Add guard for visitor functions preventing from cryptic errors due to…

… incomplete visitors
Mingun · Jan 17, 2018 · f29e1ea · f29e1ea
1 parent 4037a86
commit f29e1ea
Showing 1 changed file with 10 additions and 1 deletion.
diff --git a/lib/compiler/visitor.js b/lib/compiler/visitor.js
@@ -4,7 +4,16 @@
 let visitor = {
   build(functions) {
     function visit(node) {
-      return functions[node.type].apply(null, arguments);
+      if (!node) {
+        throw new Error("`Visitor function called with no or `null` node");
+      }
+
+      let func = functions[node.type];
+      if (!func) {
+        throw new Error("Visitor function for node type '" + node.type + " not defined");
+      }
+
+      return func.apply(null, arguments);
     }
 
     function visitNop() {