fix(template): allow whitespace in extends children

Author: GaspardKirira

src/Renderer.cpp

@@ -26,6 +26,8 @@
 #include <cstdlib>
 #include <utility>
 #include <variant>
+#include <cctype>
+#include <string_view>
 
 namespace vix::template_
 {
@@ -61,6 +63,19 @@ namespace vix::template_
       return true;
     }
 
+    [[nodiscard]] bool is_whitespace_only(std::string_view text) noexcept
+    {
+      for (const unsigned char c : text)
+      {
+        if (!std::isspace(c))
+        {
+          return false;
+        }
+      }
+
+      return true;
+    }
+
     [[nodiscard]] bool is_floating_literal(const std::string &value) noexcept
     {
       if (value.empty())
@@ -848,6 +863,15 @@ namespace vix::template_
         continue;
       }
 
+      if (child->type() == NodeType::Text)
+      {
+        const auto &text = static_cast<const TextNode &>(*child);
+        if (is_whitespace_only(text.value()))
+        {
+          continue;
+        }
+      }
+
       if (child->type() != NodeType::Block)
       {
         throw RendererError(