Add types, remove dead code, and beef up lints

pyproject.toml

@@ -1,7 +1,3 @@
-[build-system]
-requires = ["pdm-backend"]
-build-backend = "pdm.backend"
-
 [project]
 name = "stack-pr"
 authors = [
@@ -20,20 +16,40 @@ classifiers = [
     "Intended Audience :: Developers",
     "Topic :: Software Development :: Version Control :: Git",
     "License :: OSI Approved :: Apache Software License",
+    "Operating System :: OS Independent",
+    "Environment :: Console",
+    "Topic :: Utilities",
     "Programming Language :: Python",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
 ]
 # Version is dynamically set by pdm by the SCM version
 dynamic = ["version"]
-dependencies = []
+dependencies = ["typing_extensions; python_version<\"3.13\""]
+
+[project.optional-dependencies]
+dev = [
+    "pytest",
+    "pytest-mock",
+    "mypy",
+    "ruff",
+]
 
 [project.urls]
-Homepage = "https://github.com/modularml/stack-pr"
-Repository = "https://github.com/modularml/stack-pr"
-"Bug Tracker" = "https://github.com/modularml/stack-pr/issues"
+Homepage = "https://github.com/modular/stack-pr"
+Repository = "https://github.com/modular/stack-pr"
+"Bug Tracker" = "https://github.com/modular/stack-pr/issues"
 
 [project.scripts]
 stack-pr = "stack_pr.cli:main"
 
+[build-system]
+requires = ["pdm-backend"]
+build-backend = "pdm.backend"
+
 [tool.pdm]
 distribution = true
 
@@ -52,4 +68,134 @@ pdm = ">=2.17.1,<2.18"
 [tool.pixi.tasks]
 
 [tool.pixi.dependencies]
-python = ">=3.8"
+python = "3.9.*"
+
+[tool.ruff]
+
+# Same as Black.
+line-length = 88
+
+# Assume Python 3.9
+target-version = "py39"
+
+[tool.ruff.lint]
+# Enable pycodestyle (`E`), Pyflakes (`F`), and isort (`I`) codes
+select = [
+    "E",   # pycodestyle errors
+    "F",   # pyflakes
+    "I",   # isort
+    "B",   # flake8-bugbear
+    "C4",  # flake8-comprehensions
+    "UP",  # pyupgrade
+    "N",   # pep8-naming
+    "SIM", # flake8-simplify
+    "RUF", # ruff-specific rules
+    "W",   # pycodestyle warnings
+    "YTT", # flake8-2020
+    "ANN", # flake8-annotations
+    "S",   # flake8-bandit
+    "BLE", # flake8-blind-except
+    "FBT", # flake8-boolean-trap
+    "A",   # flake8-builtins
+    "C",   # flake8-comprehensions
+    "DTZ", # flake8-datetimez
+    "T10", # flake8-debugger
+    "ISC", # flake8-implicit-str-concat
+    "G",   # flake8-logging-format
+    "INP", # flake8-no-pep420
+    "PIE", # flake8-pie
+    "T20", # flake8-print
+    "PT",  # flake8-pytest-style
+    "Q",   # flake8-quotes
+    "RSE", # flake8-raise
+    "RET", # flake8-return
+    "SLF", # flake8-self
+    "TID", # flake8-tidy-imports
+    "ARG", # flake8-unused-arguments
+    "PTH", # flake8-use-pathlib
+    "ERA", # eradicate
+    "PD",  # pandas-vet
+    "PGH", # pygrep-hooks
+    "PL",  # pylint
+    "TRY", # tryceratops
+    "FA100", #future-rewritable-type-annotation
+    "PYI036", # bad-exit-annotation
+    # "COM812", # trailing-comma (this one makes ruff formater mad)
+]
+
+# Ignore specific rules
+ignore = [
+    # This is just too complex to do anything about when invoking gh suprocess.
+    "S603",  # subprocess call with untrusted input
+
+    # We use some of the strings for output in the CLI and want specific formatting.
+    "TRY003", # Avoid specifying long messages outside exception class
+
+    # We forward kwargs a lot and ruff doesn't like it. (more than 5)
+    "PLR0913", # Too many arguments
+
+    # FIXME: We use print statements in the CLI instead of stderr/stdout (this may change)
+    "T201", # allow print statements
+
+    # FIXME: Some of our strings are long for CLI output. We should refactor them.
+    "E501", # Line too long
+]
+
+# Borrowing a rustism and allow unused variables when underscore-prefixed.
+dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
+
+[tool.ruff.lint.isort]
+known-first-party = ["stack_pr"]
+
+[tool.ruff.lint.mccabe]
+# Unlike Flake8, default to a complexity level of 16.
+max-complexity = 16
+
+[tool.ruff.lint.per-file-ignores]
+# Ignore unused imports in __init__.py files
+"__init__.py" = ["F401"]
+
+[tool.ruff.lint.pydocstyle]
+convention = "google"
+
+[tool.ruff.lint.pycodestyle]
+max-doc-length = 88
+
+[tool.ruff.lint.flake8-quotes]
+docstring-quotes = "double"
+inline-quotes = "double"
+multiline-quotes = "double"
+
+[tool.ruff.lint.extend-per-file-ignores]
+# Allow certain useful patterns in tests
+"tests/**/*.py" = [
+    "S101", # allow assert statements within if statements
+    "ARG", # allow unused arguments
+    "FBT", # allow boolean traps
+    "ANN401", # allow Any in tests
+    "T201", # allow print statements in tests
+    "PLR2004", # allow magic value comparisons in tests
+]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
+testpaths = ["tests"]
+python_files = ["test_*.py"]
+addopts = "-v"
+
+[tool.mypy]
+# Let's be strict.
+python_version = "3.9"
+warn_return_any = true
+warn_unused_configs = true
+disallow_untyped_defs = true
+disallow_incomplete_defs = true
+check_untyped_defs = true
+disallow_untyped_decorators = true
+no_implicit_optional = true
+warn_redundant_casts = true
+warn_unused_ignores = true
+warn_no_return = true
+warn_unreachable = true
+strict_optional = true

src/stack_pr/__main__.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from stack_pr.cli import main
 
 if __name__ == "__main__":