1. Converting 'empty_arrows_keys.js' into selenium based test

2. Moved "delete_cell" method to utils.py and modified references to use it from there
3. added a generalized method "trigger_keystrokes" to send keystrokes to browser

Author: arovitn

notebook/tests/notebook/empty_arrow_keys.js

@@ -3,11 +3,6 @@ def cell_is_deletable(nb, index):
     JS = 'return Jupyter.notebook.get_cell({}).is_deletable();'.format(index)
     return nb.browser.execute_script(JS)
 
-def delete_cell(notebook, index):
-    notebook.focus_cell(index)
-    notebook.to_command_mode
-    notebook.current_cell.send_keys('dd')
-
 def test_delete_cells(notebook):
     a = 'print("a")'
     b = 'print("b")'
@@ -30,22 +25,22 @@ def test_delete_cells(notebook):
     assert cell_is_deletable(notebook, 2)
 
     # Try to delete cell a (should not be deleted)
-    delete_cell(notebook, 0)
+    notebook.delete_cell(0)
     assert notebook.get_cells_contents() == [a, b, c]
 
     # Try to delete cell b (should succeed)
-    delete_cell(notebook, 1)
+    notebook.delete_cell(1)
     assert notebook.get_cells_contents() == [a, c]
 
     # Try to delete cell c (should succeed)
-    delete_cell(notebook, 1)
+    notebook.delete_cell(1)
     assert notebook.get_cells_contents() == [a]
 
     # Change the deletable state of cell a
     notebook.set_cell_metadata(0, 'deletable', 'true')
 
     # Try to delete cell a (should succeed)
-    delete_cell(notebook, 0)
+    notebook.delete_cell(0)
     assert len(notebook.cells) == 1 # it contains an empty cell
 
     # Make sure copied cells are deletable

notebook/tests/selenium/test_deletecell.py

@@ -0,0 +1,13 @@
+# selenium test version for 'empty_arrow_keys.js'
+
+
+def remove_cells(notebook):
+    for i in notebook.cells:
+        notebook.delete_cell(notebook.index(i))
+    return True
+
+def test_empty_arrows_keys(notebook):
+    # delete all the cells
+    notebook.trigger_keydown('up')
+    notebook.trigger_keydown('down')
+    assert remove_cells(notebook);

notebook/tests/selenium/test_empty_arrows_keys.py

@@ -184,6 +184,11 @@ def add_cell(self, index=-1, cell_type="code", content=""):
         if cell_type != 'code':
             self.convert_cell_type(index=new_index, cell_type=cell_type)
 
+    def delete_cell(self, index):
+        self.focus_cell(index)
+        self.to_command_mode
+        self.current_cell.send_keys('dd')
+
     def add_markdown_cell(self, index=-1, content="", render=True):
         self.add_cell(index, cell_type="markdown")
         self.edit_cell(index=index, content=content, render=render)
@@ -203,6 +208,9 @@ def run_all(self):
         for cell in self:
             self.execute_cell(cell)
 
+    def trigger_keydown(self, keys):
+        trigger_keystrokes(self.body, keys)
+
     @classmethod
     def new_notebook(cls, browser, kernel_name='kernel-python3'):
         with new_window(browser, selector=".cell"):
@@ -251,10 +259,27 @@ def new_window(browser, selector=None):
 
 def shift(browser, k):
     """Send key combination Shift+(k)"""
-    ActionChains(browser)\
-        .key_down(Keys.SHIFT).send_keys(k).key_up(Keys.SHIFT).perform()
+    trigger_keystrokes(browser, "shift-%s"%k)
 
 def ctrl(browser, k):
     """Send key combination Ctrl+(k)"""
-    ActionChains(browser)\
-        .key_down(Keys.CONTROL).send_keys(k).key_up(Keys.CONTROL).perform()
+    trigger_keystrokes(browser, "control-%s"%k)
+
+def trigger_keystrokes(browser, *keys):
+    """ Send the keys in sequence to the browser.
+    Handles following key combinations
+    1. with modifiers eg. 'control-alt-a', 'shift-c'
+    2. just modifiers eg. 'alt', 'esc'
+    3. non-modifiers eg. 'abc'
+    Modifiers : http://seleniumhq.github.io/selenium/docs/api/py/webdriver/selenium.webdriver.common.keys.html
+    """
+    for each_key_combination in keys:
+        keys = each_key_combination.split('-')
+        if len(keys) > 1:  # key has modifiers eg. control, alt, shift
+            modifiers_keys = list(map(lambda x:getattr(Keys, x.upper()), keys[:-1]))
+            ac = ActionChains(browser)
+            for i in modifiers_keys: ac = ac.key_down(i)
+            ac.send_keys(keys[-1])
+            for i in modifiers_keys[::-1]: ac = ac.key_up(i)
+        else:              # single key stroke. Check if modifier eg. "up"
+            browser.send_keys(getattr(Keys, keys[0].upper(), keys[0]))