kj key_bindings for vim mode

pgcli/key_bindings.py

@@ -1,7 +1,11 @@
 import logging
 from prompt_toolkit.enums import EditingMode
+from prompt_toolkit.keys import Keys
 from prompt_toolkit.key_binding import KeyBindings
+from prompt_toolkit.key_binding.key_processor import KeyPress
 from prompt_toolkit.filters import (
+    Condition,
+    ViInsertMode,
     completion_is_selected,
     is_searching,
     has_completions,
@@ -124,4 +128,12 @@ def _(event):
         """Move down in history."""
         event.current_buffer.history_forward(count=event.arg)
 
+    @kb.add("k", "j", filter=ViInsertMode())
+    def _(event):
+        """
+        Typing 'kj' in Insert mode, should go back to navigation mode.
+        """
+        _logger.debug('Detected kj keys.')
+        event.cli.key_processor.feed(KeyPress(Keys.Escape))
+
     return kb