left-sidebar: Use -, _, :, and / as additional topic word separators.

Previously, only spaces were used as word separators when searching
for topics. This meant that searching for "support" would not find a
topic named "topic_support" or "topic/support," which could lead to
unexpected results.

To address this, hyphen (-), underscore (_), colon (:), and slash (/)
have been added as additional word separators for topic filtering in
the left sidebar, as these characters are commonly used as separators
in topic names.

Fixes: #31844

web/src/topic_list_data.ts

@@ -187,7 +187,13 @@ export function get_list_info(
     }
 
     if (zoomed) {
-        topic_names = util.filter_by_word_prefix_match(topic_names, search_term, (item) => item);
+        const word_separator_regex = /[\s/:_-]/; // Use -, _, :, / as word separators in addition to spaces.
+        topic_names = util.filter_by_word_prefix_match(
+            topic_names,
+            search_term,
+            (topic) => topic,
+            word_separator_regex,
+        );
     }
 
     if (stream_muted && !zoomed) {

web/tests/topic_list_data.test.js

@@ -404,3 +404,41 @@ test("get_list_info unreads", ({override}) => {
         ],
     );
 });
+
+test("get_list_info with specific topics and searches", () => {
+    let list_info;
+
+    function add_topic_message(topic_name, message_id) {
+        stream_topic_history.add_message({
+            stream_id: general.stream_id,
+            topic_name,
+            message_id,
+        });
+    }
+
+    add_topic_message("BF-2924 zulip", 1001);
+    add_topic_message("tech_support/escalation", 1002);
+
+    list_info = get_list_info(true, "2924");
+    assert.equal(list_info.items.length, 1);
+    assert.equal(list_info.items[0].topic_name, "BF-2924 zulip");
+
+    list_info = get_list_info(true, "support/escalation");
+    assert.equal(list_info.items.length, 1);
+    assert.equal(list_info.items[0].topic_name, "tech_support/escalation");
+
+    list_info = get_list_info(true, "support");
+    assert.equal(list_info.items.length, 1);
+    assert.equal(list_info.items[0].topic_name, "tech_support/escalation");
+
+    list_info = get_list_info(true, "zulip");
+    assert.equal(list_info.items.length, 1);
+    assert.equal(list_info.items[0].topic_name, "BF-2924 zulip");
+
+    list_info = get_list_info(true, "SUPPORT");
+    assert.equal(list_info.items.length, 1);
+    assert.equal(list_info.items[0].topic_name, "tech_support/escalation");
+
+    list_info = get_list_info(true, "nonexistent");
+    assert.equal(list_info.items.length, 0);
+});