Error Handling

TornOpen provides ClientError and ServerError for raising expected exceptions. Both ClientError and ServerError inherits from tornopen.models.HTTPJsonError.

Usage

from torn_open import AnnotatedHandler, ClientError, ResponseModel, Application


class AResponseModel(ResponseModel):
    """
    My response model
    """

    number: int


class ErrorHandler(AnnotatedHandler):
    async def get(self, number: str) -> AResponseModel:
        try:
            number = int(number)
        except ValueError as e:
            raise ClientError(
                status_code=400,
                error_type="invalid number",
            ) from e
        return AResponseModel(number=number)


application = Application([("/error", ErrorHandler)])

OpenAPI Specification

On application start, TornOpen parses the overridden HTTP methods for instantiations of ClientError and ServerError, and includes them in the OpenAPI Specifications. Note that ClientError or ServerError raised outside of the HTTP methods will not be reflected on the OpenAPI spec. Currently, only ClientError and ServerError are compatible with the AnnotatedHandler.

There are plans to generalize error handling and allowing users to define their own error classes.

paths:
  "/error":
    get:
      parameters:
      - name: number
        in: query
        required: true
        schema:
          type: string
      responses:
        '200':
          description: My response model
          content:
            application/json:
              schema:
                title: AResponseModel
                description: My response model
                type: object
                properties:
                  number:
                    title: Number
                    type: integer
                required:
                - number
        '400':
          description: invalid number
          content:
            application/json:
              schema:
                type: object
                properties:
                  status_code:
                    type: number
                  type:
                    type: string
                    enum:
                    - invalid number
                  message:
                    type: string
                required:
                - status_code
                - type
info:
  title: tornado-server
  version: 1.0.0
openapi: 3.0.0