MNT: Add retry logic and better exception handling (#294)

Author: greglucas

imap_data_access/io.py

@@ -24,6 +24,9 @@ class IMAPDataAccessError(Exception):
     pass
 
 
+_RETRY_ADAPTER = requests.adapters.HTTPAdapter(max_retries=3)
+
+
 @contextlib.contextmanager
 def _make_request(request: requests.PreparedRequest):
     """Get the response from a URL request using the requests library.
@@ -44,6 +47,7 @@ def _make_request(request: requests.PreparedRequest):
         )
     try:
         with requests.Session() as session:
+            session.mount("https://", _RETRY_ADAPTER)
             response = session.send(request)
             response.raise_for_status()
             yield response
@@ -52,8 +56,8 @@ def _make_request(request: requests.PreparedRequest):
         error_msg = f"{e.response.status_code} {e.response.reason}: {e.response.text}"
         raise IMAPDataAccessError(error_msg) from e
     except requests.exceptions.RequestException as e:
-        error_msg = f"{e.response.status_code} {e.response.reason}: {e.response.text}"
-        raise IMAPDataAccessError(error_msg) from e
+        # Handle cases where response may not exist (connection errors, timeouts, etc.)
+        raise IMAPDataAccessError(str(e)) from e
 
 
 def _get_base_url() -> str:

tests/test_io.py

@@ -97,15 +97,12 @@ def test_request_errors(mock_send_request):
     with pytest.raises(imap_data_access.io.IMAPDataAccessError, match="404 Not Found"):
         imap_data_access.download(test_science_path)
 
-    # Set up the mock to raise a RequestException
-    mock_response.status_code = 400
-    mock_response.reason = "Request failed"
-    mock_response.text = ""
+    # Set up the mock to raise a RequestException with a response
     mock_send_request.side_effect = requests.exceptions.RequestException(
-        response=mock_response
+        "connection error"
     )
     with pytest.raises(
-        imap_data_access.io.IMAPDataAccessError, match="400 Request failed"
+        imap_data_access.io.IMAPDataAccessError, match="connection error"
     ):
         imap_data_access.download(test_science_path)