fix: the Python matrix and classifiers cover the whole supported range (#25)

The unit-test matrix was [min, "3.12", "3.13"]: a render with 3.12 as
its minimum tested 3.12 twice, one with 3.14 tested two versions below
its own floor, and nothing ran on 3.14. The classifiers named only the
minimum, and coverage was uploaded from 3.12 alone, so a render with a
higher minimum uploaded none.

Both lists now run from python_min_version to python_max_version, a
hidden copier.yml value (3.14) raised in one place. Coverage goes up
from the newest version. python_min_version is validated: a 3.x from
3.10 to python_max_version.

Author: AlexeyShalaev

README.md

@@ -24,7 +24,7 @@ Copier will prompt for:
 | `author_name` | Author full name | `Alex Shalaev` |
 | `author_email` | Author email | `you@example.com` |
 | `github_org` | GitHub org or username | `bedrock-python` |
-| `python_min_version` | Minimum Python version | `3.11` |
+| `python_min_version` | Minimum Python version, 3.10 to 3.14. The unit-test matrix and the classifiers run from it to the newest version (`python_max_version` in `copier.yml`) | `3.11` |
 | `initial_version` | Initial version | `0.0.0` |
 
 ## After generation

copier.yml

@@ -29,10 +29,23 @@ github_org:
   help: "GitHub organization or username"
   default: "bedrock-python"
 
+# The newest Python a render declares and runs its unit tests on. Not asked:
+# raise it here once the libraries move to a new release.
+python_max_version:
+  type: str
+  default: "3.14"
+  when: false
+
 python_min_version:
   type: str
-  help: "Minimum Python version"
+  help: "Minimum Python version (3.10 to {{ python_max_version }})"
   default: "3.11"
+  validator: >-
+    {%- set minor = python_min_version.split(".")[-1] -%}
+    {%- if not python_min_version.startswith("3.") or not minor.isdigit()
+        or minor | int < 10 or minor | int > python_max_version.split(".")[-1] | int -%}
+    Use a 3.x version from 3.10 to {{ python_max_version }}
+    {%- endif -%}
 
 initial_version:
   type: str

template/.github/workflows/ci.yml.jinja

@@ -25,7 +25,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["{{ python_min_version }}", "3.12", "3.13"]
+        python-version: [{% for minor in range(python_min_version.split(".")[1] | int, python_max_version.split(".")[1] | int + 1) %}"3.{{ minor }}"{{ ", " if not loop.last }}{% endfor %}]
     steps:
       - uses: actions/checkout@v7
       - uses: astral-sh/setup-uv@v7
@@ -34,7 +34,7 @@ jobs:
       - run: uv sync --group dev --all-extras
       - run: uv run pytest -m unit --cov={{ package_name }} --cov-report=xml --cov-fail-under=90
       - uses: codecov/codecov-action@v6
-        if: matrix.python-version == '3.12'
+        if: matrix.python-version == '{{ python_max_version }}'
         with:
           token: ${% raw %}{{ secrets.CODECOV_TOKEN }}{% endraw %}
           files: coverage.xml

template/pyproject.toml.jinja

@@ -12,7 +12,9 @@ classifiers = [
     "Intended Audience :: Developers",
     "License :: OSI Approved :: Apache Software License",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: {{ python_min_version }}",
+{%- for minor in range(python_min_version.split(".")[1] | int, python_max_version.split(".")[1] | int + 1) %}
+    "Programming Language :: Python :: 3.{{ minor }}",
+{%- endfor %}
     "Topic :: Software Development :: Libraries :: Python Modules",
     "Typing :: Typed",
 ]