core/views: Use near_message_url to open messages in the topic narrow.

This improves view_in_browser to open messages in the exact/topic narrow
for streams and in the pm-with narrow for PMs and huddles.

Tests amended.

tests/core/test_core.py

@@ -236,17 +236,20 @@ def test_show_all_mentions(self, mocker, controller, index_all_mentions):
         msg_ids = {widget.original_widget.message['id'] for widget in widgets}
         assert msg_ids == id_list
 
-    def test_view_in_browser(self, mocker, controller):
+    @pytest.mark.parametrize('server_url', [
+        'https://chat.zulip.org/',
+        'https://foo.zulipchat.com/',
+    ])
+    def test_view_in_browser(self, mocker, controller, message_fixture,
+                             server_url):
         # Set DISPLAY environ to be able to run test in Travis
         os.environ['DISPLAY'] = ':0'
-        mock_open = mocker.patch('webbrowser.open', mocker.Mock())
-        message_id = 123456
-        controller.model.server_url = 'https://foo.zulipchat.com/'
-        controller.view_in_browser(message_id)
-        assert mock_open.call_count == 1
-        url = mock_open.call_args[0][0]
-        assert url.startswith(controller.model.server_url)
-        assert url.endswith('/{}'.format(message_id))
+        controller.model.server_url = server_url
+        mocked_open = mocker.patch(CORE + '.webbrowser.open')
+
+        controller.view_in_browser(message_fixture)
+
+        mocked_open.assert_called_once_with(controller.url)
 
     def test_main(self, mocker, controller):
         ret_mock = mocker.Mock()

tests/ui/test_ui_tools.py

@@ -1475,7 +1475,7 @@ def test_keypress_view_in_browser(self, message_fixture, key):
         size = (200, 20)
         self.msg_info_view.keypress(size, key)
         (self.controller.view_in_browser.
-         assert_called_once_with(message_fixture['id']))
+         assert_called_once_with(message_fixture))
 
     def test_height_noreactions(self):
         expected_height = 4

zulipterminal/core.py

@@ -12,7 +12,9 @@
 import zulip
 
 from zulipterminal.config.themes import ThemeSpec
-from zulipterminal.helper import MACOS, WSL, Message, asynch, suppress_output
+from zulipterminal.helper import (
+    MACOS, WSL, Message, asynch, near_message_url, suppress_output,
+)
 from zulipterminal.model import Model
 from zulipterminal.ui import Screen, View
 from zulipterminal.ui_tools.utils import create_msg_box_list
@@ -287,15 +289,16 @@ def show_all_mentions(self, button: Any) -> None:
                         anchor=None,
                         mentioned=True)
 
-    def view_in_browser(self, message_id: int) -> None:
-        url = '{}#narrow/near/{}'.format(self.model.server_url, message_id)
+    def view_in_browser(self, message: Message) -> None:
+        # Truncate extra '/' from the server url.
+        self.url = near_message_url(self.model.server_url[:-1], message)
         if (not MACOS and not WSL and not os.environ.get('DISPLAY')
                 and os.environ.get('TERM')):
             # Don't try to open web browser if running without a GUI
             return
         with suppress_output():
             # Suppress anything on stdout or stderr when opening the browser
-            webbrowser.open(url)
+            webbrowser.open(self.url)
 
     def deregister_client(self) -> None:
         queue_id = self.model.queue_id

zulipterminal/ui_tools/views.py

@@ -1116,5 +1116,5 @@ def __init__(self, controller: Any, msg: Message, title: str,
 
     def keypress(self, size: urwid_Size, key: str) -> str:
         if is_command_key('VIEW_IN_BROWSER', key):
-            self.controller.view_in_browser(self.msg['id'])
+            self.controller.view_in_browser(self.msg)
         return super().keypress(size, key)