def test_delete():
"""
To test command_delete method
:return: Test result
"""
print("Testing delete......")
test_case = Editor()
# case 1 : delete a line of text in the editor
test_case.command_read('text.txt')
origin_text = test_case.list[0]
test_case.command_delete('0')
final_text = test_case.list[0]
assert origin_text != final_text, "Delete method does not work!"
def test_delete_fail():
# case 2 : index out of range
test_case = Editor()
test_case.command_delete(100)