boxes: Use user_ids in autocomplete for ambiguous user mentions.

Prior to this commit, user mentions through autocomplete used only
names in the typeahead. This commit appends `user_id`s to all the
multiple instances of the same name to use the **Name|User_id** format of
user mentions.

This is done by using collections.Counter to check the count of each user
name in the users list. The user_id is appended to names that have a count
greater than 1. The appended user_id would serve as a distinction
between users having the same name.

Tests added and updated.

Fixes zulip#151.

Author: prah23

tests/ui_tools/test_boxes.py

@@ -221,19 +221,19 @@ def test_generic_autocomplete_set_footer(
             ("@Human", 0, "@**Human Myself**"),
             ("@Human", 1, "@**Human 1**"),
             ("@Human", 2, "@**Human 2**"),
-            ("@Human", 3, "@**Human Duplicate**"),
-            ("@Human", 4, "@**Human Duplicate**"),
-            ("@Human", -1, "@**Human Duplicate**"),
-            ("@Human", -2, "@**Human Duplicate**"),
+            ("@Human", 3, "@**Human Duplicate|13**"),
+            ("@Human", 4, "@**Human Duplicate|14**"),
+            ("@Human", -1, "@**Human Duplicate|14**"),
+            ("@Human", -2, "@**Human Duplicate|13**"),
             ("@Human", -3, "@**Human 2**"),
             ("@Human", -4, "@**Human 1**"),
             ("@Human", -5, "@**Human Myself**"),
             ("@Human", -6, None),
             ("@_Human", 0, "@_**Human Myself**"),
             ("@_Human", 1, "@_**Human 1**"),
             ("@_Human", 2, "@_**Human 2**"),
-            ("@_Human", 3, "@_**Human Duplicate**"),
-            ("@_Human", 4, "@_**Human Duplicate**"),
+            ("@_Human", 3, "@_**Human Duplicate|13**"),
+            ("@_Human", 4, "@_**Human Duplicate|14**"),
             ("@H", 1, "@**Human 1**"),
             ("@Hu", 1, "@**Human 1**"),
             ("@Hum", 1, "@**Human 1**"),
@@ -260,8 +260,8 @@ def test_generic_autocomplete_set_footer(
             ("@", 0, "@**Human Myself**"),
             ("@", 1, "@**Human 1**"),
             ("@", 2, "@**Human 2**"),
-            ("@", 3, "@**Human Duplicate**"),
-            ("@", 4, "@**Human Duplicate**"),
+            ("@", 3, "@**Human Duplicate|13**"),
+            ("@", 4, "@**Human Duplicate|14**"),
             ("@", 5, "@*Group 1*"),
             ("@", 6, "@*Group 2*"),
             ("@", 7, "@*Group 3*"),
@@ -272,8 +272,8 @@ def test_generic_autocomplete_set_footer(
             ("@**", 0, "@**Human Myself**"),
             ("@**", 1, "@**Human 1**"),
             ("@**", 2, "@**Human 2**"),
-            ("@", 3, "@**Human Duplicate**"),
-            ("@", 4, "@**Human Duplicate**"),
+            ("@", 3, "@**Human Duplicate|13**"),
+            ("@", 4, "@**Human Duplicate|14**"),
             ("@**", 5, None),  # Reached last match
             ("@**", 6, None),  # Beyond end
             # Expected sequence of autocompletes from '@*' (only groups)
@@ -287,11 +287,11 @@ def test_generic_autocomplete_set_footer(
             ("@_", 0, "@_**Human Myself**"),  # NOTE: No silent group mention
             ("@_", 1, "@_**Human 1**"),
             ("@_", 2, "@_**Human 2**"),
-            ("@_", 3, "@_**Human Duplicate**"),
-            ("@_", 4, "@_**Human Duplicate**"),
+            ("@_", 3, "@_**Human Duplicate|13**"),
+            ("@_", 4, "@_**Human Duplicate|14**"),
             ("@_", 5, None),  # Reached last match
             ("@_", 6, None),  # Beyond end
-            ("@_", -1, "@_**Human Duplicate**"),
+            ("@_", -1, "@_**Human Duplicate|14**"),
             # Complex autocomplete prefixes.
             ("(@H", 0, "(@**Human Myself**"),
             ("(@H", 1, "(@**Human 1**"),
@@ -340,6 +340,41 @@ def test_generic_autocomplete_mentions_subscribers(
         typeahead_string = write_box.generic_autocomplete(text, state)
         assert typeahead_string == required_typeahead
 
+    @pytest.mark.parametrize(
+        "text, expected_distinct_prefix",
+        # Add 3 different lists of tuples, with each tuple containing a combination
+        # of the text to be autocompleted and the corresponding typeahead prefix to
+        # be added to the typeahead suggestions. Only the "@" case has to be ignored
+        # while building the parameters, because it includes group suggestions too.
+        [("@" + "Human"[: index + 1], "@") for index in range(len("Human"))]
+        + [("@**" + "Human"[:index], "@") for index in range(len("Human") + 1)]
+        + [("@_" + "Human"[:index], "@_") for index in range(len("Human") + 1)],
+    )
+    def test_generic_autocomplete_user_mentions(
+        self, write_box, mocker, text, expected_distinct_prefix, state=1
+    ):
+        _process_typeaheads = mocker.patch(BOXES + ".WriteBox._process_typeaheads")
+
+        write_box.generic_autocomplete(text, state)
+
+        matching_users = [
+            "Human Myself",
+            "Human 1",
+            "Human 2",
+            "Human Duplicate",
+            "Human Duplicate",
+        ]
+        distinct_matching_users = [
+            expected_distinct_prefix + "**Human Myself**",
+            expected_distinct_prefix + "**Human 1**",
+            expected_distinct_prefix + "**Human 2**",
+            expected_distinct_prefix + "**Human Duplicate|13**",
+            expected_distinct_prefix + "**Human Duplicate|14**",
+        ]
+        _process_typeaheads.assert_called_once_with(
+            distinct_matching_users, state, matching_users
+        )
+
     @pytest.mark.parametrize(
         "text, state, required_typeahead, to_pin",
         [

zulipterminal/ui_tools/boxes.py

@@ -1,7 +1,7 @@
 import re
 import typing
 import unicodedata
-from collections import OrderedDict, defaultdict
+from collections import Counter, OrderedDict, defaultdict
 from datetime import date, datetime, timedelta
 from sys import platform
 from time import sleep, time
@@ -457,12 +457,27 @@ def autocomplete_users(
         )
 
         user_names = [user["full_name"] for user in sorted_matching_users]
+
+        # Counter holds a count of each name in the list of users' names in a
+        # dict-like manner, which is a more efficient approach when compared to
+        # slicing the original list on each name.
+        # FIXME: Use a persistent counter rather than generate one on each autocomplete.
+        user_names_counter = Counter(user_names)
+
+        # Append user_id's to users with the same names.
+        user_names_with_distinct_duplicates = [
+            f"{user['full_name']}|{user['user_id']}"
+            if user_names_counter[user["full_name"]] > 1
+            else user["full_name"]
+            for user in sorted_matching_users
+        ]
+
         extra_prefix = "{}{}".format(
             "*" if prefix_string[-1] != "*" else "",
             "*" if prefix_string[-2:] != "**" else "",
         )
         user_typeahead = format_string(
-            user_names, prefix_string + extra_prefix + "{}**"
+            user_names_with_distinct_duplicates, prefix_string + extra_prefix + "{}**"
         )
 
         return user_typeahead, user_names