tests: helper: Test set_count for private messages.

Add test for verifying unread_counts when marking pms as read/unread.

Add pm message entries to index fixture.

Author: kaustubh-nair

tests/conftest.py

@@ -771,6 +771,8 @@ def initial_unread_counts():
 def index_multiple_messages():
     """
     Index fixture filled with multiple entries for messages.
+    Private messages have minimal data required to test `set_count`.
+    More can be added if and when required.
     """
     return dict(helper_initial_index, **{'messages': {
         1: {'id': 1, 'type': 'stream', 'subject': 'Topic 1', 'sender_id': 99,
@@ -791,6 +793,21 @@ def index_multiple_messages():
             'stream_id': 1003, 'display_recipient': 'stream 10'},
         9: {'id': 9, 'type': 'stream', 'subject': 'Topic 10', 'sender_id': 101,
             'stream_id': 1003, 'display_recipient': 'stream 10'},
+        # pms
+        10: {'id': 10, 'type': 'private', 'sender_id': 200,
+             'display_recipient': [{'id': 202}, {'id': 200}]},
+        11: {'id': 11, 'type': 'private', 'sender_id': 201,
+             'display_recipient': [{'id': 202}, {'id': 201}]},
+        12: {'id': 12, 'type': 'private', 'sender_id': 202,
+             'display_recipient': [{'id': 202}, {'id': 201}]},
+        13: {'id': 13, 'type': 'private', 'sender_id': 200,
+             'display_recipient': [{'id': 202}, {'id': 200}]},
+        14: {'id': 14, 'type': 'private', 'sender_id': 201,
+             'display_recipient': [{'id': 202}, {'id': 201}]},
+        15: {'id': 15, 'type': 'private', 'sender_id': 202,
+             'display_recipient': [{'id': 202}]},
+        16: {'id': 16, 'type': 'private', 'sender_id': 200,
+             'display_recipient': [{'id': 202}, {'id': 200}]},
         }})
 # --------------- UI Fixtures -----------------------------------------
 

tests/helper/test_helper.py

@@ -47,6 +47,38 @@ def test_set_count_stream(mocker, initial_unread_counts,
     assert controller.model.unread_counts == expected_unread_counts
 
 
+@pytest.mark.parametrize('all_msg, all_pms, unread_pms, user_id', [
+    (4, 3, {200: 2, 201: 1}, 202)
+    ])
+@pytest.mark.parametrize(('new_count, id_list, expected_all_msg,'
+                         'expected_all_pms, expected_unread_pms'), [
+    (-1, [10, 13], 2, 1, {201: 1}),
+    (-1, [10, 13, 11], 1, 0, {}),
+    (-1, [], 4, 3, {200: 2, 201: 1}),
+    (-1, [15], 4, 3, {200: 2, 201: 1}),   # self-pm
+    (1, [16, 10], 6, 5, {200: 4, 201: 1}),
+    (1, [], 4, 3, {200: 2, 201: 1}),
+    ])
+def test_set_count_pms(mocker, initial_unread_counts, all_msg,
+                       all_pms, unread_pms, user_id, id_list, new_count,
+                       expected_unread_pms, expected_all_pms,
+                       expected_all_msg, index_multiple_messages):
+    controller = mocker.patch('zulipterminal.core.Controller.__init__')
+    controller.model.index = index_multiple_messages
+    controller.model.user_id = user_id
+
+    unread_counts = deepcopy(dict(initial_unread_counts,
+                                  **{'all_msg': all_msg, 'all_pms': all_pms,
+                                     'unread_pms': unread_pms}))
+    expected_unread_counts = dict(initial_unread_counts,
+                                  **{'all_msg': expected_all_msg,
+                                     'all_pms': expected_all_pms,
+                                     'unread_pms': expected_unread_pms})
+    controller.model.unread_counts = unread_counts
+    set_count(id_list, controller, new_count)
+    assert controller.model.unread_counts == expected_unread_counts
+
+
 def test_index_messages_narrow_all_messages(mocker,
                                             messages_successful_response,
                                             index_all_messages,