Migrate from changelog_entry.yaml to towncrier fragments

.github/bump_version.py

@@ -0,0 +1,79 @@
+"""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/workflows/changelog_entry.yaml

@@ -1,29 +1,21 @@
-name: Versioning
+name: Changelog entry
 
 on:
   pull_request:
-    branches: [ main ]
+    branches: [main]
 
 jobs:
-  check-changelog-entry:
-    name: Changelog entry check
+  check-changelog:
+    name: Check changelog fragment
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-
-      - name: Check for changelog entry
+      - uses: actions/checkout@v4
+      - name: Check for changelog fragment
         run: |
-          if [ ! -f "changelog_entry.yaml" ]; then
-            echo "Error: changelog_entry.yaml file is missing."
-            echo "Please add a changelog_entry.yaml file at the root of the repository."
+          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
-
-          # Check if the file is empty
-          if [ ! -s "changelog_entry.yaml" ]; then
-            echo "Error: changelog_entry.yaml file is empty."
-            echo "Please add content to the changelog_entry.yaml file."
-            exit 1
-          fi
-
-          echo "Changelog entry found and is not empty."

.github/workflows/versioning.yaml

@@ -7,7 +7,7 @@ on:
         - main
 
       paths:
-        - changelog_entry.yaml
+        - changelog.d/**
         - "!pyproject.toml"
 
 jobs:
@@ -19,19 +19,20 @@ jobs:
             - name: Checkout repo
               uses: actions/checkout@v4
               with:
-                repository: ${{ github.event.pull_request.head.repo.full_name }}
-                ref: ${{ github.event.pull_request.head.ref }}
                 token: ${{ secrets.POLICYENGINE_GITHUB }}
+                fetch-depth: 0
             - name: Setup Python
               uses: actions/setup-python@v5
               with:
                 python-version: 3.12
-            - name: Build changelog
-              run: pip install yaml-changelog && make changelog
-            - name: Preview changelog update
-              run: ".github/get-changelog-diff.sh"
+            - name: Install towncrier
+              run: pip install towncrier
+            - name: Bump version and build changelog
+              run: |
+                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@v9
               with:
                 add: "."
-                message: Update package version
+                message: Update package version

Makefile

@@ -30,8 +30,5 @@ publish:
 	twine upload dist/*
 
 changelog:
-	build-changelog changelog.yaml --output changelog.yaml --update-last-date --start-from 1.0.0 --append-file changelog_entry.yaml
-	build-changelog changelog.yaml --org PolicyEngine --repo policyengine-us-data --output CHANGELOG.md --template .github/changelog_template.md
-	bump-version changelog.yaml pyproject.toml
-	rm changelog_entry.yaml || true
-	touch changelog_entry.yaml
+	python .github/bump_version.py
+	towncrier build --yes --version $$(python -c "import re; print(re.search(r'version = \"(.+?)\"', open('pyproject.toml').read()).group(1))")

changelog.d/migrate-to-towncrier.changed.md

@@ -0,0 +1 @@
+Migrated from changelog_entry.yaml to towncrier fragments to eliminate merge conflicts.