refactor: Change where we initialize scrolling code.

This is a more sensible place to initialize the
the scrolling handler, plus it breaks an annoying
indirect dependency on jQuery for the unit tests.

Author: showell

frontend_tests/node_tests/stream_data.js

@@ -4,7 +4,7 @@ const {strict: assert} = require("assert");
 
 const _ = require("lodash");
 
-const {set_global, stub_out_jquery, zrequire} = require("../zjsunit/namespace");
+const {set_global, zrequire} = require("../zjsunit/namespace");
 const {run_test} = require("../zjsunit/test");
 
 set_global("page_params", {
@@ -13,9 +13,6 @@ set_global("page_params", {
     is_guest: false,
 });
 
-set_global("document", null);
-stub_out_jquery();
-
 zrequire("color_data");
 zrequire("hash_util");
 zrequire("stream_topic_history");

static/js/message_list.js

@@ -415,12 +415,4 @@ exports.all = new MessageList({
     muting_enabled: false,
 });
 
-// We stop autoscrolling when the user is clearly in the middle of
-// doing something.  Be careful, though, if you try to capture
-// mousemove, then you will have to contend with the autoscroll
-// itself generating mousemove events.
-$(document).on("message_selected.zulip wheel", () => {
-    message_viewport.stop_auto_scrolling();
-});
-
 window.message_list = exports;

static/js/message_viewport.js

@@ -457,6 +457,14 @@ exports.initialize = function () {
     $(document).on("compose_started compose_canceled compose_finished", () => {
         bottom_of_feed.reset();
     });
+
+    // We stop autoscrolling when the user is clearly in the middle of
+    // doing something.  Be careful, though, if you try to capture
+    // mousemove, then you will have to contend with the autoscroll
+    // itself generating mousemove events.
+    $(document).on("message_selected.zulip wheel", () => {
+        exports.stop_auto_scrolling();
+    });
 };
 
 window.message_viewport = exports;