whoops

notifications_python_client/errors.py

@@ -0,0 +1,90 @@
+from typing import List, Union  # noqa: UP035 – Python <3.10 compatibility
+
+from requests import RequestException, Response
+
+REQUEST_ERROR_STATUS_CODE = 503
+REQUEST_ERROR_MESSAGE = "Request failed"
+
+TOKEN_ERROR_GUIDANCE = "See our requirements for JSON Web Tokens \
+    at https://docs.notifications.service.gov.uk/rest-api.html#authorisation-header"
+TOKEN_ERROR_DEFAULT_ERROR_MESSAGE = "Invalid token: " + TOKEN_ERROR_GUIDANCE
+
+
+class TokenError(Exception):
+    def __init__(self, message=None, token=None):
+        self.message = (
+            message + ". " + TOKEN_ERROR_GUIDANCE
+            if message
+            else TOKEN_ERROR_DEFAULT_ERROR_MESSAGE
+        )
+        self.token = token
+
+
+class TokenExpiredError(TokenError):
+    pass
+
+
+class TokenAlgorithmError(TokenError):
+    def __init__(self):
+        super().__init__("Invalid token: algorithm used is not HS256")
+
+
+class TokenDecodeError(TokenError):
+    def __init__(self, message=None):
+        super().__init__(message or "Invalid token: signature")
+
+
+class TokenIssuerError(TokenDecodeError):
+    def __init__(self):
+        super().__init__("Invalid token: iss field not provided")
+
+
+class TokenIssuedAtError(TokenDecodeError):
+    def __init__(self):
+        super().__init__("Invalid token: iat field not provided")
+
+
+class APIError(Exception):
+    def __init__(self, response: Response = None, message: str = None):
+        self.response = response
+        self._message = message
+
+    def __str__(self):
+        return f"{self.status_code} - {self.message}"
+
+    @property
+    def message(
+        self,
+    ) -> Union[str, List[dict]]:  # noqa: UP006, UP007 – Python <3.10 compatibility
+        try:
+            json_resp = self.response.json()  # type: ignore
+            return json_resp.get("message", json_resp.get("errors"))
+        except (TypeError, ValueError, AttributeError, KeyError):
+            return self._message or REQUEST_ERROR_MESSAGE
+
+    @property
+    def status_code(self) -> int:
+        try:
+            return self.response.status_code  # type: ignore
+        except AttributeError:
+            return REQUEST_ERROR_STATUS_CODE
+
+
+class HTTPError(APIError):
+    @staticmethod
+    def create(e: RequestException) -> "HTTPError":
+        error = HTTPError(e.response)
+        if error.status_code == 503:
+            error = HTTP503Error(e.response)
+        return error
+
+
+class HTTP503Error(HTTPError):
+    """Specific instance of HTTPError for 503 errors
+
+    Used for detecting whether failed requests should be retried.
+    """
+
+
+class InvalidResponse(APIError):
+    pass