ensure the first flag reason is always selected & that the flag can be sent with kbd only

Author: Oaphi

app/views/posts/_flag_modal.html.erb

@@ -6,7 +6,7 @@
       user : User that will flag the post
 "%>
 
-<div class="post--action-dialog js-flag-box">
+<%= form_tag new_flag_path, method: :post, class: 'post--action-dialog js-flag-box' do %>
   <div class="widget">
     <div class="widget--header">Why does this post require attention from curators or moderators?</div>
     <% if user&.active_flags_on?(post) %>
@@ -27,7 +27,7 @@
       </div>
     <% end %>
     <% unless post.locked? %>
-      <% PostFlagType.where(post_type_id: [post.post_type.id, nil]).where(active: 1).each do |reason| %>
+      <% PostFlagType.where(post_type_id: [post.post_type.id, nil]).where(active: 1).each_with_index do |reason, idx| %>
         <div class="widget--body">
           <div class="grid">
             <div class="grid--cell">
@@ -36,6 +36,7 @@
                      name="flag-reason"
                      value="<%= reason.id %>"
                      id="flag-reason-<%= reason.id %>_<%= post.id  %>"
+                     <%= 'checked' if idx.zero? %>
                      data-requires-details="<%= reason.requires_details %>"
                      data-response-type="<%= reason.name == "needs author's attention" ? 'comment' : nil %>" />
             </div>
@@ -109,10 +110,10 @@
     </div>
     <div class="widget--footer">
       <button class="flag-link button is-filled is-muted"
-                      data-post-type="<%= post.question? ? 'Question' : 'Answer' %>"
-                      data-post-id="<%= post.id %>">
+              data-post-type="<%= post.question? ? 'Question' : 'Answer' %>"
+              data-post-id="<%= post.id %>">
         Flag for attention
       </button>
     </div>
   </div>
-</div>
+<% end %>