Add support for 'tox'

Adding 'tox' [^1] makes it possible to test xocto against multiple
versions of Python.

[^1]: https://tox.wiki/

docs/xocto/development.md

@@ -55,6 +55,17 @@ their own pull requests.
 When you are ready, commit both `pyproject.toml` and
 `requirements.txt`.
 
+## tox
+
+Run [tox](https://tox.wiki/) to test the package on supported versions
+of Python.
+
+Each versions of Python listed in `tox.ini` must be present on your
+system. On Linux it is probably easiest to build each version from
+source, using `make altinstall`.
+If you use Mac you can install each version using homebrew e.g.,
+`brew install [email protected]`.
+
 ## Publishing
 
 ### Version number

pyproject.toml

@@ -56,6 +56,8 @@ dev = [
   "pytest",
   "ruff",
   "time-machine",
+  "tox",
+  "tox-uv",
   "twine",
   "types-openpyxl",
   "types-python-dateutil",

requirements.txt

@@ -25,6 +25,8 @@ botocore==1.29.53
     #   s3transfer
 bytecode==0.15.1
     # via ddtrace
+cachetools==5.4.0
+    # via tox
 cattrs==23.2.3
     # via ddtrace
 certifi==2024.7.4
@@ -35,12 +37,16 @@ cffi==1.17.0
     #   pact-python
 cfgv==3.4.0
     # via pre-commit
+chardet==5.2.0
+    # via tox
 charset-normalizer==3.3.2
     # via requests
 click==8.1.7
     # via
     #   pact-python
     #   uvicorn
+colorama==0.4.6
+    # via tox
 cryptography==43.0.0
     # via moto
 ddsketch==3.0.1
@@ -70,7 +76,9 @@ exceptiongroup==1.2.2
 fastapi==0.112.0
     # via pact-python
 filelock==3.15.4
-    # via virtualenv
+    # via
+    #   tox
+    #   virtualenv
 h11==0.14.0
     # via uvicorn
 hypothesis==6.62.1
@@ -138,17 +146,25 @@ openpyxl==3.1.5
 opentelemetry-api==1.16.0
     # via ddtrace
 packaging==24.1
-    # via pytest
+    # via
+    #   pyproject-api
+    #   pytest
+    #   tox
+    #   tox-uv
 pact-python==2.2.1
     # via xocto (pyproject.toml)
 pandas==2.0.3
     # via xocto (pyproject.toml)
 pkginfo==1.11.1
     # via twine
 platformdirs==4.2.2
-    # via virtualenv
+    # via
+    #   tox
+    #   virtualenv
 pluggy==1.5.0
-    # via pytest
+    # via
+    #   pytest
+    #   tox
 pre-commit==3.8.0
     # via xocto (pyproject.toml)
 protobuf==5.27.3
@@ -171,6 +187,8 @@ pygments==2.18.0
     # via
     #   readme-renderer
     #   rich
+pyproject-api==1.7.1
+    # via tox
 pytest==8.0.2
     # via
     #   xocto (pyproject.toml)
@@ -242,7 +260,15 @@ time-machine==2.14.1
 tomli==2.0.1
     # via
     #   mypy
+    #   pyproject-api
     #   pytest
+    #   tox
+tox==4.17.1
+    # via
+    #   xocto (pyproject.toml)
+    #   tox-uv
+tox-uv==1.11.1
+    # via xocto (pyproject.toml)
 twine==4.0.2
     # via xocto (pyproject.toml)
 types-openpyxl==3.0.4.5
@@ -269,6 +295,7 @@ typing-extensions==4.12.2
     #   pydantic
     #   pydantic-core
     #   starlette
+    #   tox-uv
     #   uvicorn
 tzdata==2024.1
     # via pandas
@@ -278,10 +305,14 @@ urllib3==1.26.19
     #   requests
     #   responses
     #   twine
+uv==0.2.34
+    # via tox-uv
 uvicorn==0.30.5
     # via pact-python
 virtualenv==20.26.3
-    # via pre-commit
+    # via
+    #   pre-commit
+    #   tox
 werkzeug==3.0.3
     # via moto
 wheel==0.38.4

tox.ini

@@ -0,0 +1,15 @@
+[tox]
+min_version = 4.0
+envlist = py39
+
+[testenv]
+# Install wheels instead of source distributions for faster execution.
+package = wheel
+# Share the build environment between tox environments.
+wheel_build_env = .pkg
+
+# Run type checking because 'typing' and related packages vary among versions of Python
+allowlist_externals = make
+commands =
+    uv pip sync requirements.txt
+    make test mypy