JS: Test with namespaces and their various imports/exports

Author: asgerf

javascript/ql/lib/semmle/javascript/internal/UnderlyingTypes.qll

@@ -61,12 +61,7 @@ module UnderlyingTypes {
     or
     exists(Node mid |
       nodeRefersToModule(mid, mod, qualifiedName) and
-      ValueFlow::step(mid, node) and
-      // avoid a lot of unnecessary tuples
-      not (
-        node instanceof Variable and
-        not node = any(LocalVarTypeAccess ac).getVariable() // needed for TypeofTypeExpr
-      )
+      ValueFlow::step(mid, node)
     )
     or
     exists(Node mid, string prefix, string step |

javascript/ql/test/library-tests/UnderlyingTypes/namespaceDecls.ts

@@ -0,0 +1,27 @@
+import Express = require('express');
+
+namespace A {
+    export import E = Express;
+}
+namespace B {
+    export import Q = A
+}
+namespace C {
+    import E = Express;
+    export const A = E;
+}
+
+function t1(x: A.E.Request) { // $ hasUnderlyingType='express'.Request
+}
+
+function t2(x: B.Q.E.Request) { // $ hasUnderlyingType='express'.Request
+}
+
+function t3(x: typeof Express) { // $ hasUnderlyingType='express'
+}
+
+function t4(x: typeof A.E) { // $ hasUnderlyingType='express'
+}
+
+function t5(x: typeof C.A) { // $ hasUnderlyingType='express'
+}