add more tests

src/ui/bigtext/testlogfilemodel.py

@@ -111,7 +111,7 @@ class TestLogFileModel(unittest.TestCase):
 
     def test_scroll_with_float(self):
         """
-        If lines to lines to return is a float, then the value is rounded up.
+        If lines to return is a float, then the value is rounded up.
         Floats mean that the text area is such that a line is partially visible.
         """
         text = "0___\n1___\n2___\n3___\n4___\n5___"
@@ -138,6 +138,52 @@ class TestLogFileModel(unittest.TestCase):
         line_str = [l.line() for l in lines]
         self.assertEqual(expected_lines, line_str)
 
+    def test_scroll_up_at_beginning_of_range(self):
+        """
+        Scrolling up at beginning of a range.
+        Current position is at the beginning of the range.
+        :return:
+        """
+        text = "0___\n1___\n2___\n3___\n4___\n5___"
+        self.write_str(text)
+        expected_lines = ["2___\n", "3___\n"]
+
+        lines = self.model.data(10, -2, 2, 10, -1)
+
+        line_str = [l.line() for l in lines]
+        self.assertEqual(expected_lines, line_str)
+
+    def test_scroll_up_in_middle_of_range(self):
+        """
+        Scrolling up at beginning of a range.
+        Current position is one line after the beginning of the range
+        :return:
+        """
+        text = "0___\n1___\n2___\n3___\n4___\n5___"
+        self.write_str(text)
+        expected_lines = ["2___\n", "3___\n"]
+
+        lines = self.model.data(15, -2, 2, 10, -1)
+
+        line_str = [l.line() for l in lines]
+        self.assertEqual(expected_lines, line_str)
+
+    def test_scroll_down_behind_end_of_range(self):
+        """
+        Scrolling down_behind the end of the range.
+        The last lines of the range are returned.
+        In this example the range is lines 2 and 3.
+        :return:
+        """
+        text = "0___\n1___\n2___\n3___\n4___\n5___"
+        self.write_str(text)
+        expected_lines = ["2___\n", "3___\n"]
+
+        lines = self.model.data(15, -2, 2, 10, 20)
+
+        line_str = [l.line() for l in lines]
+        self.assertEqual(expected_lines, line_str)
+
     def test_read_word_at_middle_of_line(self):
         text = "0___\nlorem ipsum dolor sit amet\n2___"
         self.write_str(text)