js: Convert static/js/scroll_util.js to ES6 module.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

.eslintrc.json

@@ -212,7 +212,6 @@
                 "resize": false,
                 "rows": false,
                 "scroll_bar": false,
-                "scroll_util": false,
                 "search": false,
                 "search_pill_widget": false,
                 "search_suggestion": false,

frontend_tests/node_tests/activity.js

@@ -42,6 +42,7 @@ const _keydown_util = {
 const compose_state = {};
 
 const _scroll_util = {
+    __esModule: true,
     scroll_element_into_container: () => {},
 };
 
@@ -74,7 +75,7 @@ rewiremock("../../static/js/keydown_util").with(_keydown_util);
 set_global("pm_list", _pm_list);
 set_global("popovers", _popovers);
 set_global("resize", _resize);
-set_global("scroll_util", _scroll_util);
+rewiremock("../../static/js/scroll_util").with(_scroll_util);
 set_global("stream_popover", _stream_popover);
 set_global("ui", _ui);
 set_global("server_events", {

frontend_tests/node_tests/dropdown_list_widget.js

@@ -13,7 +13,6 @@ const _ListWidget = {
 set_global("ListWidget", _ListWidget);
 
 const dropdown_list_widget = zrequire("dropdown_list_widget");
-zrequire("scroll_util");
 
 const setup_zjquery_data = (name) => {
     const input_group = $(".input_group");

frontend_tests/node_tests/stream_list.js

@@ -394,7 +394,7 @@ test_ui("narrowing", () => {
     topic_list.rebuild = noop;
     topic_list.active_stream_id = noop;
     topic_list.get_stream_li = noop;
-    scroll_util.scroll_element_into_container = noop;
+    scroll_util.__Rewire__("scroll_element_into_container", noop);
 
     set_global("ui", {
         get_scroll_element: (element) => element,

static/js/bundles/app.js

@@ -15,7 +15,6 @@ import "flatpickr/dist/plugins/confirmDate/confirmDate";
 // Import app JS
 import "../i18n";
 import "../fold_dict";
-import "../scroll_util";
 import "../drafts";
 import "../input_pill";
 import "../user_pill";

static/js/global.d.ts

@@ -85,7 +85,6 @@ declare let reminder: any;
 declare let resize: any;
 declare let rows: any;
 declare let scroll_bar: any;
-declare let scroll_util: any;
 declare let search: any;
 declare let search_pill_widget: any;
 declare let search_suggestion: any;

static/js/list_cursor.js

@@ -1,3 +1,5 @@
+import * as scroll_util from "./scroll_util";
+
 export class ListCursor {
     constructor({highlight_class, list}) {
         const config_ok =

static/js/scroll_util.js

@@ -1,6 +1,4 @@
-"use strict";
+export function scroll_delta(opts) {
-
-exports.scroll_delta = function (opts) {
     const elem_top = opts.elem_top;
     const container_height = opts.container_height;
     const elem_bottom = opts.elem_bottom;
@@ -18,9 +16,9 @@ exports.scroll_delta = function (opts) {
     }
 
     return delta;
-};
+}
 
-exports.scroll_element_into_container = function (elem, container) {
+export function scroll_element_into_container(elem, container) {
     // This does the minimum amount of scrolling that is needed to make
     // the element visible.  It doesn't try to center the element, so
     // this will be non-intrusive to users when they already have
@@ -36,13 +34,11 @@ exports.scroll_element_into_container = function (elem, container) {
         container_height: container.height(),
     };
 
-    const delta = exports.scroll_delta(opts);
+    const delta = scroll_delta(opts);
 
     if (delta === 0) {
         return;
     }
 
     container.scrollTop(container.scrollTop() + delta);
-};
+}
-
-window.scroll_util = exports;

static/js/stream_list.js

@@ -7,6 +7,7 @@ const render_stream_sidebar_row = require("../templates/stream_sidebar_row.hbs")
 
 const keydown_util = require("./keydown_util");
 const {ListCursor} = require("./list_cursor");
+const scroll_util = require("./scroll_util");
 const stream_sort = require("./stream_sort");
 const topic_zoom = require("./topic_zoom");
 

static/js/subs.js

@@ -10,6 +10,7 @@ const render_subscriptions = require("../templates/subscriptions.hbs");
 const components = require("./components");
 const loading = require("./loading");
 const people = require("./people");
+const scroll_util = require("./scroll_util");
 const search_util = require("./search_util");
 const stream_create = require("./stream_create");
 const stream_ui_updates = require("./stream_ui_updates");