flask_problem_detail.py

"""
A simple Flask error handler that turns exceptions into problem detail responses.
"""
from flask import Flask, current_app, jsonify
from werkzeug.exceptions import HTTPException, InternalServerError


def exception_to_problem_detail(exc: Exception):
    """
    Turn an exception into a problem detail response.

    https://tools.ietf.org/html/rfc7807
    """
    # Log any non-HTTP error loudly.
    if not isinstance(exc, HTTPException):
        exc = InternalServerError(f"{exc.__class__.__name__}: {exc}")
        exc_type, exc_value, tb = sys.exc_info()
        current_app.log_exception((exc_type, exc_value, tb))

    problem_detail = {
        "type": "about:blank",
        "status": exc.code,
        "title": exc.name,
        "detail": exc.description,
    }

    response = jsonify(problem_detail)
    response.status_code = exc.code
    response.content_type = "application/problem+json"
    return response


app.register_error_handler(Exception, exception_to_problem_detail)