Add tests for chunk_minmax

tests/test_model/test_handling_data.py

@@ -827,3 +827,30 @@ class TestDownsample(TestCase):
         # This ensures that we don't do two unneeded copy operations.
         self.assertIs(times, self.times)
         self.assertIs(data, self.data)
+
+
+class TestChunkMinmax(TestCase):
+    def setUp(self):
+        self.times = np.arange(1000)
+        self.data = np.arange(1000)
+
+    def test_data_size_is_multiple_of_requested_points(self):
+        req_points = 100
+        times, data = chunk_minmax(self.times, self.data, req_points)
+        self.assertEqual(times.size, req_points)
+        self.assertEqual(data.size, req_points)
+
+    @patch('sohstationviewer.model.handling_data.downsample', wraps=downsample)
+    def test_data_size_is_not_multiple_of_requested_points(self,
+                                                           mock_downsample):
+        req_points = 102
+        chunk_minmax(self.times, self.data, req_points)
+        self.assertTrue(mock_downsample.called)
+
+    def test_requested_points_too_small(self):
+        small_req_points_list = [0, 1]
+        for req_points in small_req_points_list:
+            with self.subTest(f'test_requested_points_is_{req_points}'):
+                times, data = chunk_minmax(self.times, self.data, req_points)
+                self.assertEqual(times.size, 0)
+                self.assertEqual(data.size, 0)