bugdown: Refactor get_possible_mentions_info and related functions.

This commit changes the return type of get_possible_mentions_info  to a
list instead of a dict, thus disposing off the hacky logic of storing
users with duplicate full names with name|id keys that made the code
obfuscated.

The other functions continue to use the dicts as before, however, there
are minor variable changes where needed in accordance with the updated
definition of get_possible_mentions_info.

zerver/lib/bugdown/__init__.py

@@ -1877,21 +1877,24 @@ def get_email_info(realm_id: int, emails: Set[str]) -> Dict[str, FullNameInfo]:
     }
     return dct
 
-def get_possible_mentions_info(realm_id: int, mention_texts: Set[str]) -> Dict[str, FullNameInfo]:
+def get_possible_mentions_info(realm_id: int, mention_texts: Set[str]) -> List[FullNameInfo]:
     if not mention_texts:
-        return dict()
+        return list()
 
-    # Remove the trailing part of the `user|id` mention syntax.
+    # Remove the trailing part of the `name|id` mention syntax,
+    # thus storing only full names in full_names.
+    full_names = set()
     name_re = r'(?P<full_name>.+)\|\d+$'
-    for mention_text in mention_texts.copy():
+    for mention_text in mention_texts:
         name_syntax_match = re.match(name_re, mention_text)
         if name_syntax_match:
-            mention_texts.remove(mention_text)
-            mention_texts.add(name_syntax_match.group("full_name"))
+            full_names.add(name_syntax_match.group("full_name"))
+        else:
+            full_names.add(mention_text)
 
     q_list = {
-        Q(full_name__iexact=mention_text)
-        for mention_text in mention_texts
+        Q(full_name__iexact=full_name)
+        for full_name in full_names
     }
 
     rows = UserProfile.objects.filter(
@@ -1904,22 +1907,19 @@ def get_possible_mentions_info(realm_id: int, mention_texts: Set[str]) -> Dict[s
         'full_name',
         'email',
     )
-    dct = {}  # type: Dict[str, FullNameInfo]
-    for row in rows:
-        key = row['full_name'].lower()
-        # To insert users with duplicate full names in the dict
-        if key in dct:
-            key = '{}|{}'.format(key, row['id'])
-        dct[key] = row
-    return dct
+    return list(rows)
 
 class MentionData:
     def __init__(self, realm_id: int, content: str) -> None:
         mention_texts = possible_mentions(content)
-        self.full_name_info = get_possible_mentions_info(realm_id, mention_texts)
+        possible_mentions_info = get_possible_mentions_info(realm_id, mention_texts)
+        self.full_name_info = {
+            row['full_name'].lower(): row
+            for row in possible_mentions_info
+        }
         self.user_id_info = {
             row['id']: row
-            for row in self.full_name_info.values()
+            for row in possible_mentions_info
         }
         self.init_user_group_data(realm_id=realm_id, content=content)
 

zerver/tests/test_bugdown.py

@@ -199,16 +199,21 @@ class BugdownMiscTest(ZulipTestCase):
         fred3.save()
 
         fred4 = make_user('fred4@example.com', 'Fred Flintstone')
-        fred4_key = 'fred flintstone|{}'.format(fred4.id)
 
-        dct = bugdown.get_possible_mentions_info(realm.id, {'Fred Flintstone', 'cordelia LEAR', 'Not A User'})
-        self.assertEqual(set(dct.keys()), {'fred flintstone', fred4_key, 'cordelia lear'})
-        self.assertEqual(dct['fred flintstone'], dict(
+        lst = bugdown.get_possible_mentions_info(realm.id, {'Fred Flintstone', 'cordelia LEAR', 'Not A User'})
+        set_of_names = set(map(lambda x: x['full_name'].lower(), lst))
+        self.assertEqual(set_of_names, {'fred flintstone', 'cordelia lear'})
+
+        by_id = {
+            row['id']: row
+            for row in lst
+        }
+        self.assertEqual(by_id.get(fred2.id), dict(
             email='fred2@example.com',
             full_name='Fred Flintstone',
             id=fred2.id
         ))
-        self.assertEqual(dct[fred4_key], dict(
+        self.assertEqual(by_id.get(fred4.id), dict(
             email='fred4@example.com',
             full_name='Fred Flintstone',
             id=fred4.id