js: Convert _.find(a, …) to a.find(…).

And convert the corresponding function expressions to arrow style
while we’re here.

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

static/js/components.js

@@ -98,9 +98,7 @@ exports.toggle = function (opts) {
         maybe_go_right: maybe_go_right,
 
         disable_tab: function (name) {
-            const value = _.find(opts.values, function (o) {
+            const value = opts.values.find(o => o.key === name);
-                return o.key === name;
-            });
 
             const idx = opts.values.indexOf(value);
             meta.$ind_tab.eq(idx).addClass('disabled');
@@ -118,9 +116,7 @@ exports.toggle = function (opts) {
         // go through the process of finding the correct tab for a given name,
         // and when found, select that one and provide the proper callback.
         goto: function (name) {
-            const value = _.find(opts.values, function (o) {
+            const value = opts.values.find(o => o.label === name || o.key === name);
-                return o.label === name || o.key === name;
-            });
 
             const idx = opts.values.indexOf(value);
 

static/js/emoji_picker.js

@@ -254,9 +254,9 @@ function get_alias_to_be_used(message_id, emoji_name) {
         }
     }
     const user_id = page_params.user_id;
-    const reaction = _.find(message.reactions, function (reaction) {
+    const reaction = message.reactions.find(
-        return reaction.user.id === user_id && aliases.includes(reaction.emoji_name);
+        reaction => reaction.user.id === user_id && aliases.includes(reaction.emoji_name)
-    });
+    );
     if (reaction) {
         return reaction.emoji_name;
     }
@@ -729,7 +729,7 @@ exports.register_click_handlers = function () {
     $("body").on("click", ".emoji-popover-tab-item", function (e) {
         e.stopPropagation();
         e.preventDefault();
-        const offset = _.find(section_head_offsets, function (o) {
+        const offset = section_head_offsets.find(function (o) {
             return o.section === $(this).attr("data-tab-name");
         }.bind(this));
 

static/js/filter.js

@@ -530,7 +530,7 @@ Filter.prototype = {
     first_valid_id_from: function (msg_ids) {
         const predicate = this.predicate();
 
-        const first_id = _.find(msg_ids, function (msg_id) {
+        const first_id = msg_ids.find(msg_id => {
             const message = message_store.get(msg_id);
 
             if (message === undefined) {

static/js/input_pill.js

@@ -219,9 +219,7 @@ exports.create = function (opts) {
         },
 
         getByID: function (id) {
-            return _.find(store.pills, function (pill) {
+            return store.pills.find(pill => pill.id === id);
-                return pill.id === id;
-            });
         },
 
         items: function () {

static/js/markdown.js

@@ -40,14 +40,12 @@ exports.set_name_in_mention_element = function (element, name) {
 exports.contains_backend_only_syntax = function (content) {
     // Try to guess whether or not a message has bugdown in it
     // If it doesn't, we can immediately render it client-side
-    const markedup = _.find(backend_only_markdown_re, function (re) {
+    const markedup = backend_only_markdown_re.find(re => re.test(content));
-        return re.test(content);
-    });
 
     // If a realm filter doesn't start with some specified characters
     // then don't render it locally. It is workaround for the fact that
     // javascript regex doesn't support lookbehind.
-    const false_filter_match = _.find(realm_filter_list, function (re) {
+    const false_filter_match = realm_filter_list.find(re => {
         const pattern = /(?:[^\s'"\(,:<])/.source + re[0].source + /(?![\w])/.source;
         const regex = new RegExp(pattern);
         return regex.test(content);

static/js/message_list_data.js

@@ -180,9 +180,7 @@ MessageListData.prototype = {
     },
 
     first_unread_message_id: function () {
-        const first_unread = _.find(this._items, function (message) {
+        const first_unread = this._items.find(message => unread.message_unread(message));
-            return unread.message_unread(message);
-        });
 
         if (first_unread) {
             return first_unread.id;

static/js/message_list_view.js

@@ -1156,12 +1156,12 @@ MessageListView.prototype = {
         // groups are merged etc.) , but we only call this from flows
         // like message editing, so it's not a big performance
         // problem.
-        return _.find(this._message_groups, function (message_group) {
+        return this._message_groups.find(
             // Since we don't have a way to get a message group from
             // the containing message container, we just do a search
             // to find it.
-            return message_group.message_group_id === message_group_id;
+            message_group => message_group.message_group_id === message_group_id
-        });
+        );
     },
 
     _rerender_header: function (message_containers) {

static/js/settings_bots.js

@@ -64,9 +64,7 @@ function is_local_part(value, element) {
 }
 
 exports.type_id_to_string = function (type_id) {
-    const name = _.find(page_params.bot_types, function (bot_type) {
+    const name = page_params.bot_types.find(bot_type => bot_type.type_id === type_id).name;
-        return bot_type.type_id === type_id;
-    }).name;
     return i18n.t(name);
 };
 

static/js/submessage.js

@@ -90,9 +90,7 @@ exports.update_message = function (submsg) {
         message.submessages = [];
     }
 
-    const existing = _.find(message.submessages, function (sm) {
+    const existing = message.submessages.find(sm => sm.id === submsg.id);
-        return sm.id === submsg.id;
-    });
 
     if (existing !== undefined) {
         blueslip.warn("Got submessage multiple times: " + submsg.id);