Fix off by one errors, add tests and comment

tests/test_pipeline.py

@@ -1,6 +1,9 @@
 import asyncio
 import unittest
+from unittest.mock import Mock
+
 from dailyai.pipeline.aggregators import SentenceAggregator, StatelessTextTransformer
+from dailyai.pipeline.frame_processor import FrameProcessor
 from dailyai.pipeline.frames import EndFrame, TextFrame
 
 from dailyai.pipeline.pipeline import Pipeline
@@ -57,3 +60,52 @@ class TestDailyPipeline(unittest.IsolatedAsyncioTestCase):
             TextFrame(" "),
         )
         self.assertIsInstance(await outgoing_queue.get(), EndFrame)
+
+
+class TestLogFrame(unittest.TestCase):
+    class MockProcessor(FrameProcessor):
+        def __init__(self, name):
+            self.name = name
+
+        def __str__(self):
+            return self.name
+
+    def setUp(self):
+        self.processor1 = self.MockProcessor('processor1')
+        self.processor2 = self.MockProcessor('processor2')
+        self.pipeline = Pipeline(
+            processors=[self.processor1, self.processor2])
+        self.pipeline._name = 'MyClass'
+        self.pipeline._logger = Mock()
+
+    def test_log_frame_from_source(self):
+        frame = Mock(__class__=Mock(__name__='MyFrame'))
+        self.pipeline._log_frame(frame, depth=1)
+        self.pipeline._logger.debug.assert_called_once_with(
+            'MyClass  source -> MyFrame -> processor1')
+
+    def test_log_frame_to_sink(self):
+        frame = Mock(__class__=Mock(__name__='MyFrame'))
+        self.pipeline._log_frame(frame, depth=3)
+        self.pipeline._logger.debug.assert_called_once_with(
+            'MyClass      processor2 -> MyFrame -> sink')
+
+    def test_log_frame_repeated_log(self):
+        frame = Mock(__class__=Mock(__name__='MyFrame'))
+        self.pipeline._log_frame(frame, depth=2)
+        self.pipeline._logger.debug.assert_called_once_with(
+            'MyClass    processor1 -> MyFrame -> processor2')
+        self.pipeline._log_frame(frame, depth=2)
+        self.pipeline._logger.debug.assert_called_with('MyClass    ... repeated')
+
+    def test_log_frame_reset_repeated_log(self):
+        frame1 = Mock(__class__=Mock(__name__='MyFrame1'))
+        frame2 = Mock(__class__=Mock(__name__='MyFrame2'))
+        self.pipeline._log_frame(frame1, depth=2)
+        self.pipeline._logger.debug.assert_called_once_with(
+            'MyClass    processor1 -> MyFrame1 -> processor2')
+        self.pipeline._log_frame(frame1, depth=2)
+        self.pipeline._logger.debug.assert_called_with('MyClass    ... repeated')
+        self.pipeline._log_frame(frame2, depth=2)
+        self.pipeline._logger.debug.assert_called_with(
+            'MyClass    processor1 -> MyFrame2 -> processor2')