Use unread data in topic_data.get_recent_names().

Fixes #9347.

frontend_tests/node_tests/general.js

@@ -96,6 +96,7 @@ composebox_typeahead.add_topic = noop;
 
 // We can also bring in real code:
 zrequire('recent_senders');
+zrequire('unread');
 zrequire('topic_data');
 
 // And finally require the module that we will test directly:
@@ -124,7 +125,6 @@ run_test('message_store', () => {
 
 // Tracking unread messages is a very fundamental part of the Zulip
 // app, and we use the unread object to track unread messages.
-zrequire('unread');
 
 run_test('unread', () => {
     const stream_id = denmark_stream.stream_id;

frontend_tests/node_tests/search_suggestion.js

@@ -6,6 +6,7 @@ zrequire('narrow_state');
 zrequire('stream_data');
 zrequire('topic_data');
 zrequire('people');
+zrequire('unread');
 var search = zrequire('search_suggestion');
 
 var bob = {

frontend_tests/node_tests/topic_data.js

@@ -1,3 +1,4 @@
+zrequire('unread');
 zrequire('topic_data');
 
 set_global('channel', {});
@@ -126,7 +127,42 @@ run_test('server_history', () => {
     assert.deepEqual(history, ['hist2', 'hist1', 'hist3']);
 });
 
+(function test_unread_logic() {
+    var stream_id = 77;
 
+    topic_data.add_message({
+        stream_id: stream_id,
+        message_id: 201,
+        topic_name: 'toPic1',
+    });
+
+    topic_data.add_message({
+        stream_id: stream_id,
+        message_id: 45,
+        topic_name: 'topic2',
+    });
+
+    var history = topic_data.get_recent_names(stream_id);
+    assert.deepEqual(history, ['toPic1', 'topic2']);
+
+    const msgs = [
+        { id: 150, subject: 'TOPIC2' }, // will be ignored
+        { id: 61, subject: 'unread1' },
+        { id: 60, subject: 'unread1' },
+        { id: 20, subject: 'UNREAD2' },
+    ];
+
+    _.each(msgs, (msg) => {
+        msg.type = 'stream';
+        msg.stream_id = stream_id;
+        msg.unread = true;
+    });
+
+    unread.process_loaded_messages(msgs);
+
+    history = topic_data.get_recent_names(stream_id);
+    assert.deepEqual(history, ['toPic1', 'unread1', 'topic2', 'UNREAD2']);
+}());
 
 run_test('server_history_end_to_end', () => {
     topic_data.reset();

frontend_tests/node_tests/topic_list.js

@@ -11,6 +11,7 @@ set_global('templates', {});
 zrequire('hash_util');
 zrequire('narrow');
 zrequire('stream_data');
+zrequire('unread');
 zrequire('topic_data');
 zrequire('topic_list');
 

static/js/topic_data.js

@@ -8,7 +8,7 @@ exports.stream_has_topics = function (stream_id) {
     return stream_dict.has(stream_id);
 };
 
-exports.topic_history = function () {
+exports.topic_history = function (stream_id) {
     var topics = new Dict({fold_case: true});
 
     var self = {};
@@ -95,7 +95,14 @@ exports.topic_history = function () {
     };
 
     self.get_recent_names = function () {
-        var recents = topics.values();
+        var my_recents = topics.values();
+
+        var missing_topics = unread.get_missing_topics({
+            stream_id: stream_id,
+            topic_dict: topics,
+        });
+
+        var recents = my_recents.concat(missing_topics);
 
         recents.sort(function (a, b) {
             return b.message_id - a.message_id;
@@ -131,7 +138,7 @@ exports.find_or_create = function (stream_id) {
     var history = stream_dict.get(stream_id);
 
     if (!history) {
-        history = exports.topic_history();
+        history = exports.topic_history(stream_id);
         stream_dict.set(stream_id, history);
     }
 
@@ -171,11 +178,7 @@ exports.get_server_history = function (stream_id, on_success) {
 };
 
 exports.get_recent_names = function (stream_id) {
-    var history = stream_dict.get(stream_id);
+    var history = exports.find_or_create(stream_id);
-
-    if (!history) {
-        return [];
-    }
 
     return history.get_recent_names();
 };