Migrate from changelog_entry.yaml to towncrier fragments

.github/bump_version.py

@@ -0,0 +1,74 @@
+"""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/pr.yaml

@@ -0,0 +1,21 @@
+name: Pull Request CI
+
+on:
+  pull_request:
+    branches: [main, master]
+
+jobs:
+  check-changelog:
+    name: Check changelog fragment
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - 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

Makefile

@@ -26,7 +26,8 @@ build:
 	python -m build
 
 changelog:
-	build-changelog changelog.yaml --output CHANGELOG.md --start-from 0.1.0
+	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:
 	find . -type f -name "*.pyc" -delete

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

@@ -0,0 +1 @@
+Migrate from changelog.yaml to towncrier fragments.

pyproject.toml

@@ -55,6 +55,7 @@ dev = [
     "plotly>=5.19.0",
     "ipykernel>=6.29.5",
     "ipywidgets>=8.1.5",
+    "towncrier>=24.0.0",
 ]
 
 [project.urls]
@@ -95,4 +96,35 @@ exclude = [
     "**/*.pyo",
     "**/.DS_Store",
     "**/Thumbs.db",
-]
+]
+
+[tool.towncrier]
+directory = "changelog.d"
+filename = "CHANGELOG.md"
+package_dir = "."
+title_format = "## {version}"
+
+[[tool.towncrier.type]]
+directory = "breaking"
+name = "Breaking changes"
+showcontent = true
+
+[[tool.towncrier.type]]
+directory = "added"
+name = "Added"
+showcontent = true
+
+[[tool.towncrier.type]]
+directory = "changed"
+name = "Changed"
+showcontent = true
+
+[[tool.towncrier.type]]
+directory = "fixed"
+name = "Fixed"
+showcontent = true
+
+[[tool.towncrier.type]]
+directory = "removed"
+name = "Removed"
+showcontent = true