forward toString() etc. predicates from YamlNode to Locatable

Author: erik-krogh

javascript/ql/lib/semmle/javascript/PrintAst.qll

@@ -51,7 +51,7 @@ private predicate isNotNeeded(Locatable el) {
 private string getQlClass(Locatable el) {
   result = "[" + el.getPrimaryQlClasses() + "] "
   // Alternative implementation -- do not delete. It is useful for QL class discovery.
-  // not el.getAPrimaryQlClass() = "???" and result = "[" + getPrimaryQlClasses() + "] " or el.getAPrimaryQlClass() = "???" and result = "??[" + concat(el.getAQlClass(), ",") + "] "
+  // not el.getAPrimaryQlClass() = "???" and result = "[" + el.getPrimaryQlClasses() + "] " or el.getAPrimaryQlClass() = "???" and result = "??[" + concat(el.getAQlClass(), ",") + "] "
 }
 
 /**

javascript/ql/lib/semmle/javascript/YAML.qll

@@ -48,6 +48,15 @@ private module YamlSig implements LibYaml::InputSig {
 
 import LibYaml::Make<YamlSig>
 
+// private class to forward the `toString` etc. predicates from `YamlNode` to `Locatable`.
+private class MyYmlNode extends Locatable instanceof YamlNode {
+  override string getAPrimaryQlClass() { result = YamlNode.super.getAPrimaryQlClass() }
+
+  override Location getLocation() { result = YamlNode.super.getLocation() }
+
+  override string toString() { result = YamlNode.super.toString() }
+}
+
 /** DEPRECATED: Alias for YamlNode */
 deprecated class YAMLNode = YamlNode;