Awesome Exception

A library designed to handle http exception elegantly with customization support like i18n support.

Feature

• common http exception class that support custom message and status code

Usage

Installation

1. pip install awesome-exception

Exceptions

Using fast API as example, we may simply throw exception with a proper status code, and an optional error code. We may also supply arbitrary key value in args dict, to help frontend render better error message.

from awesome_exception.exceptions import NotFound
from fastapi import APIRouter

router = APIRouter()


@router.get('/transactions')
def get(id: str):
    try:
        obj = find_by_id(id)
    except Exception as e:
        raise NotFound(message='transaction not found' % id, error_code='A0001', args={id: id})
    ...

And we may implement a common error handler to convert all these errors to proper response schema

from awesome_exception.exceptions import HTTPException
from fastapi.requests import Request
from fastapi.responses import JSONResponse


@app.exception_handler(HTTPException)
async def http_exception_handler(request: Request, exc: HTTPException):
    return JSONResponse(
        status_code=exc.status_code,
        content={
            'detail': exc.detail,
            'error_code': exc.error_code,
        }
    )

This would result in a response with status code 404, and body

{
  "status_code": 404,
  "detail": {
    "message": "transaction not found",
    "id": "some_id"
  },
  "error_code": "A0001"
}

With this response, frontend can decide to simply render detail, or map it to detailed message. If error_code "A0001" correspond to the following i18 n entry

"error.A0001": {"en-US": "transaction can not be found with supplied {id}: {message}"}

we may format message accordingly with

errorMessage = formatMessage({ id: `error.${error.data.error_code}` }, error.data.detail);

Note that error code is not supplied, is default to status code. So it is always safe to simply use error_code in frontend to decide what to render.

Development

Installing Poetry

1. create your own environment for poetry, and simply run: pip install poetry
2. alternatively, you can refer to poetry's official page
3. to be able to use poe directly, pip install poethepoet

Contributing

1. project setup: poetry install
2. create your own branch to start developing new feature.
3. before creating pr, make sure you pass poe lint and poe test.
   • what happened inside poe test is that a minio server is setup for you temporarily, and teardown and unit test is finished.
   • notice that poe test would also work if you already have a minio up and running. You need the following env variable: MINIO_ACCESS_KEY, MINIO_SECRET_KEY, MINIO_ADDRESS upon running poe test.
4. for a list of available poe command, poe
5. after you submit a pr, you should check if pipeline is successful.

Releasing

1. poetry version [new_version]
2. git commit -m"Bump version"
3. git push origin develop
4. create new release on github.
5. Create release off develop branch, auto generate notes, and review release note.
6. Publish release