Add rules-based tax-unit construction engine + PyPI release machinery

.github/bump_version.py

@@ -0,0 +1,77 @@
+"""Infer semver bump from towncrier fragment types and update version."""
+
+import re
+import sys
+from pathlib import Path
+
+
+def get_current_version(pyproject_path: Path) -> str:
+    text = pyproject_path.read_text()
+    match = re.search(r'^version\s*=\s*"(\d+\.\d+\.\d+)"', text, re.MULTILINE)
+    if not match:
+        print(
+            "Could not find version in pyproject.toml",
+            file=sys.stderr,
+        )
+        sys.exit(1)
+    return match.group(1)
+
+
+def infer_bump(changelog_dir: Path) -> str:
+    fragments = [
+        f for f in changelog_dir.iterdir() if f.is_file() and f.name != ".gitkeep"
+    ]
+    if not fragments:
+        print("No changelog fragments found", file=sys.stderr)
+        sys.exit(1)
+
+    categories = {f.suffix.lstrip(".") for f in fragments}
+    for f in fragments:
+        parts = f.stem.split(".")
+        if len(parts) >= 2:
+            categories.add(parts[-1])
+
+    if "breaking" in categories:
+        return "major"
+    if "added" in categories or "removed" in categories:
+        return "minor"
+    return "patch"
+
+
+def bump_version(version: str, bump: str) -> str:
+    major, minor, patch = (int(x) for x in version.split("."))
+    if bump == "major":
+        return f"{major + 1}.0.0"
+    elif bump == "minor":
+        return f"{major}.{minor + 1}.0"
+    else:
+        return f"{major}.{minor}.{patch + 1}"
+
+
+def update_file(path: Path, old_version: str, new_version: str):
+    text = path.read_text()
+    updated = text.replace(
+        f'version = "{old_version}"',
+        f'version = "{new_version}"',
+    )
+    if updated != text:
+        path.write_text(updated)
+        print(f"  Updated {path}")
+
+
+def main():
+    root = Path(__file__).resolve().parent.parent
+    pyproject = root / "pyproject.toml"
+    changelog_dir = root / "changelog.d"
+
+    current = get_current_version(pyproject)
+    bump = infer_bump(changelog_dir)
+    new = bump_version(current, bump)
+
+    print(f"Version: {current} -> {new} ({bump})")
+
+    update_file(pyproject, current, new)
+
+
+if __name__ == "__main__":
+    main()

.github/fetch_version.py

@@ -0,0 +1,10 @@
+"""Print the package version from pyproject.toml (used to tag releases)."""
+
+import re
+from pathlib import Path
+
+text = (Path(__file__).resolve().parent.parent / "pyproject.toml").read_text()
+match = re.search(r'^version\s*=\s*"(.+?)"', text, re.MULTILINE)
+if match is None:
+    raise SystemExit("Could not find version in pyproject.toml")
+print(match.group(1))

.github/publish-git-tag.sh

@@ -0,0 +1,4 @@
+#! /usr/bin/env bash
+
+git tag `python .github/fetch_version.py`  # create a new tag
+git push --tags || true  # update the repository version

.github/workflows/changelog_entry.yaml

@@ -0,0 +1,21 @@
+name: Changelog
+
+on:
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  check-changelog:
+    name: Check changelog fragment
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - name: Check for changelog fragment
+        run: |
+          FRAGMENTS=$(find changelog.d -type f ! -name '.gitkeep' | wc -l)
+          if [ "$FRAGMENTS" -eq 0 ]; then
+            echo "::error::No changelog fragment found in changelog.d/"
+            echo "Add one with: echo 'Description.' > changelog.d/\$(git branch --show-current).<type>.md"
+            echo "Types: added, changed, fixed, removed, breaking"
+            exit 1
+          fi

.github/workflows/main.yml

@@ -0,0 +1,30 @@
+name: CI
+on:
+  push:
+    branches: [ main ]
+
+jobs:
+  Test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.13"]
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v6
+      - name: Install uv
+        uses: astral-sh/setup-uv@v8.1.0
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v6
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: uv pip install -e ".[dev]" --system
+      - name: Run tests with coverage
+        run: make test
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v6
+        with:
+          files: ./coverage.xml
+          fail_ci_if_error: false
+          verbose: true

.github/workflows/pr.yaml

@@ -0,0 +1,62 @@
+name: Pull request
+on:
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  Lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.13"
+      - name: Install uv
+        uses: astral-sh/setup-uv@v8.1.0
+      - name: Install ruff
+        run: uv pip install ruff --system
+      - name: Check formatting and lint
+        run: make check-format
+
+  Test:
+    strategy:
+      matrix:
+        python-version: ["3.11", "3.13", "3.14"]
+      fail-fast: false
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v6
+      - name: Install uv
+        uses: astral-sh/setup-uv@v8.1.0
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v6
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: uv pip install -e ".[dev]" --system
+      - name: Run tests with coverage
+        run: make test
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v6
+        with:
+          files: ./coverage.xml
+          fail_ci_if_error: false
+          verbose: true
+
+  Build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v6
+      - name: Install uv
+        uses: astral-sh/setup-uv@v8.1.0
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.13"
+      - name: Install dependencies
+        run: uv pip install -e ".[dev]" --system
+      - name: Build package
+        run: make build

.github/workflows/versioning.yaml

@@ -0,0 +1,70 @@
+# Workflow that runs on versioning metadata updates.
+
+name: Versioning updates
+on:
+  push:
+      branches:
+        - main
+
+      paths:
+        - changelog.d/**
+        - "!pyproject.toml"
+
+jobs:
+    Versioning:
+        runs-on: ubuntu-latest
+        if: |
+          (!(github.event.head_commit.message == 'Update package version'))
+        steps:
+            - name: Generate GitHub App token
+              id: app-token
+              uses: actions/create-github-app-token@v3
+              with:
+                app-id: ${{ secrets.APP_ID }}
+                private-key: ${{ secrets.APP_PRIVATE_KEY }}
+            - name: Checkout repo
+              uses: actions/checkout@v6
+              with:
+                token: ${{ steps.app-token.outputs.token }}
+                fetch-depth: 0
+            - name: Setup Python
+              uses: actions/setup-python@v6
+              with:
+                python-version: 3.13
+            - name: Build changelog
+              run: |
+                pip install towncrier
+                python .github/bump_version.py
+                towncrier build --yes --version $(python -c "import re; print(re.search(r'version = \"(.+?)\"', open('pyproject.toml').read()).group(1))")
+            - name: Update changelog
+              uses: EndBug/add-and-commit@v10
+              with:
+                add: "."
+                message: Update package version
+                github_token: ${{ steps.app-token.outputs.token }}
+                fetch: false
+    publish-to-pypi:
+      name: Publish to PyPI
+      if: (github.event.head_commit.message == 'Update package version')
+      runs-on: ubuntu-latest
+      steps:
+        - name: Checkout code
+          uses: actions/checkout@v6
+          with:
+            fetch-depth: 0 # Fetch all history for all tags and branches
+        - name: Set up Python
+          uses: actions/setup-python@v6
+          with:
+            python-version: 3.13
+        - name: Install package
+          run: make install
+        - name: Build package
+          run: python -m build
+        - name: Publish a git tag
+          run: ".github/publish-git-tag.sh || true"
+        - name: Publish to PyPI
+          uses: pypa/gh-action-pypi-publish@release/v1
+          with:
+            user: __token__
+            password: ${{ secrets.PYPI }}
+            skip-existing: true

.gitignore

@@ -6,3 +6,6 @@ __pycache__/
 dist/
 build/
 *.egg-info/
+.coverage
+coverage.xml
+htmlcov/

CHANGELOG.md

@@ -0,0 +1,8 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+<!-- towncrier release notes start -->

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 PolicyEngine
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -0,0 +1,24 @@
+install:
+	pip install -e ".[dev]"
+
+test:
+	pytest tests/ --cov=microunit --cov-report=xml --maxfail=0 -v
+
+check-format:
+	ruff check .
+	ruff format --check .
+
+format:
+	ruff check --fix .
+	ruff format .
+
+build:
+	pip install build
+	python -m build
+
+changelog:
+	python .github/bump_version.py
+	towncrier build --yes --version $$(python -c "import re; print(re.search(r'version = \"(.+?)\"', open('pyproject.toml').read()).group(1))")
+
+clean:
+	rm -rf dist/ build/ *.egg-info/