create initial test for retry logic

Author: Coniferish

tests/test_utils_retries.py

@@ -0,0 +1,45 @@
+import os
+import pytest
+
+import requests_mock
+
+from unstructured_client import UnstructuredClient
+from unstructured_client.models import shared
+from unstructured_client.utils.retries import BackoffStrategy, RetryConfig
+
+
+def get_api_key():
+    api_key = os.getenv("UNS_API_KEY")
+    if api_key is None:
+        raise ValueError("UNS_API_KEY environment variable not set")
+    return api_key
+
+def test_backoff_strategy():
+    filename = "README.md"
+    backoff_strategy = BackoffStrategy(
+        initial_interval=100, max_interval=1000, exponent=1.5, max_elapsed_time=3000
+    )
+    retries = RetryConfig(
+        strategy="backoff", backoff=backoff_strategy, retry_connection_errors=True
+    )
+    
+    with requests_mock.Mocker() as mock:
+        # mock 500 status code for POST requests to the api 
+        mock.post("https://api.unstructured.io/general/v0/general", status_code=500)
+        session = UnstructuredClient(api_key_auth=get_api_key())
+
+        with open(filename, "rb") as f:
+            files=shared.Files(
+                content=f.read(),
+                file_name=filename,
+            )
+
+        req = shared.PartitionParameters(files=files)
+
+        with pytest.raises(Exception) as excinfo:
+            resp = session.general.partition(req, retries=retries)    
+            assert resp.status_code == 500
+            assert "API error occurred" in str(excinfo.value)
+
+        # the number of retries varies
+        assert len(mock.request_history) > 1