Better Statement Generator

main.py

import typing as t
import logging
import random

from fastapi import Depends, FastAPI, Header, HTTPException
from fastapi.security.http import HTTPAuthorizationCredentials, HTTPBearer
from pydantic import BaseModel
from starlette import status

from os import environ


app = FastAPI()
# Placeholder for a database containing valid token values
known_tokens = set(["master-backup-token"])
# We will handle a missing token ourselves
get_bearer_token = HTTPBearer(auto_error=False)

api_key = environ.get("API_KEY", None)
if api_key is None:
    logging.warning("API_KEY environment variable is not set")
else:
    known_tokens.add(api_key)
    logging.info(f"Added API key from environment to known tokens")

# Use the api_key variable in your code as needed

class UnauthorizedMessage(BaseModel):
    detail: str = "Bearer token missing or unknown"

async def get_token(
    auth: t.Optional[HTTPAuthorizationCredentials] = Depends(get_bearer_token),
) -> str:
    # Simulate a database query to find a known token
    if auth is None or (token := auth.credentials) not in known_tokens:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=UnauthorizedMessage().detail,
        )
    return token


app = FastAPI(title="Better Statement Generator",
              description="Generate better statements by combining adjectives and nouns.",
              version="0.1.0",
              docs_url='/',
              redoc_url='/redoc',
              openapi_url='/openapi.json')

adjectives = ["red", "blue", "green", "small", "big"]
nouns = ["apple", "car", "tree", "dog", "cat"]

@app.get("/generate", response_model=str, responses={status.HTTP_401_UNAUTHORIZED: dict(model=UnauthorizedMessage)},)
def generate_pair(token: str = Depends(get_token)):
    adjective = random.choice(adjectives)
    noun = random.choice(nouns)
    return f"{adjective}-{noun}"

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)

requirements.txt

fastapi
uvicorn
# not really required for deployment but I'm being lazy
pytest
httpx

test_main.py

import pytest
from fastapi.testclient import TestClient
import os
from main import app

client = TestClient(app)

def test_generate_pair_with_valid_token():
    response = client.get("/generate", headers={"Authorization": "Bearer master-backup-token"})
    assert response.status_code == 200
    assert response.json() is not None

def test_generate_pair_with_invalid_token():
    response = client.get("/generate", headers={"Authorization": "Bearer invalid-token"})
    assert response.status_code == 401
    assert response.json() == {"detail": "Bearer token missing or unknown"}

def test_generate_pair_without_token():
    response = client.get("/generate")
    assert response.status_code == 401
    assert response.json() == {"detail": "Bearer token missing or unknown"}