Prevents errors that occur when calling a non-existent JavaScript property with a question mark

Author: ledsun

packages/gems/js/lib/js.rb

@@ -173,11 +173,15 @@ def method_missing(sym, *args, &block)
     if sym_str.end_with?("?")
       # When a JS method is called with a ? suffix, it is treated as a predicate method,
       # and the return value is converted to a Ruby boolean value automatically.
-      result = self.call(sym_str[0..-2].to_sym, *args, &block)
-
-      # Type coerce the result to boolean type
-      # to match the true/false determination in JavaScript's if statement.
-      JS.global.Boolean(result) == JS::True
+      sym = sym_str[0..-2].to_sym
+      if self[sym].typeof == "function"
+        result = self.call(sym, *args, &block)
+        # Type coerce the result to boolean type
+        # to match the true/false determination in JavaScript's if statement.
+        JS.global.Boolean(result) == JS::True
+      else
+        false
+      end
     elsif self[sym].typeof == "function"
       self.call(sym, *args, &block)
     else

packages/npm-packages/ruby-wasm-wasi/test/unit/test_object.rb

@@ -324,7 +324,8 @@ def test_method_missing_with_?
         return_false() { return false; },
         return_object() { return {}; },
         return_null() { return null; },
-        return_empty_string() { return ''; }
+        return_empty_string() { return ''; },
+        return_number: 42
       };
     JS
 
@@ -342,6 +343,12 @@ def test_method_missing_with_?
     # Return Ruby false when the return value is JavaScript false
     assert_false object.return_null?
     assert_false object.return_empty_string?
+
+    # Return false when the property is not a function
+    assert_false object.return_number?
+
+    # Return false when function is not defined
+    assert_false object.undefined?
   end
 
   def test_respond_to_missing?