Make endless long-polling

tests/test_utils/test_backoff.py

@@ -0,0 +1,76 @@
+import pytest
+
+from aiogram.utils.backoff import Backoff, BackoffConfig
+
+BACKOFF_CONFIG = BackoffConfig(min_delay=0.1, max_delay=1.0, factor=2.0, jitter=0.0)
+
+
+class TestBackoffConfig:
+    @pytest.mark.parametrize(
+        "kwargs",
+        [
+            dict(min_delay=1.0, max_delay=1.0, factor=2.0, jitter=0.1),  # equals min and max
+            dict(min_delay=1.0, max_delay=1.0, factor=1.0, jitter=0.1),  # factor == 1
+            dict(min_delay=1.0, max_delay=2.0, factor=0.5, jitter=0.1),  # factor < 1
+            dict(min_delay=2.0, max_delay=1.0, factor=2.0, jitter=0.1),  # min > max
+        ],
+    )
+    def test_incorrect_post_init(self, kwargs):
+        with pytest.raises(ValueError):
+            BackoffConfig(**kwargs)
+
+    @pytest.mark.parametrize(
+        "kwargs",
+        [dict(min_delay=1.0, max_delay=2.0, factor=1.2, jitter=0.1)],
+    )
+    def test_correct_post_init(self, kwargs):
+        assert BackoffConfig(**kwargs)
+
+
+class TestBackoff:
+    def test_aliases(self):
+        backoff = Backoff(config=BACKOFF_CONFIG)
+        assert backoff.min_delay == BACKOFF_CONFIG.min_delay
+        assert backoff.max_delay == BACKOFF_CONFIG.max_delay
+        assert backoff.factor == BACKOFF_CONFIG.factor
+        assert backoff.jitter == BACKOFF_CONFIG.jitter
+
+    def test_calculation(self):
+        backoff = Backoff(config=BACKOFF_CONFIG)
+        index = 0
+
+        iterable = iter(backoff)
+        assert iterable == backoff
+
+        assert backoff.current_delay == 0.0
+        assert backoff.next_delay == 0.1
+
+        while (val := next(backoff)) < 1:
+            index += 1
+            assert val in {0.1, 0.2, 0.4, 0.8}
+
+        assert next(backoff) == 1
+        assert next(backoff) == 1
+        assert index == 4
+
+        assert backoff.current_delay == 1
+        assert backoff.next_delay == 1
+        assert backoff.counter == 7  # 4+1 in while loop + 2 after loop
+
+        assert str(backoff) == "Backoff(tryings=7, current_delay=1.0, next_delay=1.0)"
+
+        backoff.reset()
+        assert backoff.current_delay == 0.0
+        assert backoff.next_delay == 0.1
+        assert backoff.counter == 0
+
+    def test_sleep(self):
+        backoff = Backoff(config=BACKOFF_CONFIG)
+        backoff.sleep()
+        assert backoff.counter == 1
+
+    @pytest.mark.asyncio
+    async def test_asleep(self):
+        backoff = Backoff(config=BACKOFF_CONFIG)
+        await backoff.asleep()
+        assert backoff.counter == 1