Add pre-commit config with ruff and pre-commit-hooks

Based on pytest-dev conventions (pytest-cov).

Hooks:
- ruff-check with --fix for linting (E, F, I, W, UP)
- ruff-format for formatting
- trailing-whitespace, end-of-file-fixer, check-yaml

tests/fixtures/ excluded from ruff entirely (intentional
undefined names, deprecated methods, etc).

Author: graingert

.pre-commit-config.yaml

@@ -0,0 +1,13 @@
+repos:
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.15.9
+    hooks:
+      - id: ruff-check
+        args: [--fix]
+      - id: ruff-format
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v6.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml

pyproject.toml

@@ -51,3 +51,15 @@ push-changes = false
 tag-format = "v{version}"
 tag-message = "unittest2pytest {version}"
 tag-signing = true
+
+[tool.ruff]
+target-version = "py39"
+extend-exclude = ["tests/fixtures"]
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "W", "UP"]
+ignore = ["E501", "E701", "E741", "UP031"]
+
+[tool.ruff.lint.per-file-ignores]
+"unittest2pytest/fixes/fix_remove_class.py" = ["W291"]
+"unittest2pytest/fixes/fix_self_assert.py" = ["F841"]