bugfix: boxes: Send typing 'stop' event only after prior 'start' event.

This commit adds an extra check before sending typing 'stop' events
through the 'sent_start_typing_status' boolean which indicates whether a
'start' event has already been sent. This avoids sending unnecessary
'stop' events.

Test updated.

tests/ui_tools/test_boxes.py

@@ -53,6 +53,7 @@ def test_init(self, write_box):
         assert write_box.model == self.view.model
         assert write_box.view == self.view
         assert write_box.msg_edit_state is None
+        assert not write_box.sent_start_typing_status
 
     def test_not_calling_typing_method_without_recipients(self, mocker, write_box):
         write_box.model.send_typing_status_by_user_ids = mocker.Mock()

zulipterminal/ui_tools/boxes.py

@@ -89,6 +89,7 @@ def __init__(self, view: Any) -> None:
         self.send_next_typing_update = datetime.now()
         self.last_key_update = datetime.now()
         self.idle_status_tracking = False
+        self.sent_start_typing_status = False
 
         # Constant indices into self.contents
         # (CONTAINER=vertical, HEADER/MESSAGE=horizontal)
@@ -114,13 +115,19 @@ def set_editor_mode(self) -> None:
         self.view.controller.enter_editor_mode_with(self)
 
     def send_stop_typing_status(self) -> None:
-        # Send 'stop' updates only for PM narrows.
-        if self.to_write_box and self.recipient_user_ids:
+        # Send 'stop' updates only for PM narrows, when there are recipients
+        # to send to and a prior 'start' status has already been sent.
+        if (
+            self.to_write_box
+            and self.recipient_user_ids
+            and self.sent_start_typing_status
+        ):
             self.model.send_typing_status_by_user_ids(
                 self.recipient_user_ids, status="stop"
             )
             self.send_next_typing_update = datetime.now()
             self.idle_status_tracking = False
+            self.sent_start_typing_status = False
 
     def private_box_view(
         self,
@@ -202,6 +209,7 @@ def on_type_send_status(edit: object, new_edit_text: str) -> None:
                         self.recipient_user_ids, status="start"
                     )
                     self.send_next_typing_update += start_period_delta
+                    self.sent_start_typing_status = True
                     # Initiate tracker function only if it isn't already
                     # initiated.
                     if not self.idle_status_tracking: