Added test case for recursive variadic template specialization

src/sequence_diagram/generators/plantuml/sequence_diagram_generator.cc

@@ -41,16 +41,21 @@ void generator::generate_call(const message &m, std::ostream &ostr) const
     const auto from = m_config.using_namespace().relative(m.from);
     const auto to = m_config.using_namespace().relative(m.to);
 
+    if (from.empty() || to.empty()) {
+        LOG_DBG("Skipping empty call from '{}' to '{}'", from, to);
+        return;
+    }
+
+    auto message = m.message;
+    if (!message.empty())
+        message += "()";
+
     ostr << '"' << from << "\" "
          << common::generators::plantuml::to_plantuml(message_t::kCall) << " \""
-         << to << "\" : " << m.message << "()" << std::endl;
+         << to << "\" : " << message << std::endl;
 
-    if (m.message == "add" && to == "A" && from == "A")
-        LOG_DBG("Generating call '{}' from {} [{}] to {} [{}]", m.message, from,
-            m.from_usr, to, m.to_usr);
-    else
-        LOG_DBG("Generating call '{}' from {} [{}] to {} [{}]", m.message, from,
-            m.from_usr, to, m.to_usr);
+    LOG_DBG("Generated call '{}' from {} [{}] to {} [{}]", message, from,
+        m.from_usr, to, m.to_usr);
 }
 
 void generator::generate_return(const message &m, std::ostream &ostr) const
@@ -71,11 +76,19 @@ void generator::generate_activity(const activity &a, std::ostream &ostr) const
 {
     for (const auto &m : a.messages) {
         const auto to = m_config.using_namespace().relative(m.to);
+
+        if (to.empty())
+            continue;
+
         generate_call(m, ostr);
+
         ostr << "activate " << '"' << to << '"' << std::endl;
+
         if (m_model.sequences.find(m.to_usr) != m_model.sequences.end())
             generate_activity(m_model.sequences[m.to_usr], ostr);
+
         generate_return(m, ostr);
+
         ostr << "deactivate " << '"' << to << '"' << std::endl;
     }
 }