Merge pull request #11734 from Carreau/autoformat-black

Autoformat with black

docs/source/whatsnew/pr/autoformatting.rst

@@ -0,0 +1,24 b''
+Code autoformatting
+===================
+
+The IPython terminal can now auto format your code just before entering a new
+line or executing a command. To do so use the
+``--TerminalInteractiveShell.autoformatter`` option and set it to ``'black'``;
+if black is installed IPython will use black to format your code when possible. 
+
+IPython cannot always properly format your code; in particular it will
+auto formatting with *black* will only work if:
+
+   - Your code does not contains magics or special python syntax. 
+
+   - There is no code after your cursor. 
+
+The Black API is also still in motion; so this may not work with all versions of
+black. 
+
+It should be possible to register custom reformatter, though the API is till in
+flux. 
+
+
+
+

IPython/terminal/interactiveshell.py

@@ -1,570 +1,593 b''
 """IPython terminal interface using prompt_toolkit"""
 
 import os
 import sys
 import warnings
 from warnings import warn
 
 from IPython.core.interactiveshell import InteractiveShell, InteractiveShellABC
 from IPython.utils import io
 from IPython.utils.py3compat import input
 from IPython.utils.terminal import toggle_set_term_title, set_term_title, restore_term_title
 from IPython.utils.process import abbrev_cwd
 from traitlets import (
     Bool, Unicode, Dict, Integer, observe, Instance, Type, default, Enum, Union,
     Any, validate
 )
 
 from prompt_toolkit.enums import DEFAULT_BUFFER, EditingMode
 from prompt_toolkit.filters import (HasFocus, Condition, IsDone)
 from prompt_toolkit.formatted_text import PygmentsTokens
 from prompt_toolkit.history import InMemoryHistory
 from prompt_toolkit.layout.processors import ConditionalProcessor, HighlightMatchingBracketProcessor
 from prompt_toolkit.output import ColorDepth
 from prompt_toolkit.patch_stdout import patch_stdout
 from prompt_toolkit.shortcuts import PromptSession, CompleteStyle, print_formatted_text
 from prompt_toolkit.styles import DynamicStyle, merge_styles
 from prompt_toolkit.styles.pygments import style_from_pygments_cls, style_from_pygments_dict
 
 from pygments.styles import get_style_by_name
 from pygments.style import Style
 from pygments.token import Token
 
 from .debugger import TerminalPdb, Pdb
 from .magics import TerminalMagics
 from .pt_inputhooks import get_inputhook_name_and_func
 from .prompts import Prompts, ClassicPrompts, RichPromptDisplayHook
 from .ptutils import IPythonPTCompleter, IPythonPTLexer
 from .shortcuts import create_ipython_shortcuts
 
 DISPLAY_BANNER_DEPRECATED = object()
 
 
 class _NoStyle(Style): pass
 
 
 
 _style_overrides_light_bg = {
             Token.Prompt: '#0000ff',
             Token.PromptNum: '#0000ee bold',
             Token.OutPrompt: '#cc0000',
             Token.OutPromptNum: '#bb0000 bold',
 }
 
 _style_overrides_linux = {
             Token.Prompt: '#00cc00',
             Token.PromptNum: '#00bb00 bold',
             Token.OutPrompt: '#cc0000',
             Token.OutPromptNum: '#bb0000 bold',
 }
 
 def get_default_editor():
     try:
         return os.environ['EDITOR']
     except KeyError:
         pass
     except UnicodeError:
         warn("$EDITOR environment variable is not pure ASCII. Using platform "
              "default editor.")
 
     if os.name == 'posix':
         return 'vi'  # the only one guaranteed to be there!
     else:
         return 'notepad' # same in Windows!
 
 # conservatively check for tty
 # overridden streams can result in things like:
 # - sys.stdin = None
 # - no isatty method
 for _name in ('stdin', 'stdout', 'stderr'):
     _stream = getattr(sys, _name)
     if not _stream or not hasattr(_stream, 'isatty') or not _stream.isatty():
         _is_tty = False
         break
 else:
     _is_tty = True
 
 
 _use_simple_prompt = ('IPY_TEST_SIMPLE_PROMPT' in os.environ) or (not _is_tty)
 
+def black_reformat_handler(text_before_cursor):
+    import black
+    formatted_text = black.format_str(text_before_cursor, mode=black.FileMode())
+    if not text_before_cursor.endswith('\n') and formatted_text.endswith('\n'):
+       formatted_text = formatted_text[:-1]
+    return formatted_text
+
+
 class TerminalInteractiveShell(InteractiveShell):
     space_for_menu = Integer(6, help='Number of line at the bottom of the screen '
                                      'to reserve for the completion menu'
                             ).tag(config=True)
 
     pt_app = None
     debugger_history = None
 
     simple_prompt = Bool(_use_simple_prompt,
         help="""Use `raw_input` for the REPL, without completion and prompt colors.
 
             Useful when controlling IPython as a subprocess, and piping STDIN/OUT/ERR. Known usage are:
             IPython own testing machinery, and emacs inferior-shell integration through elpy.
 
             This mode default to `True` if the `IPY_TEST_SIMPLE_PROMPT`
             environment variable is set, or the current terminal is not a tty."""
             ).tag(config=True)
 
     @property
     def debugger_cls(self):
         return Pdb if self.simple_prompt else TerminalPdb
 
     confirm_exit = Bool(True,
         help="""
         Set to confirm when you try to exit IPython with an EOF (Control-D
         in Unix, Control-Z/Enter in Windows). By typing 'exit' or 'quit',
         you can force a direct exit without any confirmation.""",
     ).tag(config=True)
 
     editing_mode = Unicode('emacs',
         help="Shortcut style to use at the prompt. 'vi' or 'emacs'.",
     ).tag(config=True)
 
+    autoformatter = Unicode(None,
+        help="Autoformatter to reformat Terminal code. Can be `'black'` or `None`",
+        allow_none=True
+    ).tag(config=True)
+
     mouse_support = Bool(False,
         help="Enable mouse support in the prompt\n(Note: prevents selecting text with the mouse)"
     ).tag(config=True)
 
     # We don't load the list of styles for the help string, because loading
     # Pygments plugins takes time and can cause unexpected errors.
     highlighting_style = Union([Unicode('legacy'), Type(klass=Style)],
         help="""The name or class of a Pygments style to use for syntax
         highlighting. To see available styles, run `pygmentize -L styles`."""
     ).tag(config=True)
 
     @validate('editing_mode')
     def _validate_editing_mode(self, proposal):
         if proposal['value'].lower() == 'vim':
             proposal['value']= 'vi'
         elif proposal['value'].lower() == 'default':
             proposal['value']= 'emacs'
 
         if hasattr(EditingMode, proposal['value'].upper()):
             return proposal['value'].lower()
 
         return self.editing_mode
 
 
     @observe('editing_mode')
     def _editing_mode(self, change):
         u_mode = change.new.upper()
         if self.pt_app:
             self.pt_app.editing_mode = u_mode
 
+    @observe('autoformatter')
+    def _autoformatter_changed(self, change):
+        formatter = change.new
+        if formatter is None:
+            self.reformat_handler = lambda x:x
+        elif formatter == 'black':
+            self.reformat_handler = black_reformat_handler
+        else:
+            raise ValueError
+
     @observe('highlighting_style')
     @observe('colors')
     def _highlighting_style_changed(self, change):
         self.refresh_style()
 
     def refresh_style(self):
         self._style = self._make_style_from_name_or_cls(self.highlighting_style)
 
 
     highlighting_style_overrides = Dict(
         help="Override highlighting format for specific tokens"
     ).tag(config=True)
 
     true_color = Bool(False,
         help=("Use 24bit colors instead of 256 colors in prompt highlighting. "
               "If your terminal supports true color, the following command "
               "should print 'TRUECOLOR' in orange: "
               "printf \"\\x1b[38;2;255;100;0mTRUECOLOR\\x1b[0m\\n\"")
     ).tag(config=True)
 
     editor = Unicode(get_default_editor(),
         help="Set the editor used by IPython (default to $EDITOR/vi/notepad)."
     ).tag(config=True)
 
     prompts_class = Type(Prompts, help='Class used to generate Prompt token for prompt_toolkit').tag(config=True)
 
     prompts = Instance(Prompts)
 
     @default('prompts')
     def _prompts_default(self):
         return self.prompts_class(self)
 
 #    @observe('prompts')
 #    def _(self, change):
 #        self._update_layout()
 
     @default('displayhook_class')
     def _displayhook_class_default(self):
         return RichPromptDisplayHook
 
     term_title = Bool(True,
         help="Automatically set the terminal title"
     ).tag(config=True)
 
     term_title_format = Unicode("IPython: {cwd}",
         help="Customize the terminal title format.  This is a python format string. " +
              "Available substitutions are: {cwd}."
     ).tag(config=True)
 
     display_completions = Enum(('column', 'multicolumn','readlinelike'),
         help= ( "Options for displaying tab completions, 'column', 'multicolumn', and "
                 "'readlinelike'. These options are for `prompt_toolkit`, see "
                 "`prompt_toolkit` documentation for more information."
                 ),
         default_value='multicolumn').tag(config=True)
 
     highlight_matching_brackets = Bool(True,
         help="Highlight matching brackets.",
     ).tag(config=True)
 
     extra_open_editor_shortcuts = Bool(False,
         help="Enable vi (v) or Emacs (C-X C-E) shortcuts to open an external editor. "
              "This is in addition to the F2 binding, which is always enabled."
     ).tag(config=True)
 
     handle_return = Any(None,
         help="Provide an alternative handler to be called when the user presses "
              "Return. This is an advanced option intended for debugging, which "
              "may be changed or removed in later releases."
     ).tag(config=True)
 
     enable_history_search = Bool(True,
         help="Allows to enable/disable the prompt toolkit history search"
     ).tag(config=True)
 
     prompt_includes_vi_mode = Bool(True,
         help="Display the current vi mode (when using vi editing mode)."
     ).tag(config=True)
 
     @observe('term_title')
     def init_term_title(self, change=None):
         # Enable or disable the terminal title.
         if self.term_title:
             toggle_set_term_title(True)
             set_term_title(self.term_title_format.format(cwd=abbrev_cwd()))
         else:
             toggle_set_term_title(False)
 
     def restore_term_title(self):
         if self.term_title:
             restore_term_title()
 
     def init_display_formatter(self):
         super(TerminalInteractiveShell, self).init_display_formatter()
         # terminal only supports plain text
         self.display_formatter.active_types = ['text/plain']
         # disable `_ipython_display_`
         self.display_formatter.ipython_display_formatter.enabled = False
 
     def init_prompt_toolkit_cli(self):
         if self.simple_prompt:
             # Fall back to plain non-interactive output for tests.
             # This is very limited.
             def prompt():
                 prompt_text = "".join(x[1] for x in self.prompts.in_prompt_tokens())
                 lines = [input(prompt_text)]
                 prompt_continuation = "".join(x[1] for x in self.prompts.continuation_prompt_tokens())
                 while self.check_complete('\n'.join(lines))[0] == 'incomplete':
                     lines.append( input(prompt_continuation) )
                 return '\n'.join(lines)
             self.prompt_for_code = prompt
             return
 
         # Set up keyboard shortcuts
         key_bindings = create_ipython_shortcuts(self)
 
         # Pre-populate history from IPython's history database
         history = InMemoryHistory()
         last_cell = u""
         for __, ___, cell in self.history_manager.get_tail(self.history_load_length,
                                                         include_latest=True):
             # Ignore blank lines and consecutive duplicates
             cell = cell.rstrip()
             if cell and (cell != last_cell):
                 history.append_string(cell)
                 last_cell = cell
 
         self._style = self._make_style_from_name_or_cls(self.highlighting_style)
         self.style = DynamicStyle(lambda: self._style)
 
         editing_mode = getattr(EditingMode, self.editing_mode.upper())
 
         self.pt_app = PromptSession(
                             editing_mode=editing_mode,
                             key_bindings=key_bindings,
                             history=history,
                             completer=IPythonPTCompleter(shell=self),
                             enable_history_search = self.enable_history_search,
                             style=self.style,
                             include_default_pygments_style=False,
                             mouse_support=self.mouse_support,
                             enable_open_in_editor=self.extra_open_editor_shortcuts,
                             color_depth=self.color_depth,
                             **self._extra_prompt_options())
 
     def _make_style_from_name_or_cls(self, name_or_cls):
         """
         Small wrapper that make an IPython compatible style from a style name
 
         We need that to add style for prompt ... etc.
         """
         style_overrides = {}
         if name_or_cls == 'legacy':
             legacy = self.colors.lower()
             if legacy == 'linux':
                 style_cls = get_style_by_name('monokai')
                 style_overrides = _style_overrides_linux
             elif legacy == 'lightbg':
                 style_overrides = _style_overrides_light_bg
                 style_cls = get_style_by_name('pastie')
             elif legacy == 'neutral':
                 # The default theme needs to be visible on both a dark background
                 # and a light background, because we can't tell what the terminal
                 # looks like. These tweaks to the default theme help with that.
                 style_cls = get_style_by_name('default')
                 style_overrides.update({
                     Token.Number: '#007700',
                     Token.Operator: 'noinherit',
                     Token.String: '#BB6622',
                     Token.Name.Function: '#2080D0',
                     Token.Name.Class: 'bold #2080D0',
                     Token.Name.Namespace: 'bold #2080D0',
                     Token.Prompt: '#009900',
                     Token.PromptNum: '#ansibrightgreen bold',
                     Token.OutPrompt: '#990000',
                     Token.OutPromptNum: '#ansibrightred bold',
                 })
 
                 # Hack: Due to limited color support on the Windows console
                 # the prompt colors will be wrong without this
                 if os.name == 'nt':
                     style_overrides.update({
                         Token.Prompt: '#ansidarkgreen',
                         Token.PromptNum: '#ansigreen bold',
                         Token.OutPrompt: '#ansidarkred',
                         Token.OutPromptNum: '#ansired bold',
                     })
             elif legacy =='nocolor':
                 style_cls=_NoStyle
                 style_overrides = {}
             else :
                 raise ValueError('Got unknown colors: ', legacy)
         else :
             if isinstance(name_or_cls, str):
                 style_cls = get_style_by_name(name_or_cls)
             else:
                 style_cls = name_or_cls
             style_overrides = {
                 Token.Prompt: '#009900',
                 Token.PromptNum: '#ansibrightgreen bold',
                 Token.OutPrompt: '#990000',
                 Token.OutPromptNum: '#ansibrightred bold',
             }
         style_overrides.update(self.highlighting_style_overrides)
         style = merge_styles([
             style_from_pygments_cls(style_cls),
             style_from_pygments_dict(style_overrides),
         ])
 
         return style
 
     @property
     def pt_complete_style(self):
         return {
             'multicolumn': CompleteStyle.MULTI_COLUMN,
             'column': CompleteStyle.COLUMN,
             'readlinelike': CompleteStyle.READLINE_LIKE,
         }[self.display_completions]
 
     @property
     def color_depth(self):
         return (ColorDepth.TRUE_COLOR if self.true_color else None)
 
     def _extra_prompt_options(self):
         """
         Return the current layout option for the current Terminal InteractiveShell
         """
         def get_message():
             return PygmentsTokens(self.prompts.in_prompt_tokens())
 
         if self.editing_mode == 'emacs':
             # with emacs mode the prompt is (usually) static, so we call only
             # the function once. With VI mode it can toggle between [ins] and
             # [nor] so we can't precompute.
             # here I'm going to favor the default keybinding which almost
             # everybody uses to decrease CPU usage.
             # if we have issues with users with custom Prompts we can see how to
             # work around this.
             get_message = get_message()
 
         return {
                 'complete_in_thread': False,
                 'lexer':IPythonPTLexer(),
                 'reserve_space_for_menu':self.space_for_menu,
                 'message': get_message,
                 'prompt_continuation': (
                     lambda width, lineno, is_soft_wrap:
                         PygmentsTokens(self.prompts.continuation_prompt_tokens(width))),
                 'multiline': True,
                 'complete_style': self.pt_complete_style,
 
                 # Highlight matching brackets, but only when this setting is
                 # enabled, and only when the DEFAULT_BUFFER has the focus.
                 'input_processors': [ConditionalProcessor(
                         processor=HighlightMatchingBracketProcessor(chars='[](){}'),
                         filter=HasFocus(DEFAULT_BUFFER) & ~IsDone() &
                             Condition(lambda: self.highlight_matching_brackets))],
                 'inputhook': self.inputhook,
                 }
 
     def prompt_for_code(self):
         if self.rl_next_input:
             default = self.rl_next_input
             self.rl_next_input = None
         else:
             default = ''
 
         with patch_stdout(raw=True):
             text = self.pt_app.prompt(
                 default=default,
 #                pre_run=self.pre_prompt,# reset_current_buffer=True,
                 **self._extra_prompt_options())
         return text
 
     def enable_win_unicode_console(self):
         # Since IPython 7.10 doesn't support python < 3.6 and PEP 528, Python uses the unicode APIs for the Windows
         # console by default, so WUC shouldn't be needed.
         from warnings import warn
         warn("`enable_win_unicode_console` is deprecated since IPython 7.10, does not do anything and will be removed in the future",
              DeprecationWarning,
              stacklevel=2)
 
     def init_io(self):
         if sys.platform not in {'win32', 'cli'}:
             return
 
         import colorama
         colorama.init()
 
         # For some reason we make these wrappers around stdout/stderr.
         # For now, we need to reset them so all output gets coloured.
         # https://github.com/ipython/ipython/issues/8669
         # io.std* are deprecated, but don't show our own deprecation warnings
         # during initialization of the deprecated API.
         with warnings.catch_warnings():
             warnings.simplefilter('ignore', DeprecationWarning)
             io.stdout = io.IOStream(sys.stdout)
             io.stderr = io.IOStream(sys.stderr)
 
     def init_magics(self):
         super(TerminalInteractiveShell, self).init_magics()
         self.register_magics(TerminalMagics)
 
     def init_alias(self):
         # The parent class defines aliases that can be safely used with any
         # frontend.
         super(TerminalInteractiveShell, self).init_alias()
 
         # Now define aliases that only make sense on the terminal, because they
         # need direct access to the console in a way that we can't emulate in
         # GUI or web frontend
         if os.name == 'posix':
             for cmd in ('clear', 'more', 'less', 'man'):
                 self.alias_manager.soft_define_alias(cmd, cmd)
 
 
     def __init__(self, *args, **kwargs):
         super(TerminalInteractiveShell, self).__init__(*args, **kwargs)
         self.init_prompt_toolkit_cli()
         self.init_term_title()
         self.keep_running = True
 
         self.debugger_history = InMemoryHistory()
 
     def ask_exit(self):
         self.keep_running = False
 
     rl_next_input = None
 
     def interact(self, display_banner=DISPLAY_BANNER_DEPRECATED):
 
         if display_banner is not DISPLAY_BANNER_DEPRECATED:
             warn('interact `display_banner` argument is deprecated since IPython 5.0. Call `show_banner()` if needed.', DeprecationWarning, stacklevel=2)
 
         self.keep_running = True
         while self.keep_running:
             print(self.separate_in, end='')
 
             try:
                 code = self.prompt_for_code()
             except EOFError:
                 if (not self.confirm_exit) \
                         or self.ask_yes_no('Do you really want to exit ([y]/n)?','y','n'):
                     self.ask_exit()
 
             else:
                 if code:
                     self.run_cell(code, store_history=True)
 
     def mainloop(self, display_banner=DISPLAY_BANNER_DEPRECATED):
         # An extra layer of protection in case someone mashing Ctrl-C breaks
         # out of our internal code.
         if display_banner is not DISPLAY_BANNER_DEPRECATED:
             warn('mainloop `display_banner` argument is deprecated since IPython 5.0. Call `show_banner()` if needed.', DeprecationWarning, stacklevel=2)
         while True:
             try:
                 self.interact()
                 break
             except KeyboardInterrupt as e:
                 print("\n%s escaped interact()\n" % type(e).__name__)
             finally:
                 # An interrupt during the eventloop will mess up the
                 # internal state of the prompt_toolkit library.
                 # Stopping the eventloop fixes this, see
                 # https://github.com/ipython/ipython/pull/9867
                 if hasattr(self, '_eventloop'):
                     self._eventloop.stop()
 
                 self.restore_term_title()
 
 
     _inputhook = None
     def inputhook(self, context):
         if self._inputhook is not None:
             self._inputhook(context)
 
     active_eventloop = None
     def enable_gui(self, gui=None):
         if gui:
             self.active_eventloop, self._inputhook =\
                 get_inputhook_name_and_func(gui)
         else:
             self.active_eventloop = self._inputhook = None
 
     # Run !system commands directly, not through pipes, so terminal programs
     # work correctly.
     system = InteractiveShell.system_raw
 
     def auto_rewrite_input(self, cmd):
         """Overridden from the parent class to use fancy rewriting prompt"""
         if not self.show_rewritten_input:
             return
 
         tokens = self.prompts.rewrite_prompt_tokens()
         if self.pt_app:
             print_formatted_text(PygmentsTokens(tokens), end='',
                                  style=self.pt_app.app.style)
             print(cmd)
         else:
             prompt = ''.join(s for t, s in tokens)
             print(prompt, cmd, sep='')
 
     _prompts_before = None
     def switch_doctest_mode(self, mode):
         """Switch prompts to classic for %doctest_mode"""
         if mode:
             self._prompts_before = self.prompts
             self.prompts = ClassicPrompts(self)
         elif self._prompts_before:
             self.prompts = self._prompts_before
             self._prompts_before = None
 #        self._update_layout()
 
 
 InteractiveShellABC.register(TerminalInteractiveShell)
 
 if __name__ == '__main__':
     TerminalInteractiveShell.instance().interact()

IPython/terminal/shortcuts.py

@@ -1,249 +1,274 b''
 """
 Module to define and register Terminal IPython shortcuts with
 :mod:`prompt_toolkit`
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import warnings
 import signal
 import sys
 from typing import Callable
 
 
 from prompt_toolkit.application.current import get_app
 from prompt_toolkit.enums import DEFAULT_BUFFER, SEARCH_BUFFER
 from prompt_toolkit.filters import (has_focus, has_selection, Condition,
     vi_insert_mode, emacs_insert_mode, has_completions, vi_mode)
 from prompt_toolkit.key_binding.bindings.completion import display_completions_like_readline
 from prompt_toolkit.key_binding import KeyBindings
 
 from IPython.utils.decorators import undoc
 
 @undoc
 @Condition
 def cursor_in_leading_ws():
     before = get_app().current_buffer.document.current_line_before_cursor
     return (not before) or before.isspace()
 
 
 def create_ipython_shortcuts(shell):
     """Set up the prompt_toolkit keyboard shortcuts for IPython"""
 
     kb = KeyBindings()
     insert_mode = vi_insert_mode | emacs_insert_mode
 
     if getattr(shell, 'handle_return', None):
         return_handler = shell.handle_return(shell)
     else:
         return_handler = newline_or_execute_outer(shell)
 
     kb.add('enter', filter=(has_focus(DEFAULT_BUFFER)
                             & ~has_selection
                             & insert_mode
                         ))(return_handler)
 
+    def reformat_and_execute(event):
+        reformat_text_before_cursor(event.current_buffer, event.current_buffer.document, shell)
+        event.current_buffer.validate_and_handle()
+
+    kb.add('escape', 'enter', filter=(has_focus(DEFAULT_BUFFER)
+                            & ~has_selection
+                            & insert_mode
+                                      ))(reformat_and_execute)
+
     kb.add('c-\\')(force_exit)
 
     kb.add('c-p', filter=(vi_insert_mode & has_focus(DEFAULT_BUFFER))
                 )(previous_history_or_previous_completion)
 
     kb.add('c-n', filter=(vi_insert_mode & has_focus(DEFAULT_BUFFER))
                 )(next_history_or_next_completion)
 
     kb.add('c-g', filter=(has_focus(DEFAULT_BUFFER) & has_completions)
                 )(dismiss_completion)
 
     kb.add('c-c', filter=has_focus(DEFAULT_BUFFER))(reset_buffer)
 
     kb.add('c-c', filter=has_focus(SEARCH_BUFFER))(reset_search_buffer)
 
     supports_suspend = Condition(lambda: hasattr(signal, 'SIGTSTP'))
     kb.add('c-z', filter=supports_suspend)(suspend_to_bg)
 
     # Ctrl+I == Tab
     kb.add('tab', filter=(has_focus(DEFAULT_BUFFER)
                           & ~has_selection
                           & insert_mode
                           & cursor_in_leading_ws
                         ))(indent_buffer)
     kb.add('c-o', filter=(has_focus(DEFAULT_BUFFER) & emacs_insert_mode)
            )(newline_autoindent_outer(shell.input_transformer_manager))
 
     kb.add('f2', filter=has_focus(DEFAULT_BUFFER))(open_input_in_editor)
 
     if shell.display_completions == 'readlinelike':
         kb.add('c-i', filter=(has_focus(DEFAULT_BUFFER)
                               & ~has_selection
                               & insert_mode
                               & ~cursor_in_leading_ws
                         ))(display_completions_like_readline)
 
     if sys.platform == 'win32':
         kb.add('c-v', filter=(has_focus(DEFAULT_BUFFER) & ~vi_mode))(win_paste)
 
     return kb
 
 
+def reformat_text_before_cursor(buffer, document, shell):
+    text = buffer.delete_before_cursor(len(document.text[:document.cursor_position]))
+    try:
+        formatted_text = shell.reformat_handler(text)
+        buffer.insert_text(formatted_text)
+    except Exception as e:
+        buffer.insert_text(text)
+
+
 def newline_or_execute_outer(shell):
+
     def newline_or_execute(event):
         """When the user presses return, insert a newline or execute the code."""
         b = event.current_buffer
         d = b.document
 
         if b.complete_state:
             cc = b.complete_state.current_completion
             if cc:
                 b.apply_completion(cc)
             else:
                 b.cancel_completion()
             return
 
         # If there's only one line, treat it as if the cursor is at the end.
         # See https://github.com/ipython/ipython/issues/10425
         if d.line_count == 1:
             check_text = d.text
         else:
             check_text = d.text[:d.cursor_position]
         status, indent = shell.check_complete(check_text)
-
+       
+        # if all we have after the cursor is whitespace: reformat current text
+        # before cursor
+        after_cursor = d.text[d.cursor_position:]
+        if not after_cursor.strip():
+            reformat_text_before_cursor(b, d, shell)
         if not (d.on_last_line or
                 d.cursor_position_row >= d.line_count - d.empty_line_count_at_the_end()
                 ):
             if shell.autoindent:
                 b.insert_text('\n' + indent)
             else:
                 b.insert_text('\n')
             return
 
         if (status != 'incomplete') and b.accept_handler:
+            reformat_text_before_cursor(b, d, shell)
             b.validate_and_handle()
         else:
             if shell.autoindent:
                 b.insert_text('\n' + indent)
             else:
                 b.insert_text('\n')
     return newline_or_execute
 
 
 def previous_history_or_previous_completion(event):
     """
     Control-P in vi edit mode on readline is history next, unlike default prompt toolkit.
 
     If completer is open this still select previous completion.
     """
     event.current_buffer.auto_up()
 
 
 def next_history_or_next_completion(event):
     """
     Control-N in vi edit mode on readline is history previous, unlike default prompt toolkit.
 
     If completer is open this still select next completion.
     """
     event.current_buffer.auto_down()
 
 
 def dismiss_completion(event):
     b = event.current_buffer
     if b.complete_state:
         b.cancel_completion()
 
 
 def reset_buffer(event):
     b = event.current_buffer
     if b.complete_state:
         b.cancel_completion()
     else:
         b.reset()
 
 
 def reset_search_buffer(event):
     if event.current_buffer.document.text:
         event.current_buffer.reset()
     else:
         event.app.layout.focus(DEFAULT_BUFFER)
 
 def suspend_to_bg(event):
     event.app.suspend_to_background()
 
 def force_exit(event):
     """
     Force exit (with a non-zero return value)
     """
     sys.exit("Quit")
 
 def indent_buffer(event):
     event.current_buffer.insert_text(' ' * 4)
 
 @undoc
 def newline_with_copy_margin(event):
     """
     DEPRECATED since IPython 6.0
 
     See :any:`newline_autoindent_outer` for a replacement.
 
     Preserve margin and cursor position when using
     Control-O to insert a newline in EMACS mode
     """
     warnings.warn("`newline_with_copy_margin(event)` is deprecated since IPython 6.0. "
       "see `newline_autoindent_outer(shell)(event)` for a replacement.",
                   DeprecationWarning, stacklevel=2)
 
     b = event.current_buffer
     cursor_start_pos = b.document.cursor_position_col
     b.newline(copy_margin=True)
     b.cursor_up(count=1)
     cursor_end_pos = b.document.cursor_position_col
     if cursor_start_pos != cursor_end_pos:
         pos_diff = cursor_start_pos - cursor_end_pos
         b.cursor_right(count=pos_diff)
 
 def newline_autoindent_outer(inputsplitter) -> Callable[..., None]:
     """
     Return a function suitable for inserting a indented newline after the cursor.
 
     Fancier version of deprecated ``newline_with_copy_margin`` which should
     compute the correct indentation of the inserted line. That is to say, indent
     by 4 extra space after a function definition, class definition, context
     manager... And dedent by 4 space after ``pass``, ``return``, ``raise ...``.
     """
 
     def newline_autoindent(event):
         """insert a newline after the cursor indented appropriately."""
         b = event.current_buffer
         d = b.document
 
         if b.complete_state:
             b.cancel_completion()
         text = d.text[:d.cursor_position] + '\n'
         _, indent = inputsplitter.check_complete(text)
         b.insert_text('\n' + (' ' * (indent or 0)), move_cursor=False)
 
     return newline_autoindent
 
 
 def open_input_in_editor(event):
     event.app.current_buffer.tempfile_suffix = ".py"
     event.app.current_buffer.open_in_editor()
 
 
 if sys.platform == 'win32':
     from IPython.core.error import TryNext
     from IPython.lib.clipboard import (ClipboardEmpty,
                                        win32_clipboard_get,
                                        tkinter_clipboard_get)
 
     @undoc
     def win_paste(event):
         try:
             text = win32_clipboard_get()
         except TryNext:
             try:
                 text = tkinter_clipboard_get()
             except (TryNext, ClipboardEmpty):
                 return
         except ClipboardEmpty:
             return
         event.current_buffer.insert_text(text.replace('\t', ' ' * 4))