editor: Add corner cases for comment_lines.

diff_edit/editor.py

@@ -462,21 +462,37 @@ class Editor:
                 try:
                     index = self.text_widget[self.cursor_y].index("#")
                     self.cursor_x = index + 1
-                except ValueError:
+                except ValueError:  # '#' not in line
                     self.jump_to_end_of_line()
                     self.insert_text("  # ")
         else:
             (start_x, start_y), (end_x, end_y) = self.get_selection_interval()
-            min_indent = min(self._line_indent(y) for y in range(start_y, end_y)
+            if end_x != 0 and not self.cursor_x == len(self.text_widget[end_y]):
+                self.enter()
+                self.cursor_left()
+            if start_x != 0:
+                new_line = (self.text_widget[start_y][:start_x] + "# " +
+                            self.text_widget[start_y][start_x:])
+                self.text_widget[start_y] = new_line
+                self.cursor_x = len(new_line)
+                start_y += 1
+            if end_x != 0:
+                end_y += 1
+            mid_lines = range(start_y, end_y)
+            try:
+                min_indent = min(self._line_indent(y) for y in mid_lines
                                  if self.text_widget[y].strip() != "")
-            if all(self.text_widget[y][min_indent:min_indent+2] == "# " or self.text_widget[y].strip() == ""
+            except ValueError:
-                   for y in range(start_y, end_y)):
+                pass
-                for y in range(start_y, end_y):
+            else:
+                if all(self.text_widget[y][min_indent:min_indent+2] == "# "
+                       or self.text_widget[y].strip() == "" for y in mid_lines):
+                    for y in mid_lines:
                         line = self.text_widget[y]
                         if line.strip() != "":
                             self.text_widget[y] = line[:min_indent] + line[min_indent + 2:]
                 else:
-                for y in range(start_y, end_y):
+                    for y in mid_lines:
                         line = self.text_widget[y]
                         if line.strip() != "":
                             self.text_widget[y] = line[:min_indent] + "# " + line[min_indent:]

tests/editor_test.py

@@ -66,7 +66,7 @@ class EditorTestCase(unittest.TestCase):
 
     def _assert_changes(self, changes):
         for index, change in enumerate(changes):
-            with self.subTest(index=index, change=change):
+            # with self.subTest(index=index, change=change):
             method, expected_text, expected_cursor_position = change
             with contextlib.suppress(IndexError):
                 method()
@@ -166,12 +166,16 @@ class EditorTestCase(unittest.TestCase):
                               (self.editor.tab_align, " a\n b", (1, 1))])
 
     def test_comment_lines(self):
+        # from scratch
         self._set_editor("", (0, 0))
         self._assert_changes([(self.editor.comment_lines, "# ", (2, 0))])
+        # No selection
         self._set_editor("a", (0, 0))
         self._assert_changes([(self.editor.comment_lines, "a  # ", (5, 0))])
+        # Comment when comment exists
         self.editor.jump_to_start_of_line()
         self._assert_changes([(self.editor.comment_lines, "a  # ", (4, 0))])
+        # Selection containing blank lines
         text = "  a\n\n b\n"
         self._set_editor(text, (0, 0))
         self.editor.set_mark()
@@ -180,11 +184,28 @@ class EditorTestCase(unittest.TestCase):
         self.editor.cursor_down()
         self._assert_changes([(self.editor.comment_lines, " #  a\n\n # b\n", (0, 3))])
         self.assertEqual(self.editor.mark, None)
+        # Undo comments in selection
         self.editor.set_mark()
         self.editor.cursor_up()
         self.editor.cursor_up()
         self.editor.cursor_up()
         self._assert_changes([(self.editor.comment_lines, text, (0, 0))])
+        # Selection on one line, in middle
+        self._set_editor("abc", (1, 0))
+        self.editor.set_mark()
+        self.editor.cursor_right()
+        self._assert_changes([(self.editor.comment_lines, "a# b\nc", (4, 0))])
+        # Selection on one line, on right
+        self._set_editor("ab", (1, 0))
+        self.editor.set_mark()
+        self.editor.cursor_right()
+        self._assert_changes([(self.editor.comment_lines, "a# b", (4, 0))])
+        # Multi-line selection, starting middle, ending middle. Trailing unselected line
+        self._set_editor("abc\ndef\nghi\njkl", (2, 0))
+        self.editor.set_mark()
+        self.editor.cursor_down()
+        self.editor.cursor_down()
+        self._assert_changes([(self.editor.comment_lines, "ab# c\n# def\n# gh\ni\njkl", (4, 2))])
 
 
 if __name__ == "__main__":