model: Fetch and store custom emojis.

* Fetch custom emojis from server which can be used be the user
  using typeahead.
* Model tests amended.
* New fixture and test added for custom emojis.

Minor note:
The emojis are being sorted twice here, once when unicode emojis
are stored in the file using the script ( which happens occasionally
when it is manually updated ) and again after custom emojis are fetched
( which happens during every load ). The first sorting seems pointless,
at first glance, but it improves sorting time since python's sorted()
function uses Timsort that can perform better if subsequences of the data
are already sorted.

Author: kaustubh-nair

tests/conftest.py

@@ -177,6 +177,15 @@ def streams_fixture():
     return deepcopy(streams)
 
 
+@pytest.fixture
+def custom_emojis():
+    return OrderedDict([
+        ('urwid', {'code': '100', 'type': 'realm_emoji'}),
+        ('dancing', {'code': '3', 'type': 'realm_emoji'}),
+        ('snape', {'code': '20', 'type': 'realm_emoji'}),
+    ])
+
+
 @pytest.fixture
 def unicode_emojis():
     return OrderedDict([

tests/model/test_model.py

@@ -1,4 +1,5 @@
 import json
+from collections import OrderedDict
 from typing import Any
 
 import pytest
@@ -22,7 +23,7 @@ def mock_external_classes(self, mocker: Any) -> None:
 
     @pytest.fixture
     def model(self, mocker, initial_data, user_profile,
-              unicode_emojis):
+              unicode_emojis, custom_emojis):
         mocker.patch('zulipterminal.model.Model.get_messages',
                      return_value='')
         self.client.register.return_value = initial_data
@@ -38,11 +39,13 @@ def model(self, mocker, initial_data, user_profile,
         self.client.get_profile.return_value = user_profile
         mocker.patch('zulipterminal.model.emoji_data',
                      EMOJI_DATA=unicode_emojis)
+        mocker.patch('zulipterminal.model.Model.fetch_custom_emojis',
+                     return_value=custom_emojis)
         model = Model(self.controller)
         return model
 
     def test_init(self, model, initial_data, user_profile,
-                  unicode_emojis):
+                  unicode_emojis, custom_emojis):
         assert hasattr(model, 'controller')
         assert hasattr(model, 'client')
         assert model.msg_view is None
@@ -74,7 +77,11 @@ def test_init(self, model, initial_data, user_profile,
         assert model.unpinned_streams == []
         self.classify_unread_counts.assert_called_once_with(model)
         assert model.unread_counts == []
-        assert model.emoji_data == unicode_emojis
+        assert unicode_emojis.items() <= model.emoji_data.items()
+        assert custom_emojis.items() <= model.emoji_data.items()
+        print(model.emoji_data)
+        assert model.emoji_data == OrderedDict(sorted(
+                            model.emoji_data.items(), key=lambda e: e[0]))
 
     def test_init_InvalidAPIKey_response(self, mocker, initial_data):
         # Both network calls indicate the same response
@@ -1452,3 +1459,47 @@ def test_is_muted_topic(self, topic, is_muted, stream_dict, model):
         ]
         assert model.is_muted_topic(stream_id=topic[0],
                                     topic=topic[1]) == is_muted
+
+    @pytest.mark.parametrize('response', [
+        {
+            'emoji': {
+                '100': {
+                    'author_id': 5,
+                    'deactivated': False,
+                    'id': '100',
+                    'name': 'urwid',
+                    'source_url': '/user_avatars/1/emoji/images/1.png'
+                },
+                '20': {
+                    'author_id': 10,
+                    'deactivated': False,
+                    'id': '20',
+                    'name': 'snape',
+                    'source_url': '/user_avatars/2/emoji/images/2.png'
+                },
+                '3': {
+                    'author_id': 5,
+                    'deactivated': False,
+                    'id': '3',
+                    'name': 'dancing',
+                    'source_url': '/user_avatars/3/emoji/images/3.png'
+                },
+                '81': {
+                    'author_id': 5,
+                    'deactivated': True,
+                    'id': '81',
+                    'name': 'green_tick',
+                    'source_url': '/user_avatars/4/emoji/images/4.png'
+                },
+            },
+            'msg': '',
+            'result': 'success'
+        }
+    ])
+    def test_fetch_custom_emojis(self, mocker, model, custom_emojis,
+                                 response):
+        self.client.get_realm_emoji.return_value = response
+
+        fetched_custom_emojis = model.fetch_custom_emojis()
+
+        assert fetched_custom_emojis == custom_emojis

zulipterminal/model.py

@@ -121,7 +121,11 @@ def __init__(self, controller: Any) -> None:
         self.unread_counts = classify_unread_counts(self)
 
         self.fetch_all_topics(workers=5)
-        self.emoji_data = emoji_data.EMOJI_DATA
+
+        custom_emojis = self.fetch_custom_emojis()
+        all_emojis = (list(emoji_data.EMOJI_DATA.items())
+                      + list(custom_emojis.items()))
+        self.emoji_data = OrderedDict(sorted(all_emojis, key=lambda e: e[0]))
 
         self.new_user_input = True
         self._start_presence_updates()
@@ -332,6 +336,15 @@ def update_stream_message(self, topic: str, msg_id: int,
         response = self.client.update_message(request)
         return response['result'] == 'success'
 
+    def fetch_custom_emojis(self) -> Dict[str, Dict[str, str]]:
+        response = self.client.get_realm_emoji()
+        custom_emojis = {}
+        for emoji_code, emoji in response['emoji'].items():
+            if not emoji['deactivated']:
+                custom_emojis[emoji['name']] = {'code': emoji_code,
+                                                'type': 'realm_emoji'}
+        return custom_emojis
+
     def get_messages(self, *,
                      num_after: int, num_before: int,
                      anchor: Optional[int]) -> str: