Function validate_single_diagram

codewiki/src/be/utils.py:228–273

Validate a single mermaid diagram. Args: diagram_content: The mermaid diagram content diagram_num: Diagram number for error reporting line_start: Starting line number in the file Returns: Error message if invalid, empty string if valid

(diagram_content: str, diagram_num: int, line_start: int)

async def validate_single_diagram(diagram_content: str, diagram_num: int, line_start: int) -> str:
    """
    Validate a single mermaid diagram.

    Args:
        diagram_content: The mermaid diagram content
        diagram_num: Diagram number for error reporting
        line_start: Starting line number in the file

    Returns:
        Error message if invalid, empty string if valid
    """
    global _MERMAID_PY_BROKEN
    core_error = await _try_pythonmonkey_parse(diagram_content)
    if core_error is None:
        if _MERMAID_PY_BROKEN:
            # Validation disabled/unavailable is not a syntax error — a
            # non-empty return here would make callers report valid diagrams
            # as broken and send agents into fix loops.
            logger.debug("Diagram %d: validation skipped (mermaid-py disabled or unavailable)", diagram_num)
            return ""
        try:
            core_error = await asyncio.wait_for(
                asyncio.to_thread(_parse_via_mermaid_py, diagram_content),
                timeout=15.0,
            )
        except asyncio.TimeoutError:
            # Inconclusive, not a parse failure. Latch so the remaining
            # diagrams (and later calls) don't each block 15s on the same
            # broken Node.js setup.
            _MERMAID_PY_BROKEN = True
            logger.warning("Diagram %d: mermaid validation timed out (15s); skipping further validation", diagram_num)
            return ""
        except Exception as e:
            return f"  Diagram {diagram_num}: Exception during validation - {str(e)}"

    if not core_error:
        return ""

    line_match = re.search(r'line (\d+)', core_error)
    if line_match:
        error_line_in_diagram = int(line_match.group(1))
        actual_line_in_file = line_start + error_line_in_diagram
        newline = '\n'
        return f"Diagram {diagram_num}: Parse error on line {actual_line_in_file}:{newline}{newline.join(core_error.split(newline)[1:])}"
    return f"Diagram {diagram_num}: {core_error}"


if __name__ == "__main__":