extracted to a function the casting of the

different types to make tests cleaner

test/parser/utils.hpp

@@ -1,9 +1,45 @@
+#include "ast/ast.hpp"
 #include "lexer/lexer.hpp"
 #include "parser/parser.hpp"
 
+#include <doctest.h>
 #include <sstream>
 
-void check_parser_errors(const std::vector<ast::error::error*>& errors);
+void check_parser_errors(const std::vector<ast::error::error*>&);
+
+namespace {
+    template <typename T, typename Base>
+    T* cast_impl(Base* base) {
+        static_assert(
+            std::is_base_of_v<Base, T>,
+            "T must be derived from Base"
+        );
+
+        T* t;
+        REQUIRE_NOTHROW(t = dynamic_cast<T*>(base));
+        REQUIRE_MESSAGE(
+            t != nullptr,
+            "Couldn't cast expression to a " * std::string(typeid(T).name())
+        );
+        return t;
+    }
+} // namespace
+
+// Overloads for your known base types
+template <typename T>
+T* cast(ast::expression* expr) {
+    return cast_impl<T, ast::expression>(expr);
+}
+
+template <typename T>
+T* cast(ast::statement* stmt) {
+    return cast_impl<T, ast::statement>(stmt);
+}
+
+template <typename T>
+T* cast(ast::error::error* err) {
+    return cast_impl<T, ast::error::error>(err);
+}
 
 struct ParserFixture {
     std::stringstream input;