restructure and test, pure python and rust transport both _work_

tests/test_tracker.py

@@ -10,17 +10,19 @@ from cht.stream.tracker import RecordingTracker
 
 
 class TestRecordingTracker:
-    def test_initial_duration_is_zero(self, tmp_path):
-        tracker = RecordingTracker(tmp_path / "rec.ts")
+    def test_initial_duration_is_zero(self):
+        tracker = RecordingTracker(get_segments=lambda: [])
         assert tracker.duration == 0.0
 
     def test_callback_called_on_update(self, tmp_path):
-        rec = tmp_path / "rec.ts"
-        rec.write_bytes(b"\x00" * 100_000)
+        seg = tmp_path / "rec.mp4"
+        seg.write_bytes(b"\x00" * 100_000)
 
         cb = MagicMock()
-        tracker = RecordingTracker(rec, on_duration_update=cb)
-
+        tracker = RecordingTracker(
+            get_segments=lambda: [seg],
+            on_duration_update=cb,
+        )
         with patch.object(tracker, "_probe_duration", return_value=10.0):
             tracker.start()
             time.sleep(3)
@@ -29,10 +31,44 @@ class TestRecordingTracker:
         cb.assert_called()
         assert cb.call_args[0][0] > 0
 
-    def test_no_callback_if_file_missing(self, tmp_path):
+    def test_no_callback_if_no_segments(self):
         cb = MagicMock()
-        tracker = RecordingTracker(tmp_path / "nonexistent.ts", on_duration_update=cb)
+        tracker = RecordingTracker(get_segments=lambda: [], on_duration_update=cb)
         tracker.start()
         time.sleep(3)
         tracker.stop()
         cb.assert_not_called()
+
+    def test_no_callback_if_file_missing(self, tmp_path):
+        cb = MagicMock()
+        tracker = RecordingTracker(
+            get_segments=lambda: [tmp_path / "nonexistent.mp4"],
+            on_duration_update=cb,
+        )
+        tracker.start()
+        time.sleep(3)
+        tracker.stop()
+        cb.assert_not_called()
+
+    def test_duration_only_increases(self, tmp_path):
+        seg = tmp_path / "rec.mp4"
+        seg.write_bytes(b"\x00" * 100_000)
+        durations = []
+
+        def on_update(d):
+            durations.append(d)
+
+        probe_values = iter([5.0, 3.0, 7.0])  # 3.0 is a regression — should be ignored
+
+        tracker = RecordingTracker(
+            get_segments=lambda: [seg],
+            on_duration_update=on_update,
+        )
+        with patch.object(tracker, "_probe_duration", side_effect=probe_values):
+            tracker.start()
+            time.sleep(7)
+            tracker.stop()
+
+        # Duration should never go backwards
+        for i in range(1, len(durations)):
+            assert durations[i] >= durations[i - 1], "Duration regressed"