fix rate limiter

openaq/client.py

@@ -7,6 +7,7 @@
 from __future__ import annotations
 
 import logging
+import math
 import os
 import platform
 import re
@@ -248,7 +249,9 @@ def base_url(self) -> str:
     @property
     def _rate_limit_reset_seconds(self) -> int:
         """Seconds remaining until the rate limit window resets."""
-        return int((self._rate_limit_reset_datetime - datetime.now()).total_seconds())
+        return math.ceil(
+            (self._rate_limit_reset_datetime - datetime.now()).total_seconds()
+        )
 
     def _is_rate_limited(self) -> bool:
         """Returns True if the rate limit is exhausted and the reset time has not yet passed."""
@@ -311,7 +314,7 @@ def _wait_for_rate_limit_reset(self) -> None:
         Returns immediately if the reset time has already passed.
         """
         wait_seconds = self._rate_limit_reset_seconds
-        if wait_seconds <= 0:
+        if wait_seconds <= 1:
             wait_seconds = 1
         logger.info("Rate limit hit. Waiting %s seconds for reset.", wait_seconds)
         time.sleep(wait_seconds)

tests/unit/test_client.py

@@ -1,3 +1,4 @@
+import http
 import os
 import platform
 from datetime import datetime, timedelta
@@ -61,6 +62,15 @@ def test__check_api_key(api_key, expected_exception):
         assert result == api_key
 
 
+def apply_rate_limit_headers(client, *, at, remaining, ttl):
+    msg = http.client.HTTPMessage()
+    msg["x-ratelimit-limit"] = "60"
+    msg["x-ratelimit-remaining"] = str(remaining)
+    msg["x-ratelimit-reset"] = str(ttl)
+    with freeze_time(at):
+        client._set_rate_limit(Headers(msg))
+
+
 @pytest.fixture
 def mock_config_file():
     mock_toml_content = b"""api-key='e7a3a978e3e018e932d666c481ff33b82b7150c6084c0de175755c5cb763a5c5'"""
@@ -480,6 +490,33 @@ def test_raises_value_error_for_base_url_without_netloc(self):
                 _transport=MockTransport(),
             )
 
+    def test_production_replay_20260628(self, setup):
+        apply_rate_limit_headers(
+            self.client, at="2026-06-28 17:55:44.59+00", remaining=1, ttl=11
+        )
+        with freeze_time("2026-06-28 17:55:50.1+00"):
+            self.client._check_rate_limit()
+
+            apply_rate_limit_headers(
+                self.client, at="2026-06-28 17:55:50.1+00", remaining=0, ttl=10
+            )
+
+        with (
+            freeze_time("2026-06-28 17:55:45.1+00"),
+            patch("time.sleep") as mock_sleep,
+        ):
+            self.client._check_rate_limit()
+
+            mock_sleep.assert_called_once()
+            sleep_time = mock_sleep.call_args[0][0]
+
+            assert sleep_time >= 15.0
+
+        with freeze_time("2026-06-28 17:56:01.000000+00"):
+            with patch("time.sleep") as mock_sleep_after_reset:
+                self.client._check_rate_limit()
+                mock_sleep_after_reset.assert_not_called()
+
 
 def test_tomllib_conditional_import():
     if int(platform.python_version_tuple()[1]) >= 11: