messagebox: Add classnames to mark which messages contain which mentions.

This is part of redesigning messages (#22059). This commit adds
classnames to messages with mentions, differentiating direct mentions
from wildcard mentions from usergroup mentions, and this set us up
for a future commit where we'll have those different kinds of messages
be displayed in different colors.

frontend_tests/node_tests/message_list_view.js

@@ -6,6 +6,7 @@ const _ = require("lodash");
 
 const {mock_esm, set_global, zrequire} = require("../zjsunit/namespace");
 const {run_test} = require("../zjsunit/test");
+const $ = require("../zjsunit/zjquery");
 
 set_global("document", "document-stub");
 
@@ -309,11 +310,26 @@ test("muted_message_vars", () => {
     }
 
     (function test_hidden_message_variables() {
+        // We want to have no search results, which apparently works like this.
+        // See https://chat.zulip.org/#narrow/stream/6-frontend/topic/set_find_results.20with.20no.20results/near/1414799
+        const empty_list_stub = $.create("empty-stub", {children: []});
+        $("<message-stub-1>").set_find_results(".user-mention:not(.silent)", empty_list_stub);
+        $("<message-stub2>").set_find_results(".user-mention:not(.silent)", empty_list_stub);
+        $("<message-stub-3>").set_find_results(".user-mention:not(.silent)", empty_list_stub);
         // Make a representative message group of three messages.
         const messages = [
-            build_message_context({sender_id: 10}, {include_sender: true}),
+            build_message_context(
-            build_message_context({mentioned: true, sender_id: 10}, {include_sender: false}),
+                {sender_id: 10, content: "<message-stub-1>"},
-            build_message_context({sender_id: 10}, {include_sender: false}),
+                {include_sender: true},
+            ),
+            build_message_context(
+                {mentioned: true, sender_id: 10, content: "<message-stub2>"},
+                {include_sender: false},
+            ),
+            build_message_context(
+                {sender_id: 10, content: "<message-stub-3>"},
+                {include_sender: false},
+            ),
         ];
         const message_group = build_message_group(messages);
         const list = build_list([message_group]);
@@ -336,8 +352,8 @@ test("muted_message_vars", () => {
         assert.equal(result[1].include_sender, false);
         assert.equal(result[2].include_sender, false);
 
-        // Additionally test that, `contains_mention` is true on that message has a mention.
+        // Additionally test that the message with a mention is marked as such.
-        assert.equal(result[1].contains_mention, true);
+        assert.equal(result[1].mention_classname, "group_mention");
 
         // Now, mute the sender.
         muted_users.add_muted_user(10);
@@ -352,8 +368,9 @@ test("muted_message_vars", () => {
         assert.equal(result[1].include_sender, false);
         assert.equal(result[2].include_sender, false);
 
-        // Additionally test that, `contains_mention` is false even on that message which has a mention.
+        // Additionally test that, both there is no mention classname even on that message
-        assert.equal(result[1].contains_mention, false);
+        // which has a mention, since we don't want to display muted mentions so visibly.
+        assert.equal(result[1].mention_classname, null);
 
         // Now, reveal the hidden messages.
         let is_revealed = true;
@@ -368,8 +385,8 @@ test("muted_message_vars", () => {
         assert.equal(result[1].include_sender, true);
         assert.equal(result[2].include_sender, true);
 
-        // Additionally test that, `contains_mention` is true on that message which has a mention.
+        // Additionally test that the message with a mention is marked as such.
-        assert.equal(result[1].contains_mention, true);
+        assert.equal(result[1].mention_classname, "group_mention");
 
         // Now test rehiding muted user's message
         is_revealed = false;
@@ -384,8 +401,9 @@ test("muted_message_vars", () => {
         assert.equal(result[1].include_sender, false);
         assert.equal(result[2].include_sender, false);
 
-        // Additionally test that, `contains_mention` is false on that message which has a mention.
+        // Additionally test that, both there is no mention classname even on that message
-        assert.equal(result[1].contains_mention, false);
+        // which has a mention, since we don't want to display hidden mentions so visibly.
+        assert.equal(result[1].mention_classname, null);
     })();
 });
 

static/js/message_list_view.js

@@ -326,8 +326,36 @@ export class MessageListView {
 
         message_container.is_hidden = is_hidden;
         // Make sure the right thing happens if the message was edited to mention us.
-        message_container.contains_mention = message_container.msg.mentioned && !is_hidden;
+        if (!is_hidden && message_container.msg.mentioned) {
+            // Currently the API does not differentiate between a group mention and
+            // a user mention. For now, we parse the markdown to see if the message
+            // mentions the user.
+            let is_user_mention = false;
+            const $msg = $(message_container.msg.content);
+            $msg.find(".user-mention:not(.silent)").each(function () {
+                const user_id = rendered_markdown.get_user_id_for_mention_button(this);
+                if (user_id === "*") {
+                    return;
+                }
+                if (people.is_my_user_id(user_id)) {
+                    is_user_mention = true;
+                }
+            });
 
+            // If a message includes a user mention, then we don't care if there is a
+            // group/wildcard mention, and color the message as a user mention. If the
+            // message didn't include a user mention, then it was a usergroup/wildcard
+            // mention (which is the only other option for `mentioned` being true).
+            if (message_container.msg.mentioned_me_directly && is_user_mention) {
+                message_container.mention_classname = "direct_mention";
+            } else {
+                message_container.mention_classname = "group_mention";
+            }
+        } else {
+            // If there are no mentions, the classname might need to be updated (i.e.
+            // removed) to reflect this.
+            message_container.mention_classname = null;
+        }
         message_container.include_sender = message_container.include_sender && !is_hidden;
         if (is_revealed) {
             // If the message is to be revealed, we show the sender anyways, because the

static/js/rendered_markdown.js

@@ -27,7 +27,7 @@ import {user_settings} from "./user_settings";
     is being displayed.
 */
 
-function get_user_id_for_mention_button(elem) {
+export function get_user_id_for_mention_button(elem) {
     const user_id_string = $(elem).attr("data-user-id");
     // Handle legacy Markdown that was rendered before we cut
     // over to using data-user-id.

static/templates/single_message.hbs

@@ -1,5 +1,5 @@
 <div zid="{{msg/id}}" id="{{table_name}}{{msg/id}}"
-  class="message_row{{^msg/is_stream}} private-message{{/msg/is_stream}}{{#include_sender}} include-sender{{/include_sender}}{{#contains_mention}} mention{{/contains_mention}}{{#include_footer}} last_message{{/include_footer}}{{#msg.unread}} unread{{/msg.unread}} {{#if msg.locally_echoed}}local{{/if}} selectable_row"
+  class="message_row{{^msg/is_stream}} private-message{{/msg/is_stream}}{{#include_sender}} include-sender{{/include_sender}}{{#if mention_classname}} {{mention_classname}}{{/if}}{{#include_footer}} last_message{{/include_footer}}{{#msg.unread}} unread{{/msg.unread}} {{#if msg.locally_echoed}}local{{/if}} selectable_row"
   role="listitem">
     <div class="unread_marker"><div class="unread-marker-fill"></div></div>
     {{#if want_date_divider}}