[RAI-25151]: Fix polling duration in poll_with_specified_overhead function (#151)

* Fix polling duration calculation in poll_with_specified_overhead function

* add more tests

* fix test

* move decorator to the specific test

* fix test

Author: meruyert93

.github/actions/test/action.yml

@@ -61,5 +61,5 @@ runs:
         CUSTOM_HEADERS: ${{ inputs.custom_headers }}
       run: |
         mkdir -p ~/.rai
-        python -m unittest
+        python -m unittest -v
       shell: bash

railib/api.py

@@ -331,27 +331,32 @@ def poll_with_specified_overhead(
     max_tries: int = None,
     max_delay: int = 120,
 ):
+    if overhead_rate < 0:
+        raise ValueError("overhead_rate must be non-negative")
+
     if start_time is None:
         start_time = time.time()
+    
     tries = 0
     max_time = time.time() + timeout if timeout else None
 
     while True:
         if f():
             break
 
+        current_time = time.time()
+        
         if max_tries is not None and tries >= max_tries:
             raise Exception(f'max tries {max_tries} exhausted')
 
-        if max_time is not None and time.time() >= max_time:
+        if max_time is not None and current_time >= max_time:
             raise Exception(f'timed out after {timeout} seconds')
 
+        duration = (current_time - start_time) * overhead_rate
+        duration = min(duration, max_delay)
+        
+        time.sleep(duration) 
         tries += 1
-        duration = min((time.time() - start_time) * overhead_rate, max_delay)
-        if tries == 1:
-            time.sleep(0.5)
-        else:
-            time.sleep(duration)
 
 
 def is_engine_term_state(state: str) -> bool:

test/test_unit.py

@@ -1,4 +1,5 @@
 import socket
+import time
 import unittest
 from unittest.mock import patch, MagicMock
 from urllib.error import URLError
@@ -27,6 +28,48 @@ def test_validation(self):
         api.poll_with_specified_overhead(lambda: True, overhead_rate=0.1, max_tries=1)
         api.poll_with_specified_overhead(lambda: True, overhead_rate=0.1, timeout=1, max_tries=1)
 
+    @patch('time.sleep', return_value=None)
+    @patch('time.time')
+    def test_initial_delay(self, mock_time, mock_sleep):
+        start_time = 100  # Fixed start time
+        increment_time = 0.0001
+        mock_time.side_effect = [start_time, start_time + increment_time]  # Simulate time progression
+
+        try:
+            api.poll_with_specified_overhead(lambda: False, overhead_rate=0.1, max_tries=2)
+        except Exception as e:
+            pass  # Ignore the exception for this test
+
+        expected_sleep_time = (start_time + increment_time - start_time) * 0.1
+        mock_sleep.assert_called_with(expected_sleep_time)
+    
+    def test_max_delay_cap(self):
+        with patch('time.sleep') as mock_sleep:
+            try:
+                api.poll_with_specified_overhead(lambda: False, overhead_rate=1, max_tries=2, start_time=time.time() - 200)
+            except Exception:
+                pass
+            # Ensure that the maximum delay of 120 seconds is not exceeded
+            mock_sleep.assert_called_with(120)
+
+    def test_polling_success(self):
+        with patch('time.sleep', return_value=None) as mock_sleep:
+            api.poll_with_specified_overhead(lambda: True, overhead_rate=0.1)
+            mock_sleep.assert_not_called()
+
+    def test_negative_overhead_rate(self):
+        with self.assertRaises(ValueError):
+            api.poll_with_specified_overhead(lambda: True, overhead_rate=-0.1)
+
+    def test_realistic_scenario(self):
+        responses = [False, False, True]
+        def side_effect():
+            return responses.pop(0)
+
+        with patch('time.sleep') as mock_sleep:
+            api.poll_with_specified_overhead(side_effect, overhead_rate=0.1, max_tries=3)
+            # Ensure that `time.sleep` was called twice (for two false returns)
+            self.assertEqual(mock_sleep.call_count, 2)
 
 @patch('railib.rest.urlopen')
 class TestURLOpenWithRetry(unittest.TestCase):