writing tests much fun

Author: sl0thentr0py

sentry_sdk/monitor.py

@@ -20,9 +20,9 @@ class Monitor(object):
     name = "sentry.monitor"
 
     def __init__(self, transport, interval=10):
-        # type: (sentry_sdk.transport.Transport, int) -> None
+        # type: (sentry_sdk.transport.Transport, float) -> None
         self.transport = transport  # type: sentry_sdk.transport.Transport
-        self.interval = interval  # type: int
+        self.interval = interval  # type: float
 
         self._healthy = True
         self._downsample_factor = 1  # type: int

tests/test_monitor.py

@@ -0,0 +1,88 @@
+import random
+from time import sleep
+
+from sentry_sdk import Hub, start_transaction
+from sentry_sdk.transport import Transport
+
+
+class HealthyTestTransport(Transport):
+    def _send_event(self, event):
+        pass
+
+    def _send_envelope(self, envelope):
+        pass
+
+    def is_worker_full(self):
+        return False
+
+
+class UnhealthyTestTransport(HealthyTestTransport):
+    def is_worker_full(self):
+        return True
+
+
+def test_no_monitor_if_disabled(sentry_init):
+    sentry_init(transport=HealthyTestTransport())
+    assert Hub.current.client.monitor is None
+
+
+def test_monitor_if_enabled(sentry_init):
+    sentry_init(
+        transport=HealthyTestTransport(),
+        _experiments={"enable_backpressure_handling": True},
+    )
+
+    monitor = Hub.current.client.monitor
+    assert monitor is not None
+    assert monitor._thread is None
+
+    assert monitor.is_healthy() is True
+    assert monitor.downsample_factor() == 1
+    assert monitor._thread is not None
+    assert monitor._thread.name == "sentry.monitor"
+
+
+def test_monitor_unhealthy(sentry_init):
+    sentry_init(
+        transport=UnhealthyTestTransport(),
+        _experiments={"enable_backpressure_handling": True},
+    )
+
+    monitor = Hub.current.client.monitor
+    monitor.interval = 0.1
+
+    assert monitor.is_healthy() is True
+    sleep(0.1)  # wait for monitor to run
+    assert monitor.is_healthy() is False
+    assert monitor.downsample_factor() == 2
+    sleep(0.1)  # wait for monitor to run
+    assert monitor.downsample_factor() == 4
+
+
+def test_transaction_uses_downsampled_rate(
+    sentry_init, capture_client_reports, monkeypatch
+):
+    sentry_init(
+        traces_sample_rate=1.0,
+        transport=UnhealthyTestTransport(),
+        _experiments={"enable_backpressure_handling": True},
+    )
+
+    reports = capture_client_reports()
+
+    monitor = Hub.current.client.monitor
+    monitor.interval = 0.1
+
+    # make sure rng doesn't sample
+    monkeypatch.setattr(random, "random", lambda: 0.9)
+
+    assert monitor.is_healthy() is True
+    sleep(0.1)  # wait for monitor to run
+    assert monitor.is_healthy() is False
+    assert monitor.downsample_factor() == 2
+
+    with start_transaction(name="foobar") as transaction:
+        assert transaction.sampled is False
+        assert transaction.sample_rate == 0.5
+
+    assert reports == [("backpressure", "transaction")]