These all felt likely to be uncontroversial choices for letting Ruff
autofix some new rules.
---
 conda_lock/conda_lock.py               | 6 +++---
 conda_lock/conda_solver.py             | 2 +-
 conda_lock/lockfile/v2prelim/models.py | 4 +++-
 conda_lock/models/channel.py           | 2 +-
 conda_lock/src_parser/meta_yaml.py     | 4 ++--
 5 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/conda_lock/conda_lock.py b/conda_lock/conda_lock.py
index ff398783d..d8c4e44b7 100644
--- a/conda_lock/conda_lock.py
+++ b/conda_lock/conda_lock.py
@@ -241,7 +241,7 @@ def fn_to_dist_name(fn: str) -> str:
     return fn
 
 
-def make_lock_files(  # noqa: C901
+def make_lock_files(
     *,
     conda: PathLike,
     src_files: List[pathlib.Path],
@@ -943,10 +943,10 @@ def _render_lockfile_for_install(
     if platform not in lock_content.metadata.platforms:
         suggested_platforms_section = "platforms:\n- "
         suggested_platforms_section += "\n- ".join(
-            [platform] + lock_content.metadata.platforms
+            [platform, *lock_content.metadata.platforms]
         )
         suggested_platform_args = "--platform=" + " --platform=".join(
-            [platform] + lock_content.metadata.platforms
+            [platform, *lock_content.metadata.platforms]
         )
         raise PlatformValidationError(
             f"The lockfile {filename} does not contain a solution for the current "
diff --git a/conda_lock/conda_solver.py b/conda_lock/conda_solver.py
index eb9fb6ef6..9c414e640 100644
--- a/conda_lock/conda_solver.py
+++ b/conda_lock/conda_solver.py
@@ -476,7 +476,7 @@ def update_specs_for_arch(
             proc = subprocess.run(
                 [
                     str(arg)
-                    for arg in args + ["-p", prefix, "--json", "--dry-run", *to_update]
+                    for arg in [*args, "-p", prefix, "--json", "--dry-run", *to_update]
                 ],
                 env=conda_env_override(platform),
                 stdout=subprocess.PIPE,
diff --git a/conda_lock/lockfile/v2prelim/models.py b/conda_lock/lockfile/v2prelim/models.py
index 038a7e14e..2cc35c26a 100644
--- a/conda_lock/lockfile/v2prelim/models.py
+++ b/conda_lock/lockfile/v2prelim/models.py
@@ -7,10 +7,12 @@
     GitMeta,
     HashModel,
     InputMeta,
+    LockMeta,
+    MetadataOption,
+    TimeMeta,
 )
 from conda_lock.lockfile.v1.models import LockedDependency as LockedDependencyV1
 from conda_lock.lockfile.v1.models import Lockfile as LockfileV1
-from conda_lock.lockfile.v1.models import LockMeta, MetadataOption, TimeMeta
 from conda_lock.models import StrictModel
 
 
diff --git a/conda_lock/models/channel.py b/conda_lock/models/channel.py
index 5cb3b6143..60874f3f4 100644
--- a/conda_lock/models/channel.py
+++ b/conda_lock/models/channel.py
@@ -143,7 +143,7 @@ def _detect_used_env_var(
 
     if value.startswith("$"):
         return value.lstrip("$").strip("{}")
-    for suffix in preferred_env_var_suffix + [""]:
+    for suffix in [*preferred_env_var_suffix, ""]:
         candidates = {v: k for k, v in os.environ.items() if k.upper().endswith(suffix)}
         # try first with a simple match
         key = candidates.get(value)
diff --git a/conda_lock/src_parser/meta_yaml.py b/conda_lock/src_parser/meta_yaml.py
index 79470027a..5ebd8768f 100644
--- a/conda_lock/src_parser/meta_yaml.py
+++ b/conda_lock/src_parser/meta_yaml.py
@@ -47,7 +47,7 @@ def __init__(  # type: ignore
     __mod__ = __rmod__ = __pos__ = __neg__ = __call__ = \
     __getitem__ = __lt__ = __le__ = __gt__ = __ge__ = \
     __complex__ = __pow__ = __rpow__ = \
-        lambda self, *args, **kwargs: self._return_undefined(self._undefined_name)  # noqa: E122
+        lambda self, *args, **kwargs: self._return_undefined(self._undefined_name)
     # fmt: on
 
     # Accessing an attribute of an Undefined variable
@@ -60,7 +60,7 @@ def __getattr__(self, k: str) -> "UndefinedNeverFail":
 
     # Unlike the methods above, Python requires that these
     # few methods must always return the correct type
-    __str__ = __repr__ = lambda self: self._return_value(str())  # type: ignore  # noqa: E731
+    __str__ = __repr__ = lambda self: self._return_value(str())  # type: ignore
     __unicode__ = lambda self: self._return_value("")  # noqa: E731
     __int__ = lambda self: self._return_value(0)  # type: ignore  # noqa: E731
     __float__ = lambda self: self._return_value(0.0)  # type: ignore  # noqa: E731

From 3aca73e99e92e0cbd5d9784a69ca8e504821b378 Mon Sep 17 00:00:00 2001
From: Matt Fisher <mfisher87@gmail.com>
Date: Sun, 27 Aug 2023 18:43:31 -0600
Subject: [PATCH 3/6] Specify target version

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

diff --git a/pyproject.toml b/pyproject.toml
index 7de4748f4..cce0cc543 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -150,6 +150,7 @@ cachecontrol-with-filecache = ">=0.12.9"
 
 
 [tool.ruff]
+target-version = "py38"
 ignore = [
     "E501",
     "F401",

From dbd131ebae4dad837cef787c63da030f31e6b21a Mon Sep 17 00:00:00 2001
From: Matt Fisher <mfisher87@gmail.com>
Date: Sun, 27 Aug 2023 18:52:30 -0600
Subject: [PATCH 4/6] Enable and autofix B006

---
 conda_lock/conda_lock.py | 4 +++-
 pyproject.toml           | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/conda_lock/conda_lock.py b/conda_lock/conda_lock.py
index d8c4e44b7..0c96d4c84 100644
--- a/conda_lock/conda_lock.py
+++ b/conda_lock/conda_lock.py
@@ -768,7 +768,7 @@ def create_lockfile_from_spec(
     *,
     conda: PathLike,
     spec: LockSpecification,
-    platforms: List[str] = [],
+    platforms: Optional[List[str]] = None,
     lockfile_path: pathlib.Path,
     update_spec: Optional[UpdateSpecification] = None,
     metadata_choices: AbstractSet[MetadataOption] = frozenset(),
@@ -778,6 +778,8 @@ def create_lockfile_from_spec(
     """
     Solve or update specification
     """
+    if platforms is None:
+        platforms = []
     assert spec.virtual_package_repo is not None
     virtual_package_channel = spec.virtual_package_repo.channel
 
diff --git a/pyproject.toml b/pyproject.toml
index cce0cc543..b6523232f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -173,6 +173,7 @@ line-length = 89
 select = [
     "A",  # flake8-builtins
     # "B",  # flake8-bugbear
+    "B006",  # Do not use mutable data structures for argument defaults
     "C4",  # flake8-comprehensions
     "C9",  # mccabe
     "E",  # pycodestyle errors

From 95f64eafa6724ad5745ac1a7ab0e4f148b8d01ad Mon Sep 17 00:00:00 2001
From: Matt Fisher <mfisher87@gmail.com>
Date: Mon, 28 Aug 2023 19:17:02 -0600
Subject: [PATCH 5/6] Restore flake8 and isort in a way that's compatible with
 ruff

I'm sure there are better ways to do this than `# isort: skip_file` and
flake8 `per-file-ignores`, but this is what I had time for today :)
---
 .flake8                                | 10 ++++++++++
 .pre-commit-config.yaml                | 12 ++++++++++++
 conda_lock/lockfile/v2prelim/models.py |  5 ++---
 pyproject.toml                         | 14 ++++++++++++++
 4 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 .flake8

diff --git a/.flake8 b/.flake8
new file mode 100644
index 000000000..684ff8df7
--- /dev/null
+++ b/.flake8
@@ -0,0 +1,10 @@
+[flake8]
+# NOTE: Can ruff replace flake8? See `tool.isort`, these two configs should be
+# kept in sync until we pick one.
+ignore = E203, E266, E501, W503, F403, F401
+per-file-ignores =
+  conda_lock/src_parser/meta_yaml.py:E122
+
+max-line-length = 89
+max-complexity = 19
+select = B,C,E,F,W,T4,B9
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 7d51e8ebe..8c45525aa 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -24,6 +24,18 @@ repos:
   - id: ruff
     args: ["--fix"]
 
+# Ruff should catch (and mostly fix) everything that flake8 and isort do; if
+# either of these checks fails, can Ruff's config be updated to catch the same?
+- repo: https://github.com/pycqa/flake8
+  rev: 6.1.0
+  hooks:
+  - id: flake8
+- repo: https://github.com/pycqa/isort
+  rev: 5.12.0
+  hooks:
+  - id: isort
+    args: ["--profile", "black", "--filter-files"]
+
 - repo: https://github.com/pre-commit/mirrors-mypy
   rev: v1.5.1
   hooks:
diff --git a/conda_lock/lockfile/v2prelim/models.py b/conda_lock/lockfile/v2prelim/models.py
index 2cc35c26a..fd36dbade 100644
--- a/conda_lock/lockfile/v2prelim/models.py
+++ b/conda_lock/lockfile/v2prelim/models.py
@@ -1,3 +1,4 @@
+# isort: skip_file
 from collections import defaultdict
 from typing import ClassVar, Dict, List, Optional
 
@@ -7,12 +8,10 @@
     GitMeta,
     HashModel,
     InputMeta,
-    LockMeta,
-    MetadataOption,
-    TimeMeta,
 )
 from conda_lock.lockfile.v1.models import LockedDependency as LockedDependencyV1
 from conda_lock.lockfile.v1.models import Lockfile as LockfileV1
+from conda_lock.lockfile.v1.models import LockMeta, MetadataOption, TimeMeta
 from conda_lock.models import StrictModel
 
 
diff --git a/pyproject.toml b/pyproject.toml
index b6523232f..9fb2c0b64 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -108,6 +108,18 @@ exclude = [
     "tests",
 ]
 
+[tool.isort]
+# NOTE: Can ruff replace isort? See `tool.ruff.isort`, these two configs should
+# be kept in sync until we pick one.
+atomic = true
+force_grid_wrap = 0
+include_trailing_comma = true
+lines_after_imports = 2
+lines_between_types = 1
+multi_line_output = 3
+use_parentheses = true
+known_first_party = "attr"
+
 [tool.pytest.ini_options]
 addopts = "-vrsx -n auto"
 flake8-max-line-length = 105
@@ -187,6 +199,8 @@ select = [
 max-complexity = 18
 
 [tool.ruff.isort]
+# NOTE: Can ruff replace isort? See `tool.isort`, these two configs should be
+# kept in sync until we pick one.
 lines-after-imports = 2
 lines-between-types = 1
 known-first-party = ["attr"]

From 52cb31b69a87ca879c5c3e8228e2125c16932bef Mon Sep 17 00:00:00 2001
From: Matt Fisher <mfisher87@gmail.com>
Date: Tue, 29 Aug 2023 18:22:48 -0600
Subject: [PATCH 6/6] Add context to isort skip comment

---
 conda_lock/lockfile/v2prelim/models.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/conda_lock/lockfile/v2prelim/models.py b/conda_lock/lockfile/v2prelim/models.py
index fd36dbade..71ad4352f 100644
--- a/conda_lock/lockfile/v2prelim/models.py
+++ b/conda_lock/lockfile/v2prelim/models.py
@@ -1,4 +1,6 @@
 # isort: skip_file
+# TODO: Remove the isort skip comment above if/when isort is no longer used. This skip
+# exists because isort and ruff disagree about how to sort the imports in this file.
 from collections import defaultdict
 from typing import ClassVar, Dict, List, Optional