add excpetion_handlers module

Author: grillazz

app/exception handlers/__init__.py

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+from app.exception_handlers.registry import register_exception_handlers
+
+__all__ = ["register_exception_handlers"]

app/exception_handlers/__init__.py

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+# app/exception_handlers/base.py
+import orjson
+from fastapi import Request
+from fastapi.responses import JSONResponse
+from rotoger import AppStructLogger
+
+logger = AppStructLogger().get_logger()
+
+
+class BaseExceptionHandler:
+    """Base class for all exception handlers with common functionality."""
+
+    @staticmethod
+    async def extract_request_info(request: Request):
+        """Extract common request information."""
+        request_path = request.url.path
+        try:
+            raw_body = await request.body()
+            request_body = orjson.loads(raw_body) if raw_body else None
+        except orjson.JSONDecodeError:
+            request_body = None
+
+        return request_path, request_body
+
+    @classmethod
+    async def log_error(cls, message, request_info, **kwargs):
+        """Log error with standardized format."""
+        request_path, request_body = request_info
+        await logger.aerror(
+            message,
+            request_url=request_path,
+            request_body=request_body,
+            **kwargs
+        )

app/exception_handlers/base.py

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+from fastapi import Request
+from fastapi.responses import JSONResponse
+from sqlalchemy.exc import SQLAlchemyError
+
+from app.exception_handlers.base import BaseExceptionHandler
+
+
+class SQLAlchemyExceptionHandler(BaseExceptionHandler):
+    """Handles SQLAlchemy database exceptions."""
+
+    @classmethod
+    async def handle_exception(cls, request: Request, exc: SQLAlchemyError) -> JSONResponse:
+        request_info = await cls.extract_request_info(request)
+
+        await cls.log_error(
+            "Database error occurred",
+            request_info,
+            sql_error=repr(exc)
+        )
+
+        return JSONResponse(
+            status_code=500,
+            content={"message": "A database error occurred. Please try again later."}
+        )

app/exception_handlers/database.py

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+from fastapi import FastAPI
+from sqlalchemy.exc import SQLAlchemyError
+from fastapi.exceptions import ResponseValidationError
+
+from app.exception_handlers.database import SQLAlchemyExceptionHandler
+from app.exception_handlers.validation import ResponseValidationExceptionHandler
+
+def register_exception_handlers(app: FastAPI) -> None:
+    """Register all exception handlers with the FastAPI app."""
+    app.add_exception_handler(SQLAlchemyError, SQLAlchemyExceptionHandler.handle_exception)
+    app.add_exception_handler(ResponseValidationError, ResponseValidationExceptionHandler.handle_exception)

app/exception_handlers/registry.py

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+from fastapi import Request
+from fastapi.exceptions import ResponseValidationError
+from fastapi.responses import JSONResponse
+
+from app.exception_handlers.base import BaseExceptionHandler
+
+
+class ResponseValidationExceptionHandler(BaseExceptionHandler):
+    """Handles response validation exceptions."""
+
+    @classmethod
+    async def handle_exception(cls, request: Request, exc: ResponseValidationError) -> JSONResponse:
+        request_info = await cls.extract_request_info(request)
+        errors = exc.errors()
+
+        # Check if this is a None/null response case
+        is_none_response = False
+        for error in errors:
+            if error.get("input") is None and "valid dictionary" in error.get("msg", ""):
+                is_none_response = True
+                break
+
+        await cls.log_error(
+            "Response validation error occurred",
+            request_info,
+            validation_errors=errors,
+            is_none_response=is_none_response
+        )
+
+        if is_none_response:
+            return JSONResponse(
+                status_code=404,
+                content={"no_response": "The requested resource was not found"}
+            )
+        else:
+            return JSONResponse(
+                status_code=422,
+                content={"response_format_error": errors}
+            )