Editor: Fix file completions when requesting them to the right of a dot

Also add a test for that case.

Author: ccordoba12

spyder/plugins/editor/widgets/base.py

@@ -963,22 +963,37 @@ def insert_completion(self, completion, completion_position):
                     if current_text == '.':
                         is_auto_completion_character = True
                 else:
-                    if current_text in self.auto_completion_characters:
+                    if (
+                        kind != CompletionItemKind.FILE and
+                        current_text in self.auto_completion_characters
+                    ):
                         is_auto_completion_character = True
 
                 # Adjustments for file completions
                 if kind == CompletionItemKind.FILE:
-                    # This is necessary to inseert file completions when
-                    # requesting them next to a colon
                     if current_text in ['"', "'"]:
+                        # This is necessary to insert file completions when
+                        # requesting them next to a colon
                         current_text = ''
                         start_position += 1
-
-                    # And this insert completions for files or directories that
-                    # start with a dot
-                    if current_text in ['".', "'."]:
+                    elif current_text in ['".', "'."]:
+                        # This inserts completions for files or directories
+                        # that start with a dot
                         current_text = '.'
                         start_position += 1
+                    elif current_text == '.':
+                        # This is needed if users are asking for file
+                        # completions to the right of a dot
+                        cursor_1 = self.textCursor()
+                        cursor_1.movePosition(
+                            QTextCursor.PreviousCharacter,
+                            QTextCursor.MoveAnchor,
+                            2
+                        )
+                        cursor_1.select(QTextCursor.WordUnderCursor)
+                        current_text = str(cursor_1.selectedText())
+                        start_position = cursor_1.selectionStart()
+                        end_position = start_position + len(current_text) + 1
 
                 if not is_auto_completion_character:
                     # Check if the completion position is in the expected range

spyder/plugins/editor/widgets/tests/test_introspection.py

@@ -1223,7 +1223,8 @@ def test_dot_completions(completions_codeeditor, qtbot):
 
 @pytest.mark.slow
 @pytest.mark.order(1)
-@pytest.mark.parametrize("filename", ['000_test.txt', '.hidden', 'any_file'])
+@pytest.mark.parametrize(
+    "filename", ['000_test.txt', '.hidden', 'any_file.txt', 'abc.py'])
 def test_file_completions(filename, mock_completions_codeeditor, qtbot):
     """
     Test that completions for files are handled as expected.
@@ -1235,10 +1236,14 @@ def test_file_completions(filename, mock_completions_codeeditor, qtbot):
 
     # Set text to complete and move cursor to the position we want to ask for
     # completions.
-    if filename == 'any_file':
+    if filename == 'any_file.txt':
         # This checks if we're able to introduce file completions as expected
         # for any file when requesting them inside a string.
         qtbot.keyClicks(code_editor, "''")
+    elif filename == 'abc.py':
+        # This checks that we can insert file completions correctly after a
+        # dot
+        qtbot.keyClicks(code_editor, "'abc.'")
     else:
         qtbot.keyClicks(code_editor, f"'{filename[0]}'")
     code_editor.moveCursor(QTextCursor.PreviousCharacter)