fix(launch-darkly-importer): Seconds X-Ratelimit-Reset timestamps are expected for rate limited requests (#5536)

Author: khvn26

api/integrations/launch_darkly/client.py

@@ -38,11 +38,19 @@ def _get_retry_after(exc: RequestException) -> float | None:
             (response := exc.response) is not None
         ) and response.status_code == HTTP_429_TOO_MANY_REQUESTS:
             headers = response.headers
+            # Clients must wait at least `Retry-After` seconds
+            # before making additional calls to the API
             if retry_after := headers.get("Retry-After"):
                 return float(retry_after)
+            # The time at which the current rate limit window resets in epoch milliseconds
             if ratelimit_reset := headers.get("X-Ratelimit-Reset"):
-                return float(ratelimit_reset) - timezone_now().timestamp()
-            # We have no retry information, use a default backoff time
+                timestamp = int(ratelimit_reset) / 1000
+                # Use default backoff time if the timestamp is in the past.
+                return (
+                    max(timestamp - timezone_now().timestamp(), 0)
+                    or BACKOFF_DEFAULT_RETRY_AFTER_SECONDS
+                )
+            # If no retry information retrieved, use a default backoff time
             # of 10 seconds as per LD documentation.
             return BACKOFF_DEFAULT_RETRY_AFTER_SECONDS
         return None

api/tests/unit/integrations/launch_darkly/test_client.py

@@ -214,7 +214,7 @@ def test_launch_darkly_client__get_flag_tags__return_expected(
 
 @pytest.mark.parametrize(
     "response_headers",
-    [{"Retry-After": "0.1"}, {"X-Ratelimit-Reset": "1672531200.1"}],
+    [{"Retry-After": "0.1"}, {"X-Ratelimit-Reset": "1672531200100"}],
 )
 @pytest.mark.freeze_time("2023-01-01T00:00:00Z")
 def test_launch_darkly_client__rate_limit__expected_backoff(
@@ -252,7 +252,7 @@ def test_launch_darkly_client__rate_limit__expected_backoff(
 
 @pytest.mark.parametrize(
     "response_headers",
-    [{"Retry-After": "0.1"}, {"X-Ratelimit-Reset": "1672531200.1"}],
+    [{"Retry-After": "0.1"}, {"X-Ratelimit-Reset": "1672531200100"}],
 )
 @pytest.mark.freeze_time("2023-01-01T00:00:00Z")
 def test_launch_darkly_client__rate_limit_max_retries__raises_expected(