Add support for opening message in browser.

docs/hotkeys.md

@@ -55,6 +55,7 @@
 |Add/remove star status of the current message|<kbd>ctrl</kbd> + <kbd>s</kbd> / <kbd>*</kbd>|
 |Show/hide message information|<kbd>i</kbd>|
 |Show/hide edit history (from message information)|<kbd>e</kbd>|
+|View current message in browser (from message information)|<kbd>v</kbd>|
 
 ## Stream list actions
 |Command|Key Combination|

tests/core/test_core.py

@@ -1,3 +1,5 @@
+import os
+import webbrowser
 from platform import platform
 from typing import Any
 
@@ -265,6 +267,38 @@ def test_narrow_to_all_mentions(self, mocker, controller, index_all_mentions):
         msg_ids = {widget.original_widget.message["id"] for widget in widgets}
         assert msg_ids == id_list
 
+    @pytest.mark.parametrize(
+        "url",
+        [
+            "https://chat.zulip.org/#narrow/stream/test",
+            "https://chat.zulip.org/user_uploads/sent/abcd/efg.png",
+            "https://github.com/",
+        ],
+    )
+    def test_open_in_browser_success(self, mocker, controller, url):
+        # Set DISPLAY environ to be able to run test in CI
+        os.environ["DISPLAY"] = ":0"
+        controller.view.set_footer_text = mocker.Mock()
+        mock_get = mocker.patch(CORE + ".webbrowser.get")
+        mock_open = mock_get.return_value.open
+
+        controller.open_in_browser(url)
+
+        mock_open.assert_called_once_with(url)
+        controller.view.set_footer_text.assert_called_once_with(
+            f"The link was successfully opened using {mock_get.return_value.name}", 3
+        )
+
+    def test_open_in_browser_fail__no_browser_controller(self, mocker, controller):
+        os.environ["DISPLAY"] = ":0"
+        error = "No runnable browser found"
+        controller.view.set_footer_text = mocker.Mock()
+        mocker.patch(CORE + ".webbrowser.get").side_effect = webbrowser.Error(error)
+
+        controller.open_in_browser("https://chat.zulip.org/#narrow/stream/test")
+
+        controller.view.set_footer_text.assert_called_once_with(f"ERROR: {error}", 3)
+
     def test_main(self, mocker, controller):
         controller.view.palette = {"default": "theme_properties"}
         mock_tsk = mocker.patch("zulipterminal.ui.Screen.tty_signal_keys")

tests/ui_tools/test_popups.py

@@ -580,8 +580,18 @@ def test_keypress_exit_popup(self, key, widget_size):
         self.msg_info_view.keypress(size, key)
         assert self.controller.exit_popup.called
 
+    @pytest.mark.parametrize("key", keys_for_command("VIEW_IN_BROWSER"))
+    def test_keypress_view_in_browser(self, mocker, widget_size, message_fixture, key):
+        size = widget_size(self.msg_info_view)
+        self.msg_info_view.server_url = "https://chat.zulip.org/"
+        mocker.patch(VIEWS + ".near_message_url")
+
+        self.msg_info_view.keypress(size, key)
+
+        assert self.controller.open_in_browser.called
+
     def test_height_noreactions(self):
-        expected_height = 3
+        expected_height = 4
         assert self.msg_info_view.height == expected_height
 
     # FIXME This is the same parametrize as MessageBox:test_reactions_view
@@ -644,8 +654,9 @@ def test_height_reactions(self, message_fixture, to_vary_in_each_message):
             OrderedDict(),
             list(),
         )
-        # 9 = 3 labels + 1 blank line + 1 'Reactions' (category) + 4 reactions.
-        expected_height = 9
+        # 10 = 4 labels + 1 blank line + 1 'Reactions' (category)
+        # + 4 reactions (excluding 'Message Links').
+        expected_height = 10
         assert self.msg_info_view.height == expected_height
 
     @pytest.mark.parametrize(

zulipterminal/config/keys.py

@@ -236,6 +236,13 @@ class KeyBinding(TypedDict, total=False):
         'excluded_from_random_tips': True,
         'key_category': 'msg_actions',
     }),
+    ('VIEW_IN_BROWSER', {
+        'keys': ['v'],
+        'help_text':
+            'View current message in browser (from message information)',
+        'excluded_from_random_tips': True,
+        'key_category': 'msg_actions',
+    }),
     ('STREAM_DESC', {
         'keys': ['i'],
         'help_text': 'Show/hide stream information & modify settings',

zulipterminal/core.py

@@ -2,6 +2,7 @@
 import signal
 import sys
 import time
+import webbrowser
 from collections import OrderedDict
 from functools import partial
 from platform import platform
@@ -14,7 +15,7 @@
 
 from zulipterminal.api_types import Composition, Message
 from zulipterminal.config.themes import ThemeSpec
-from zulipterminal.helper import asynch
+from zulipterminal.helper import LINUX, asynch, suppress_output
 from zulipterminal.model import Model
 from zulipterminal.ui import Screen, View
 from zulipterminal.ui_tools.utils import create_msg_box_list
@@ -304,6 +305,35 @@ def show_edit_history(
             "area:msg",
         )
 
+    def open_in_browser(self, url: str) -> None:
+        """
+        Opens any provided URL in a graphical browser, if found, else
+        prints an appropriate error message.
+        """
+        # Don't try to open web browser if running without a GUI
+        # TODO: Explore and eventually support opening links in text-browsers.
+        if LINUX and not os.environ.get("DISPLAY") and os.environ.get("TERM"):
+            self.view.set_footer_text(
+                "No DISPLAY environment variable specified. This could "
+                "likely mean the ZT host is running without a GUI.",
+                3,
+            )
+            return
+        try:
+            # Checks for a runnable browser in the system and returns
+            # its browser controller, if found, else reports an error
+            browser_controller = webbrowser.get()
+            # Suppress stdout and stderr when opening browser
+            with suppress_output():
+                browser_controller.open(url)
+                self.view.set_footer_text(
+                    f"The link was successfully opened using {browser_controller.name}",
+                    3,
+                )
+        except webbrowser.Error as e:
+            # Set a footer text if no runnable browser is located
+            self.view.set_footer_text(f"ERROR: {e}", 3)
+
     def search_messages(self, text: str) -> None:
         # Search for a text in messages
         self.model.index["search"].clear()

zulipterminal/helper.py

@@ -3,6 +3,7 @@
 import subprocess
 import time
 from collections import OrderedDict, defaultdict
+from contextlib import contextmanager
 from functools import wraps
 from itertools import chain, combinations
 from re import ASCII, MULTILINE, findall, match
@@ -14,6 +15,7 @@
     Dict,
     FrozenSet,
     Iterable,
+    Iterator,
     List,
     Set,
     Tuple,
@@ -714,3 +716,22 @@ def get_unused_fence(content: str) -> str:
         max_length_fence = max(max_length_fence, len(max(matches, key=len)) + 1)
 
     return "`" * max_length_fence
+
+
+@contextmanager
+def suppress_output() -> Iterator[None]:
+    """
+    Context manager to redirect stdout and stderr to /dev/null.
+
+    Adapted from https://stackoverflow.com/a/2323563
+    """
+    stdout = os.dup(1)
+    stderr = os.dup(2)
+    os.close(1)
+    os.close(2)
+    os.open(os.devnull, os.O_RDWR)
+    try:
+        yield
+    finally:
+        os.dup2(stdout, 1)
+        os.dup2(stderr, 2)

zulipterminal/ui_tools/views.py

@@ -25,6 +25,7 @@
 )
 from zulipterminal.config.ui_mappings import EDIT_MODE_CAPTIONS
 from zulipterminal.helper import Message, asynch, match_stream, match_user
+from zulipterminal.server_url import near_message_url
 from zulipterminal.ui_tools.boxes import MessageBox, PanelSearchBox
 from zulipterminal.ui_tools.buttons import (
     HomeButton,
@@ -1297,9 +1298,11 @@ def __init__(
         self.topic_links = topic_links
         self.message_links = message_links
         self.time_mentions = time_mentions
+        self.server_url = controller.model.server_url
         date_and_time = controller.model.formatted_local_time(
             msg["timestamp"], show_seconds=True, show_year=True
         )
+        view_in_browser_keys = ", ".join(map(repr, keys_for_command("VIEW_IN_BROWSER")))
 
         msg_info = [
             (
@@ -1308,6 +1311,10 @@ def __init__(
                     ("Date & Time", date_and_time),
                     ("Sender", msg["sender_full_name"]),
                     ("Sender's Email ID", msg["sender_email"]),
+                    (
+                        "View message in browser",
+                        f"Press {view_in_browser_keys} to view message in browser",
+                    ),
                 ],
             ),
         ]
@@ -1410,6 +1417,9 @@ def keypress(self, size: urwid_Size, key: str) -> str:
                 message_links=self.message_links,
                 time_mentions=self.time_mentions,
             )
+        elif is_command_key("VIEW_IN_BROWSER", key):
+            url = near_message_url(self.server_url[:-1], self.msg)
+            self.controller.open_in_browser(url)
         return super().keypress(size, key)