Automatically Create Changelog Entry for PRs

.github/CHANGELOG_AUTOMATION.md

@@ -0,0 +1,36 @@
+# Automatic Changelog Generation
+
+This repository automatically generates changelog entries for new PRs using a GitHub Action.
+
+## How it works
+
+1. **Trigger**: When a PR is opened or edited
+2. **Processing**: The action runs a Python script that:
+   - Parses the `docs/changelog.md` file
+   - Finds the "## UNRELEASED" section
+   - Adds a new entry with format: `- PR_TITLE [#PR_NUMBER](PR_URL)`
+   - Checks for duplicates to avoid repeated entries
+3. **Update**: Commits the changes back to the PR branch
+
+## Files
+
+- `.github/workflows/update-changelog.yml` - GitHub Action workflow
+- `.github/scripts/update_changelog.py` - Python script that updates the changelog
+
+## Safety features
+
+- Only runs for PRs from the same repository (not forks)
+- Prevents infinite loops by excluding commits made by GitHub Action
+- Includes duplicate detection
+- Proper error handling and logging
+
+## Manual usage
+
+You can also run the script manually:
+
+```bash
+python .github/scripts/update_changelog.py \
+  --pr-number="123" \
+  --pr-title="My PR Title" \
+  --pr-url="https://github.com/egraphs-good/egglog-python/pull/123"
+```

.github/scripts/test_update_changelog.py

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+#!/usr/bin/env python3
+"""
+Simple test for the changelog update script.
+"""
+
+import os
+import tempfile
+import sys
+from pathlib import Path
+
+# Add the scripts directory to the path
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'scripts'))
+
+from update_changelog import update_changelog, find_unreleased_section
+
+
+def test_find_unreleased_section():
+    """Test finding the unreleased section."""
+    lines = [
+        "# Changelog\n",
+        "\n",
+        "## UNRELEASED\n",
+        "\n",
+        "- Some existing entry\n",
+        "\n",
+        "## 1.0.0\n",
+        "- Released version\n"
+    ]
+
+    unreleased_start, content_start = find_unreleased_section(lines)
+    assert unreleased_start == 2, f"Expected unreleased_start=2, got {unreleased_start}"
+    assert content_start == 4, f"Expected content_start=4, got {content_start}"
+    print("✓ find_unreleased_section test passed")
+
+
+def test_update_changelog():
+    """Test updating the changelog."""
+    # Create a temporary changelog file
+    changelog_content = """# Changelog
+
+## UNRELEASED
+
+- Existing entry
+
+## 1.0.0
+
+- Released version
+"""
+
+    with tempfile.NamedTemporaryFile(mode='w', suffix='.md', delete=False) as f:
+        f.write(changelog_content)
+        temp_path = f.name
+
+    try:
+        # Update the changelog
+        result = update_changelog(temp_path, "999", "Test PR", "https://example.com/pr/999")
+        assert result == True, "update_changelog should return True on success"
+
+        # Read the updated content
+        with open(temp_path, 'r') as f:
+            updated_content = f.read()
+
+        # Check that the entry was added
+        assert "- Test PR [#999](https://example.com/pr/999)" in updated_content
+
+        # Check that it was added in the right place (after UNRELEASED)
+        lines = updated_content.split('\n')
+        unreleased_idx = lines.index("## UNRELEASED")
+        entry_idx = None
+        for i, line in enumerate(lines):
+            if "Test PR [#999]" in line:
+                entry_idx = i
+                break
+
+        assert entry_idx is not None, "Entry should be found"
+        assert entry_idx > unreleased_idx, "Entry should be after UNRELEASED section"
+
+        # Test duplicate detection
+        result2 = update_changelog(temp_path, "999", "Test PR", "https://example.com/pr/999")
+        assert result2 == False, "update_changelog should return False for duplicates"
+
+        print("✓ update_changelog test passed")
+
+    finally:
+        # Clean up
+        os.unlink(temp_path)
+
+
+def main():
+    """Run all tests."""
+    print("Running changelog automation tests...")
+
+    test_find_unreleased_section()
+    test_update_changelog()
+
+    print("✓ All tests passed!")
+
+
+if __name__ == '__main__':
+    main()

.github/scripts/update_changelog.py

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+#!/usr/bin/env python3
+"""
+Script to automatically update the changelog with PR information.
+"""
+
+import argparse
+import re
+import sys
+from pathlib import Path
+
+
+def find_unreleased_section(lines):
+    """Find the line number where UNRELEASED section starts and ends."""
+    unreleased_start = None
+    content_start = None
+
+    for i, line in enumerate(lines):
+        if line.strip() == "## UNRELEASED":
+            unreleased_start = i
+            continue
+
+        if unreleased_start is not None and content_start is None:
+            # Skip empty lines after ## UNRELEASED
+            if line.strip() == "":
+                continue
+            else:
+                content_start = i
+                break
+
+    return unreleased_start, content_start
+
+
+def update_changelog(changelog_path, pr_number, pr_title, pr_url):
+    """Update the changelog with the new PR entry."""
+
+    # Read the current changelog
+    with open(changelog_path, 'r', encoding='utf-8') as f:
+        lines = f.readlines()
+
+    # Find the UNRELEASED section
+    unreleased_start, content_start = find_unreleased_section(lines)
+
+    if unreleased_start is None:
+        print("ERROR: Could not find '## UNRELEASED' section in changelog")
+        return False
+
+    if content_start is None:
+        print("ERROR: Could not find content start after UNRELEASED section")
+        return False
+
+    # Create the new entry
+    new_entry = f"- {pr_title} [#{pr_number}]({pr_url})\n"
+
+    # Check if this PR entry already exists to avoid duplicates
+    for line in lines[content_start:]:
+        if f"[#{pr_number}]" in line:
+            print(f"Changelog entry for PR #{pr_number} already exists")
+            return False
+        # Stop checking when we reach the next section
+        if line.startswith("## ") and not line.strip() == "## UNRELEASED":
+            break
+
+    # Insert the new entry at the beginning of the unreleased content
+    lines.insert(content_start, new_entry)
+
+    # Write the updated changelog
+    with open(changelog_path, 'w', encoding='utf-8') as f:
+        f.writelines(lines)
+
+    print(f"Added changelog entry for PR #{pr_number}: {pr_title}")
+    return True
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Update changelog with PR information')
+    parser.add_argument('--pr-number', required=True, help='Pull request number')
+    parser.add_argument('--pr-title', required=True, help='Pull request title')
+    parser.add_argument('--pr-url', required=True, help='Pull request URL')
+    parser.add_argument('--changelog-path', default='docs/changelog.md', help='Path to changelog file')
+
+    args = parser.parse_args()
+
+    changelog_path = Path(args.changelog_path)
+
+    if not changelog_path.exists():
+        print(f"ERROR: Changelog file not found: {changelog_path}")
+        sys.exit(1)
+
+    success = update_changelog(changelog_path, args.pr_number, args.pr_title, args.pr_url)
+
+    if not success:
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    main()

.github/workflows/update-changelog.yml

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+name: Update Changelog
+
+on:
+  pull_request:
+    types: [opened, edited]
+
+jobs:
+  update-changelog:
+    # Only run if this is not a PR from a fork to avoid permission issues
+    # and not a commit made by GitHub Action to avoid infinite loops
+    if: github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'github-actions[bot]'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          # Checkout the PR head ref
+          ref: ${{ github.event.pull_request.head.ref }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Test changelog script
+        run: python .github/scripts/test_update_changelog.py
+
+      - name: Update changelog
+        run: |
+          python .github/scripts/update_changelog.py \
+            --pr-number="${{ github.event.pull_request.number }}" \
+            --pr-title="${{ github.event.pull_request.title }}" \
+            --pr-url="${{ github.event.pull_request.html_url }}"
+
+      - name: Check for changes
+        id: changes
+        run: |
+          if git diff --quiet docs/changelog.md; then
+            echo "changed=false" >> $GITHUB_OUTPUT
+          else
+            echo "changed=true" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Commit and push changes
+        if: steps.changes.outputs.changed == 'true'
+        run: |
+          git config --local user.email "action@github.com"
+          git config --local user.name "GitHub Action"
+          git add docs/changelog.md
+          git commit -m "Add changelog entry for PR #${{ github.event.pull_request.number }}"
+          git push

docs/changelog.md

@@ -4,6 +4,8 @@ _This project uses semantic versioning_
 
 ## UNRELEASED
 
+- [WIP] Automatically Generate Changelog Entries for PRs [#313](https://github.com/egraphs-good/egglog-python/pull/313)
+- Automatically Generate Changelog Entries for PRs [#312](https://github.com/egraphs-good/egglog-python/pull/312)
 - Upgrade egglog which includes new backend.
   - Fixes implementation of the Python Object sort to work with objects with dupliating hashes but the same value.
     Also changes the representation to be an index into a list instead of the ID, making egglog programs more deterministic.