From 1054d63820000eaffe6fba5d322a7f63d7199ae0 Mon Sep 17 00:00:00 2001
From: Tim Abbott <tabbott@zulipchat.com>
Date: Wed, 12 Dec 2018 16:13:29 -0800
Subject: [PATCH] message_fetch: Deduplicate logic for finish_newer_batch.

Like the other similar commits, we were doing the same work in all
code paths, just with a much more error-prone approach.

We can also now remove the now-unused finish_initial_narrow function.
---
 frontend_tests/node_tests/fetch_status.js |  4 +--
 static/js/fetch_status.js                 |  5 ----
 static/js/message_fetch.js                | 35 ++++++++---------------
 3 files changed, 14 insertions(+), 30 deletions(-)

diff --git a/frontend_tests/node_tests/fetch_status.js b/frontend_tests/node_tests/fetch_status.js
index 0168a7897a..2281e9f748 100644
--- a/frontend_tests/node_tests/fetch_status.js
+++ b/frontend_tests/node_tests/fetch_status.js
@@ -54,7 +54,7 @@ run_test('basics', () => {
         found_newest: true,
         history_limited: true,
     };
-    fetch_status.finish_initial_narrow(data);
+    fetch_status.finish_newer_batch(data);
     fetch_status.finish_older_batch(data);
 
     has_found_newest();
@@ -76,7 +76,7 @@ run_test('basics', () => {
         found_newest: false,
         history_limited: false,
     };
-    fetch_status.finish_initial_narrow(data);
+    fetch_status.finish_newer_batch(data);
     fetch_status.finish_older_batch(data);
 
     can_load_older();
diff --git a/static/js/fetch_status.js b/static/js/fetch_status.js
index b2f1bbaa96..7546c25740 100644
--- a/static/js/fetch_status.js
+++ b/static/js/fetch_status.js
@@ -8,11 +8,6 @@ var FetchStatus = function () {
     var found_newest = false;
     var history_limited = false;
 
-    self.finish_initial_narrow = function (opts) {
-        loading_newer = false;
-        found_newest = opts.found_newest;
-    };
-
     self.start_older_batch = function () {
         loading_older = true;
     };
diff --git a/static/js/message_fetch.js b/static/js/message_fetch.js
index e32e83b91c..cb35ee8294 100644
--- a/static/js/message_fetch.js
+++ b/static/js/message_fetch.js
@@ -74,6 +74,17 @@ function get_messages_success(data, opts) {
         }
     }
 
+    if (opts.num_after > 0) {
+        opts.msg_list.fetch_status.finish_newer_batch({
+            found_newest: data.found_newest,
+        });
+        if (opts.msg_list === home_msg_list) {
+            message_list.all.fetch_status.finish_newer_batch({
+                found_newest: data.found_newest,
+            });
+        }
+    }
+
     if (opts.msg_list.narrowed && opts.msg_list !== current_msg_list) {
         // We unnarrowed before receiving new messages so
         // don't bother processing the newly arrived messages.
@@ -172,11 +183,7 @@ exports.load_messages_for_narrow = function (opts) {
         num_after: consts.narrow_after,
         msg_list: msg_list,
         use_first_unread_anchor: opts.use_first_unread_anchor,
-        cont: function (data) {
-            msg_list.fetch_status.finish_initial_narrow({
-                found_oldest: data.found_oldest,
-                found_newest: data.found_newest,
-            });
+        cont: function () {
             message_scroll.hide_indicators();
             opts.cont();
         },
@@ -269,16 +276,6 @@ exports.maybe_load_newer_messages = function (opts) {
         num_before: 0,
         num_after: consts.forward_batch_size,
         msg_list: msg_list,
-        cont: function (data) {
-            msg_list.fetch_status.finish_newer_batch({
-                found_newest: data.found_newest,
-            });
-            if (msg_list === home_msg_list) {
-                message_list.all.fetch_status.finish_newer_batch({
-                    found_newest: data.found_newest,
-                });
-            }
-        },
     });
 };
 
@@ -307,14 +304,6 @@ exports.initialize = function () {
                                      target_scroll_offset: page_params.initial_offset});
         }
 
-        home_msg_list.fetch_status.finish_newer_batch({
-            found_newest: data.found_newest,
-        });
-
-        message_list.all.fetch_status.finish_newer_batch({
-            found_newest: data.found_newest,
-        });
-
         if (data.found_newest) {
             server_events.home_view_loaded();
             exports.start_backfilling_messages();