streams: Add UI warnings for failing events.

Fixes #816.

Author: Abhirup-99

tests/model/test_model.py

@@ -2054,6 +2054,30 @@ def test_is_user_subscribed_to_stream(self, model, stream_dict, stream_id,
 
         assert return_value == expected_response
 
+    @pytest.mark.parametrize('stream_id, expected_response,', [
+            (100, False),
+            (101, False),
+            (3, True),
+        ],
+        ids=[
+            'subscribed_pinned_stream',
+            'subscribed_unpinned_stream',
+            'unsubscribed_stream',
+        ]
+    )
+    def test_is_user_in_unsubscribed_stream(self, model, stream_dict,
+                                            stream_id, expected_response,
+                                            initial_pinned_streams,
+                                            initial_unpinned_streams):
+
+        model.pinned_streams = deepcopy(initial_pinned_streams)
+        model.unpinned_streams = deepcopy(initial_unpinned_streams)
+        return_value = model.is_user_in_unsubscribed_stream(stream_id)
+
+        assert model.pinned_streams == initial_pinned_streams
+        assert model.unpinned_streams == initial_unpinned_streams
+        assert return_value == expected_response
+
     @pytest.mark.parametrize('response', [{
         'result': 'success',
         'msg': '',

tests/ui/test_ui_tools.py

@@ -81,6 +81,7 @@ def mock_external_classes(self, mocker):
         self.model = mocker.MagicMock()
         self.view = mocker.Mock()
         self.urwid = mocker.patch(VIEWS + ".urwid")
+        self.model.controller.check_for_invalid_operation.return_value = False
 
     @pytest.fixture
     def msg_view(self, mocker, msg_box):
@@ -820,6 +821,7 @@ def mock_external_classes(self, mocker):
         self.super = mocker.patch(VIEWS + '.urwid.Frame.__init__')
         self.super_keypress = mocker.patch(VIEWS + '.urwid.Frame.keypress')
         self.model.controller == mocker.Mock()
+        self.model.controller.check_for_invalid_operation.return_value = False
 
     @pytest.fixture
     def mid_col_view(self):
@@ -1268,6 +1270,7 @@ class TestMessageBox:
     def mock_external_classes(self, mocker, initial_index):
         self.model = mocker.MagicMock()
         self.model.index = initial_index
+        self.model.controller.check_for_invalid_operation.return_value = False
 
     @pytest.mark.parametrize('message_type, set_fields', [
         ('stream',
@@ -1877,7 +1880,9 @@ def test_main_view_generates_EDITED_label(self, mocker,
     ])
     def test_keypress_STREAM_MESSAGE(self, mocker, msg_box, widget_size,
                                      narrow, expect_to_prefill, key):
-        write_box = msg_box.model.controller.view.write_box
+        controller = msg_box.model.controller
+        controller.check_for_invalid_operation.return_value = False
+        write_box = controller.view.write_box
         msg_box.model.narrow = narrow
         size = widget_size(msg_box)
 

tests/ui_tools/test_boxes.py

@@ -18,6 +18,7 @@ class TestWriteBox:
     def mock_external_classes(self, mocker, initial_index):
         self.view = mocker.Mock()
         self.view.model = mocker.Mock()
+        self.view.model.is_user_in_unsubscribed_stream.return_value = False
 
     @pytest.fixture()
     def write_box(self, mocker, users_fixture, user_groups_fixture,

zulipterminal/core.py

@@ -102,6 +102,15 @@ def raise_exception_in_main_thread(self,
             self._critical_exception = True
         os.write(self._exception_pipe, b'1')
 
+    def check_for_invalid_operation(self, stream_id: Optional[int]) -> bool:
+        assert stream_id is not None
+        if self.model.is_user_in_unsubscribed_stream(stream_id):
+            self.model.controller.view.set_footer_text(
+                " This is not allowed in unsubscribed streams.",
+                3)
+            return True
+        return False
+
     def is_in_editor_mode(self) -> bool:
         return self._editor is not None
 

zulipterminal/model.py

@@ -817,6 +817,10 @@ def toggle_stream_pinned_status(self, stream_id: int) -> bool:
     def is_user_subscribed_to_stream(self, stream_id: int) -> bool:
         return stream_id in self.stream_dict
 
+    def is_user_in_unsubscribed_stream(self, stream_id: int) -> bool:
+        return not(self.is_stream_in_list(stream_id, self.pinned_streams)
+                   or self.is_stream_in_list(stream_id, self.unpinned_streams))
+
     def _get_stream_by_id(self, streams: List[StreamData], stream_id: int
                           ) -> StreamData:
         for stream in streams:

zulipterminal/ui_tools/boxes.py

@@ -1388,10 +1388,13 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
                     stream_id=self.stream_id,
                 )
         elif is_command_key('STREAM_MESSAGE', key):
+            stream_id = self.stream_id
+            if self.model.controller.check_for_invalid_operation(stream_id):
+                return None
             if len(self.model.narrow) == 2:
                 self.model.controller.view.write_box.stream_box_view(
                     caption=self.message['display_recipient'],
-                    stream_id=self.stream_id,
+                    stream_id=stream_id,
                 )
             else:
                 self.model.controller.view.write_box.stream_box_view(0)
@@ -1429,6 +1432,10 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
                 recipient_user_ids=[self.message['sender_id']],
             )
         elif is_command_key('MENTION_REPLY', key):
+            stream_id = self.stream_id
+            if self.model.controller.check_for_invalid_operation(stream_id):
+                return key
+
             self.keypress(size, 'enter')
             mention = f"@**{self.message['sender_full_name']}** "
             self.model.controller.view.write_box.msg_write_box.set_edit_text(

zulipterminal/ui_tools/views.py

@@ -556,10 +556,12 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
             return key
 
         elif is_command_key('STREAM_MESSAGE', key):
+            stream_id = self.model.stream_id
+            if self.model.controller.check_for_invalid_operation(stream_id):
+                return None
             self.body.keypress(size, 'c')
             # For new streams with no previous conversation.
             if self.footer.focus is None:
-                stream_id = self.model.stream_id
                 stream_dict = self.model.stream_dict
                 self.footer.stream_box_view(
                     caption=stream_dict[stream_id]['name'])