test: add TestJSONFE with mocks

test/test_feature_extractors.py

@@ -5,6 +5,8 @@ import pytest
 import pipeline.feature_extractors as extractors
 
 from pipeline.utils import Source, SourceMedia # technically makes this an integration test, but...
+from unittest.mock import patch, mock_open
+
 class TestSource():
     """Provide utils.Source for testing"""
     def one_colour_silent_audio(self):
@@ -19,6 +21,19 @@ class TestSourceMedia():
         """Provide a source with a silent mono-colour video"""
         return SourceMedia(sources=[TestSource().one_colour_silent_audio()])
 
+class MockReadJSON():
+    """Mock read_json"""
+    def mock_read_json_from_file(self, *args, **kwargs):
+        """Mock _read_json_from_file()"""
+        rJSON = [{"interval": {"start": 0.0, "duration": 1.0},
+                 "source": {"source": "test_video_red_silentaudio.mp4",
+                            "path": "test_video_red_silentaudio.mp4",
+                            "provider": "mock"},
+                 "feature_extractor": "MockFeatureExtractor",
+                 "score": 0.5
+                 }]
+        return rJSON
+
 class TestLaughterFeatureExtractor(unittest.TestCase):
     def _mock_laughdetect_callout(self, *args, **kwargs):
         """Mock _laughdetect callout
@@ -183,3 +198,33 @@ class TestVideoActivityFeatureExtractor(unittest.TestCase):
 
     # TODO: add sample video with activity to test _activitydetect()
 
+class TestJSONFeatureExtractor(unittest.TestCase):
+    """Test JSONFeatureExtractor"""
+    def test_init(self):
+        video_source = TestSourceMedia().one_colour_silent_audio()
+        test_extractor = extractors.JSONFeatureExtractor(input_files=video_source)
+        self.assertTrue(test_extractor)
+
+    def test_init_noinput(self):
+        """test init - no input files"""
+        with self.assertRaises(ValueError):
+            test_extractor = extractors.JSONFeatureExtractor()
+
+    def test_extract(self):
+        """Test extract with basic input file runs with no errors"""
+        video_source = TestSourceMedia().one_colour_silent_audio()
+        test_extractor = extractors.JSONFeatureExtractor(input_files=video_source)
+        # mock _read_json_from_file
+        test_extractor._read_json_from_file = MockReadJSON().mock_read_json_from_file
+        test_extractor.setup()
+        test_extractor.run()
+        test_extractor.teardown()
+        self.assertTrue(test_extractor.features)
+
+    def test_read_json_from_file(self):
+        """Test _read_json_from_file"""
+        video_source = TestSourceMedia().one_colour_silent_audio()
+        test_extractor = extractors.JSONFeatureExtractor(input_files=video_source)
+        m = unittest.mock.mock_open(read_data='[{"foo": "bar"}]')
+        with unittest.mock.patch("builtins.open", m):
+            test_extractor._read_json_from_file("foo.json")