Deskaid

#!/usr/bin/env python3 import re from typing import List, Tuple # Compile regexes once at module level for better performance TRAILER_RE = re.compile(r"^([A-Za-z0-9_-]+)(\s*:\s*)(.*)$") CONTINUATION_RE = re.compile(r"^\s+\S.*$") DIVIDER_RE = re.compile(r"^---") # Git-generated trailer prefixes GIT_GENERATED_PREFIXES = ["Signed-off-by: ", "(cherry picked from commit "] def parse_message(message: str) -> Tuple[str, str, str]: """ Parse a Git commit message into subject, body, and trailers. According to the Git documentation, trailers are: - A group of one or more lines that is all trailers, or contains at least one Git-generated or user-configured trailer and consists of at least 25% trailers. - The group must be preceded by one or more empty (or whitespace-only) lines. - The group must either be at the end of the message or be the last non-whitespace lines before a line that starts with "---" (the "divider"). Args: message: The commit message to parse. Returns: A tuple containing: - subject: The first line of the message - body: The body of the message (may be empty) - trailers: The trailer block as a raw string (may be empty) """ if not message: return "", "", "" # Split into lines and get the subject (first line) lines = message.splitlines() subject = lines[0] if lines else "" if len(lines) <= 1: return subject, "", "" # Find the divider line (---) and use only the content before it message_end = next( (i for i, line in enumerate(lines) if DIVIDER_RE.match(line)), len(lines) ) message_lines = lines[1:message_end] if not message_lines: return subject, "", "" # Find where the trailer block starts trailer_start = find_trailer_block_start(message_lines) if trailer_start == -1: # No trailer block found, everything after subject is body body = "\n".join(message_lines).strip() return subject, body, "" # Body is everything between subject and trailers (with empty lines trimmed) body = "\n".join(message_lines[:trailer_start]).strip() # Keep trailers as a raw string trailers = "\n".join(message_lines[trailer_start:]).strip() return subject, body, trailers def find_trailer_block_start(lines: List[str]) -> int: """ Find the start index of the trailer block in a list of lines. Args: lines: List of message lines (without subject and divider). Returns: Index of the first line of the trailer block, or -1 if no trailer block is found. """ # Remove trailing empty lines trimmed_lines = list(reversed([line for line in reversed(lines) if line.strip()])) if not trimmed_lines: return -1 # Find the last non-empty block block_indices = [-1] + [i for i, line in enumerate(lines) if not line.strip()] # Try blocks from last to first for i in range(len(block_indices) - 1, -1, -1): start_idx = block_indices[i] + 1 # If we're at the beginning or checking the whole message if i == 0 or start_idx == 0: # Check if the whole remaining content is a trailer block if is_trailer_block(lines[start_idx:]): return start_idx # No more blocks to check return -1 # Check if the block after this blank line is a trailer block end_idx = block_indices[i + 1] if i + 1 < len(block_indices) else len(lines) if is_trailer_block(lines[start_idx:end_idx]): return start_idx return -1 def is_trailer_block(lines: List[str]) -> bool: """ Determine if the given lines form a trailer block. A block is a trailer block if: 1. All lines are trailers, or 2. At least one Git-generated trailer exists and at least 25% of lines are trailers Args: lines: List of lines to check. Returns: True if the lines form a trailer block, False otherwise. """ # Filter out empty lines content_lines = [line for line in lines if line.strip()] if not content_lines: return False trailer_lines = 0 non_trailer_lines = 0 has_git_generated_trailer = False i = 0 while i < len(content_lines): line = content_lines[i] # Skip continuation lines (they belong to the previous trailer) if CONTINUATION_RE.match(line): i += 1 continue # Check if it's a git-generated trailer if any(line.startswith(prefix) for prefix in GIT_GENERATED_PREFIXES): has_git_generated_trailer = True trailer_lines += 1 elif TRAILER_RE.match(line): # Regular trailer trailer_lines += 1 else: # Not a trailer line non_trailer_lines += 1 i += 1 # A block is a trailer block if all lines are trailers OR # it has at least one git-generated trailer and >= 25% of lines are trailers return (trailer_lines > 0 and non_trailer_lines == 0) or ( has_git_generated_trailer and trailer_lines * 3 >= non_trailer_lines )