add js function AddComment and system test for function

app/assets/javascripts/comment.js

@@ -51,3 +51,15 @@ function insertTitleSuggestionTemplate() {
   var newText = currentText+template;
   element.val(newText);
 }
+
+// JS API for submitting comments
+function addComment(comment, selector) {
+  selector = selector || '.comment-form'; // class instead of id because of the bound function on line 3
+  $.ajax({
+    url: $(selector).attr('action'), // grab the URL from the form itself
+    data: { body: comment },
+    success: (event, success) => {
+      $(selector).trigger('ajax:success', event);
+    }
+  });
+}

app/views/notes/_comment.html.erb

@@ -127,7 +127,9 @@
   <div style="border: 1px solid #e7e7e7;padding: 18px;" id="c<%= comment.cid %>show">
 
     <% comment_body = comment.render_body %>
-    <p class="comment-body" id="comment-body-<%= comment.cid %>"><%= raw insert_extras(filtered_comment_body(comment_body)) %></p>
+    <div class="comment-body" id="comment-body-<%= comment.cid %>">
+      <%= raw insert_extras(filtered_comment_body(comment_body)) %>
+    </div>
 
     <% if contain_trimmed_body?(comment_body) %>
       <span style="background-color: #DCDCDC;  border-radius: 7px; cursor: pointer;" ><a class="email-toggle" data-toggle="collapse" data-target="#comment-<%= comment.cid %>-extra-content" style='text-decoration: none;'>&nbsp;&ensp;&#x2022&#x2022&#x2022&nbsp;&ensp;</a></span>

test/system/comment_test.rb

@@ -0,0 +1,26 @@
+require 'test_helper'
+require "application_system_test_case"
+# https://guides.rubyonrails.org/testing.html#implementing-a-system-test
+
+class CommentTest < ApplicationSystemTestCase
+  Capybara.default_max_wait_time = 60
+
+  test 'adding a tag via javascript' do
+    visit '/'
+
+    click_on 'Login'
+
+    fill_in("username-login", with: "jeff")
+    fill_in("password-signup", with: "secretive")
+    click_on "Log in"
+
+    visit "/wiki/wiki-page-path/comments"
+
+    # run the javascript function
+    page.evaluate_script("addComment('fantastic four')")
+
+    # check that the tag showed up on the page
+    assert_selector('#comments-list .comment-body p', text: 'fantastic four')
+  end
+
+end