fix: fall back when payload compression fails

.sampo/changesets/doughty-princess-loviatar.md

@@ -0,0 +1,5 @@
+---
+pypi/posthog: patch
+---
+
+Fall back to uncompressed uploads when gzip compression fails

posthog/request.py

@@ -240,13 +240,16 @@ def post(
     log.debug("making request: %s to url: %s", data, url)
     headers = {"Content-Type": "application/json", "User-Agent": USER_AGENT}
     if gzip:
-        headers["Content-Encoding"] = "gzip"
-        buf = BytesIO()
-        with GzipFile(fileobj=buf, mode="w") as gz:
-            # 'data' was produced by json.dumps(),
-            # whose default encoding is utf-8.
-            gz.write(cast(str, data).encode("utf-8"))
-        data = buf.getvalue()
+        try:
+            buf = BytesIO()
+            with GzipFile(fileobj=buf, mode="w") as gz:
+                # 'data' was produced by json.dumps(),
+                # whose default encoding is utf-8.
+                gz.write(cast(str, data).encode("utf-8"))
+            data = buf.getvalue()
+            headers["Content-Encoding"] = "gzip"
+        except Exception as exc:
+            log.warning("failed to gzip request body, sending uncompressed: %s", exc)
 
     res = (session or _get_session()).post(
         url, data=data, headers=headers, timeout=timeout

posthog/test/test_request.py

@@ -1,5 +1,6 @@
 import json
 import unittest
+import zlib
 from datetime import date, datetime
 from unittest import mock
 
@@ -179,6 +180,31 @@ def test_post_sends_bytes_payload_with_gzip(self):
         self.assertIsInstance(data, bytes)
         self.assertEqual(headers["Content-Encoding"], "gzip")
 
+    def test_post_falls_back_to_uncompressed_payload_when_gzip_fails(self):
+        for compression_error in [OSError("boom"), zlib.error("boom")]:
+            with self.subTest(compression_error=type(compression_error)):
+                mock_response = requests.Response()
+                mock_response.status_code = 200
+                mock_session = mock.MagicMock()
+                mock_session.post.return_value = mock_response
+
+                with mock.patch.object(
+                    request_module, "GzipFile", side_effect=compression_error
+                ):
+                    request_module.post(
+                        TEST_API_KEY,
+                        host="https://test.posthog.com",
+                        path="/batch/",
+                        gzip=True,
+                        session=mock_session,
+                        batch=[],
+                    )
+
+                data = mock_session.post.call_args.kwargs["data"]
+                headers = mock_session.post.call_args.kwargs["headers"]
+                self.assertIsInstance(data, str)
+                self.assertNotIn("Content-Encoding", headers)
+
     def test_datetime_serialization(self):
         data = {"created": datetime(2012, 3, 4, 5, 6, 7, 891011)}
         result = json.dumps(data, cls=DatetimeSerializer)