Start setting up tox

It is not completely working yet.

Author: EliahKagan

Diff for: .gitignore

@@ -24,4 +24,3 @@ nbproject
 .pytest_cache/
 monkeytype.sqlite3
 output.txt
-tox.ini

Diff for: requirements-dev.txt

@@ -7,6 +7,3 @@ flake8-type-checking;python_version>="3.8"      # checks for TYPE_CHECKING only
 
 pytest-icdiff
 # pytest-profiling
-
-
-tox

Diff for: tox.ini

@@ -0,0 +1,24 @@
+[tox]
+requires = tox>=4
+env_list = py{37,38,39,310,311,312}, lint, mypy, black
+
+[testenv]
+description = Run unit tests
+package = wheel
+extras = test
+commands = pytest --color=yes {posargs}
+
+[testenv:lint]
+description = Lint via pre-commit
+basepython = py39
+commands = pre-commit run --all-files
+
+[testenv:mypy]
+description = Typecheck with mypy
+basepython = py39
+commands = mypy -p git
+
+[testenv:black]
+description = Check style with black
+basepython = py39
+commands = black --check --diff git