JS: Make getDocumentation handle chain assignments

Author: asger-semmle

javascript/ql/src/semmle/javascript/Expr.qll

@@ -55,6 +55,14 @@ class ExprOrType extends @exprortype, Documentable {
       exists(DotExpr dot | this = dot.getProperty() |
         result = dot.getDocumentation()
       )
+      or
+      exists(AssignExpr e | this = e.getRhs() |
+        result = e.getDocumentation()
+      )
+      or
+      exists(ParExpr p | this = p.getExpression() |
+        result = p.getDocumentation()
+      )
     )
   }
 

javascript/ql/test/query-tests/JSDoc/JSDocForNonExistentParameter/JSDocForNonExistentParameter.expected

@@ -1,2 +1,4 @@
 | tst.js:4:4:4:9 | @param | @param tag refers to non-existent parameter prameter. |
 | tst.js:12:4:12:9 | @param | @param tag refers to non-existent parameter sign. |
+| tst.js:51:4:51:9 | @param | @param tag refers to non-existent parameter opts. |
+| tst.js:57:4:57:9 | @param | @param tag refers to non-existent parameter opts. |

javascript/ql/test/query-tests/JSDoc/JSDocForNonExistentParameter/tst.js

@@ -45,4 +45,16 @@ function good3() {
     lastName = arguments[0];
   }
   return firstName + sep + lastName;
-}
+}
+
+/**
+ * @param {IncomingMessage} opts
+ */
+var Cookie = foo.bar = function Cookie(options) {
+}
+
+/**
+ * @param {IncomingMessage} opts
+ */
+Cookie2 = foo.bar2 = function Cookie2(options) {
+}