feat: add error handling

src/codeocean/__init__.py

@@ -1 +1,2 @@
 from codeocean.client import CodeOcean  # noqa: F401
+from codeocean.error import Error  # noqa: F401

src/codeocean/client.py

@@ -5,10 +5,12 @@
 from requests_toolbelt.sessions import BaseUrlSession
 from typing import Optional
 from urllib3.util import Retry
+import requests
 
 from codeocean.capsule import Capsules
 from codeocean.computation import Computations
 from codeocean.data_asset import DataAssets
+from codeocean.error import Error
 
 
 @dataclass
@@ -45,11 +47,15 @@ def __post_init__(self):
         })
         if self.agent_id:
             self.session.headers.update({"Agent-Id": self.agent_id})
-        self.session.hooks["response"] = [
-            lambda response, *args, **kwargs: response.raise_for_status()
-        ]
+        self.session.hooks["response"] = [self._error_handler]
         self.session.mount(self.domain, TCPKeepAliveAdapter(max_retries=self.retries))
 
         self.capsules = Capsules(client=self.session)
         self.computations = Computations(client=self.session)
         self.data_assets = DataAssets(client=self.session)
+
+    def _error_handler(self, response, *args, **kwargs):
+        try:
+            response.raise_for_status()
+        except requests.HTTPError as err:
+            raise Error(err) from err

src/codeocean/error.py

@@ -0,0 +1,41 @@
+from __future__ import annotations
+
+import json
+import requests
+
+
+class Error(Exception):
+    """
+    Represents an HTTP error with additional context extracted from the response.
+
+    Attributes:
+        http_err (requests.HTTPError): The HTTP error object.
+        status_code (int): The HTTP status code of the error response.
+        message (str): A message describing the error, extracted from the response body.
+        data (Any): If the response body is json, this attribute contains the json object; otherwise, it is None.
+
+    Args:
+        err (requests.HTTPError): The HTTP error object.
+    """
+    def __init__(self, err: requests.HTTPError):
+        self.http_err = err
+        self.status_code = err.response.status_code
+        self.message = "An error occurred."
+        self.data = None
+
+        try:
+            self.data = err.response.json()
+            if isinstance(self.data, dict):
+                self.message = self.data.get("message", self.message)
+        except Exception:
+            # response wasn't JSON – fall back to text
+            self.message = err.response.text
+
+        super().__init__(self.message)
+
+    def __str__(self) -> str:
+        msg = str(self.http_err)
+        msg += f"\n\nMessage: {self.message}"
+        if self.data:
+            msg += "\n\nData:\n" + json.dumps(self.data, indent=2)
+        return msg

tests/test_error.py

@@ -0,0 +1,140 @@
+import unittest
+from unittest.mock import Mock
+import requests
+
+from codeocean.error import Error
+
+
+class TestError(unittest.TestCase):
+    """Test cases for the Error exception class."""
+
+    def test_error_is_exception_subclass(self):
+        """Test that Error is a subclass of Exception."""
+        self.assertTrue(issubclass(Error, Exception))
+
+    def test_error_with_json_dict(self):
+        """Test Error creation with JSON dict response containing message."""
+        # Create mock HTTPError and response
+        mock_response = Mock()
+        mock_response.status_code = 400
+        mock_response.json.return_value = {"message": "Custom error message", "datasets": [{"id": "123", "name": "tv"}]}
+
+        mock_http_error = Mock(spec=requests.HTTPError)
+        mock_http_error.response = mock_response
+
+        # Create Error instance
+        error = Error(mock_http_error)
+
+        # Verify attributes
+        self.assertEqual(error.status_code, 400)
+        self.assertEqual(error.message, "Custom error message")
+        self.assertEqual(error.data, {"message": "Custom error message", "datasets": [{"id": "123", "name": "tv"}]})
+
+    def test_error_with_json_dict_no_message(self):
+        """Test Error creation with JSON dict response without message field."""
+        # Create mock HTTPError and response
+        mock_response = Mock()
+        mock_response.status_code = 500
+        mock_response.json.return_value = {"error": "some other field"}
+
+        mock_http_error = Mock(spec=requests.HTTPError)
+        mock_http_error.response = mock_response
+
+        # Create Error instance
+        error = Error(mock_http_error)
+
+        # Verify attributes
+        self.assertEqual(error.status_code, 500)
+        self.assertEqual(error.message, "An error occurred.")
+        self.assertEqual(error.data, {"error": "some other field"})
+
+    def test_error_with_json_list(self):
+        """Test Error creation with JSON list response."""
+        # Create mock HTTPError and response
+        mock_response = Mock()
+        mock_response.status_code = 403
+        mock_response.json.return_value = [{"field": "error1"}, {"field": "error2"}]
+
+        mock_http_error = Mock(spec=requests.HTTPError)
+        mock_http_error.response = mock_response
+
+        # Create Error instance
+        error = Error(mock_http_error)
+
+        # Verify attributes
+        self.assertEqual(error.status_code, 403)
+        self.assertEqual(error.message, "An error occurred.")
+        self.assertEqual(error.data, [{"field": "error1"}, {"field": "error2"}])
+
+    def test_error_with_non_json_response(self):
+        """Test Error creation when response is not JSON."""
+        # Create mock HTTPError and response
+        mock_response = Mock()
+        mock_response.status_code = 404
+        mock_response.json.side_effect = Exception("Not JSON")
+        mock_response.text = "Page not found"
+
+        mock_http_error = Mock(spec=requests.HTTPError)
+        mock_http_error.response = mock_response
+
+        # Create Error instance
+        error = Error(mock_http_error)
+
+        # Verify attributes
+        self.assertEqual(error.status_code, 404)
+        self.assertEqual(error.message, "Page not found")
+        self.assertIsNone(error.data)
+
+    def test_error_str_method_with_data(self):
+        """Test Error __str__ method when data is present."""
+        # Create mock HTTPError and response
+        mock_response = Mock()
+        mock_response.status_code = 400
+        mock_response.json.return_value = {"message": "Validation failed", "errors": ["field1", "field2"]}
+
+        mock_http_error = Mock(spec=requests.HTTPError)
+        mock_http_error.response = mock_response
+        mock_http_error.__str__ = Mock(return_value="400 Client Error: Bad Request for url: http://example.com")
+
+        # Create Error instance
+        error = Error(mock_http_error)
+
+        # Test __str__ method
+        error_str = str(error)
+
+        # Verify the string contains expected components
+        self.assertEqual(error_str, """400 Client Error: Bad Request for url: http://example.com
+
+Message: Validation failed
+
+Data:
+{
+  "message": "Validation failed",
+  "errors": [
+    "field1",
+    "field2"
+  ]
+}""")
+
+    def test_error_str_method_without_data(self):
+        """Test Error __str__ method when data is None."""
+        # Create mock HTTPError and response
+        mock_response = Mock()
+        mock_response.status_code = 404
+        mock_response.json.side_effect = Exception("Not JSON")
+        mock_response.text = "Page not found"
+
+        mock_http_error = Mock(spec=requests.HTTPError)
+        mock_http_error.response = mock_response
+        mock_http_error.__str__ = Mock(return_value="404 Client Error: Not Found for url: http://example.com")
+
+        # Create Error instance
+        error = Error(mock_http_error)
+
+        # Test __str__ method
+        error_str = str(error)
+
+        # Verify the string contains expected components
+        self.assertEqual(error_str, """404 Client Error: Not Found for url: http://example.com
+
+Message: Page not found""")