Generate Release Notes Markdown from PR Titles in Python

import json
from datetime import datetime, timezone

PRS = [
    {"title": "feat: add user login", "number": 12, "merged_at": "2025-01-10"},
    {"title": "fix: resolve payment timeout", "number": 13, "merged_at": "2025-01-11"},
    {"title": "chore: bump dependencies", "number": 14, "merged_at": "2025-01-12"},
    {"title": "feat: export CSV reports", "number": 15, "merged_at": "2025-01-13"},
    {"title": "fix: handle empty cart state", "number": 16, "merged_at": "2025-01-14"},
    {"title": "refactor: streamline auth middleware", "number": 17, "merged_at": "2025-01-15"},
]


def generate_release_notes(pull_requests):
    """Build Markdown release notes from a list of PR dicts."""
    sections = {}

    for pr in pull_requests:
        title = pr["title"]
        # Extract the conventional-commit type (before the first colon)
        if ": " in title:
            commit_type, description = title.split(": ", 1)
        else:
            commit_type, description = "misc", title

        # Map verbose types to release-note categories
        mapping = {
            "feat": "🚀 Features",
            "fix": "🐛 Bug Fixes",
            "refactor": "♻️ Refactors",
            "chore": "🧹 Maintenance",
        }
        section = mapping.get(commit_type, "📝 Other")
        item = f"- #{pr['number']} {description}"
        sections.setdefault(section, []).append(item)

    sorted_sections = sorted(sections.items(), key=lambda x: list(mapping.values()).index(x[0]) if x[0] in mapping.values() else len(mapping.values()))

    lines = ["# Release Notes", ""]
    for section, items in sorted_sections:
        lines.append(f"## {section}")
        lines.extend(items)
        lines.append("")

    lines.append("---")
    lines.append(f"*Generated on {datetime.now(timezone.utc).strftime('%Y-%m-%d %H:%M UTC')}*")
    return "\n".join(lines).strip()


if __name__ == "__main__":
    notes = generate_release_notes(PRS)
    print(notes)