Add test code for MSC2184 - <details> tags

Author: ananace

config.yml.example

@@ -28,6 +28,7 @@ rules:
   # The following values are optional:
   #image: true           # Attach image to the notification?
   #embed_image: true     # Upload and embed the image into the message?
+  #details_tag: false    # Use a <details> tag to include image (MSC2184)
   #templates:
     # Templates to use when rendering the notification, available placeholders:
     #   %TEMPLATES% - lib/grafana_matrix/templates

lib/grafana_matrix/config.rb

@@ -49,6 +49,10 @@ def embed_image?
         data.fetch(:embed_image, true)
       end
 
+      def details?
+        data.fetch(:details_tag, false)
+      end
+
       def msgtype
         data.fetch(:msgtype, config.default_msgtype)
       end

lib/grafana_matrix/templates/html.erb

@@ -1,6 +1,13 @@
 <h4><a href="<%= data['ruleUrl'] %>" style="font-weight: bold; font-style: italic"><font color="<%= SEVERITY_COLOURS[data['state'].to_sym] %>"><%= data['title'] %></font></a></h4>
-<%- unless data.fetch('message', '').empty? -%>
+<%- if data['imageUrl'] && rule.details? && data['state'] != 'ok' -%>
+<details><summary>
+<%-   unless data.fetch('message', '').empty? -%>
+<%= data['message'] %>
+<%-   end -%>
+<%- else -%>
+<%-   unless data.fetch('message', '').empty? -%>
 <p><%= data['message'] %></p>
+<%-   end -%>
 <%- end -%>
 <%- if data.key? 'error' -%>
 <h5>Error:</h5>
@@ -12,12 +19,20 @@
 <b><%= match['metric'] %></b>: <%= match['value'] %><br/>
 <%-     end -%>
 <%-   end -%>
+<%-   if data['imageUrl'] && rule.details? -%>
+</summary>
+<%-   end -%>
 <%-   if data['imageUrl'] && rule.image? -%>
+<%-     if !rule.details? -%>
 <br/>
+<%-     end -%>
 <%-     if rule.embed_image? -%>
 <a href="<%= data['ruleUrl'] %>"><img src="<%= data['imageUrl'] %>" alt="<%= data['ruleName'] %>" /></a>
 <%-     else -%>
 <a href="<%= data['imageUrl'] %>">Alert image</a>
 <%-     end -%>
 <%-   end -%>
 <%- end -%>
+<%- if data['imageUrl'] && rule.details? -%>
+</details>
+<%- end -%>