different exception handling. not really happy yet

apiserver/main.py

@@ -2,8 +2,9 @@ from datetime import timedelta
 from enum import Enum
 from typing import Dict, Optional
 
-from fastapi import FastAPI, HTTPException, status
+from fastapi import FastAPI, HTTPException, status, Request
 from fastapi.param_functions import Depends
+from fastapi.responses import JSONResponse
 from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
 
 from .config import ApiserverSettings
@@ -43,13 +44,8 @@ oauth2_scheme = OAuth2PasswordBearer(tokenUrl=ReservedPaths.TOKEN)
 def my_user(token=Depends(oauth2_scheme)):
     return get_current_user(token, userdb)
 
-
 def my_auth(form_data: OAuth2PasswordRequestForm = Depends()):
-    try:
     return authenticate_user(userdb, form_data.username, form_data.password)
-    except:
-        return None
-
     
 @app.get("/")
 async def get_types():
@@ -98,12 +94,7 @@ async def add_dataset(location_data_type: LocationDataType,
 @app.get("/{location_data_type}/{dataset_id}")
 async def get_specific_dataset(location_data_type: LocationDataType, dataset_id: str):
     # returns all information about a specific dataset, identified by id
-    try:
     return adapter.get_details(location_data_type, dataset_id)
-    except FileNotFoundError:
-        raise HTTPException(
-            status_code=404, 
-            detail=f"The provided id={dataset_id} does not exist for this datatype.")
     
 
 @app.put("/{location_data_type}/{dataset_id}")
@@ -111,12 +102,8 @@ async def update_specific_dataset(location_data_type: LocationDataType,
                                   dataset_id: str, dataset: LocationData,
                                   user: User = Depends(my_user)):
     # update the information about a specific dataset, identified by id
-    try:
+   
     return adapter.update_details(location_data_type, dataset_id, dataset, user.username)
-    except FileNotFoundError:
-        raise HTTPException(
-            status_code=404, 
-            detail=f"The provided id={dataset_id} does not exist for this datatype.")
     
 
 @app.delete("/{location_data_type}/{dataset_id}")
@@ -124,9 +111,12 @@ async def delete_specific_dataset(location_data_type: LocationDataType,
                                   dataset_id: str,
                                   user: str = Depends(my_user)):
     # delete a specific dataset
-    try:
+    # TODO: 404 is the right answer? 204 could also be the right one
     return adapter.delete(location_data_type, dataset_id, user.username)
-    except FileNotFoundError:
-        raise HTTPException(
-            status_code=404, 
-            detail=f"The provided id={dataset_id} does not exist for this datatype.")
+    
+
+@app.exception_handler(FileNotFoundError)
+async def not_found_handler(request: Request, exc: FileNotFoundError):
+    oid=request.path_params.get('dataset_id', '')
+    return JSONResponse(status_code=status.HTTP_404_NOT_FOUND, 
+                        content={'message':f"Object {oid} does not exist"})
\ No newline at end of file

apiserver/security/user.py

@@ -28,10 +28,6 @@ class Token(BaseModel):
     token_type: str
 
 
-class TokenData(BaseModel):
-    username: Optional[str] = None
-
-
 class User(BaseModel):
     username: str
     email: str = None
@@ -86,7 +82,7 @@ class JsonDBInterface(AbstractDBInterface):
     def get(self, username: str):
         data = self.__read_all()
         if username not in data:
-            raise Exception(f"User {username} not in database {self.filePath}")
+            return None
         
         return UserInDB(**data[username])
 
@@ -119,11 +115,9 @@ def get_password_hash(password):
 
 def authenticate_user(userdb: AbstractDBInterface, username: str, password: str):
     user: UserInDB = get_user(userdb, username)
-    if not user:
-        return False
-    if not verify_password(password, user.hashed_password):
-        return False
+    if user and verify_password(password, user.hashed_password):
         return user
+    return None
 
 
 def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
@@ -140,22 +134,19 @@ def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
 def get_user(db: AbstractDBInterface, username: str):
     return db.get(username)
 
-
-def get_current_user(token: str, userdb: AbstractDBInterface):
 credentials_exception = HTTPException(
         status_code=status.HTTP_401_UNAUTHORIZED,
         detail="Could not validate credentials",
         headers={"WWW-Authenticate": "Bearer"},
     )
+    
+def get_current_user(token: str, userdb: AbstractDBInterface):
     try:
         payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
         username: str = payload.get("sub")
-        if username is None:
+        if (username is None) or ((user:=get_user(userdb, username)) is None):
             raise credentials_exception
-        token_data = TokenData(username=username)
+        
+        return user
     except JWTError:
         raise credentials_exception
-    user = get_user(userdb, token_data.username)
-    if user is None:
-        raise credentials_exception
-    return user

tests/user_tests/test_user.py

@@ -31,7 +31,8 @@ class UserTests(unittest.TestCase):
         self.assertListEqual(lst, [], 'Should be empty')
 
     def test_empty_get(self):
-        self.assertRaises(Exception, self.userdb.get, 'foo')
+        #self.assertRaises(Exception, self.userdb.get, 'foo')
+        self.assertIsNone(self.userdb.get('foo'))
         
     def test_adding(self):