JS: Add test for missing type flow through generics

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

@@ -0,0 +1,46 @@
+import * as express from 'express';
+
+type Box1<T> = {
+    value: T;
+    other: string;
+};
+function t1(b: Box1<express.Request>) {
+    b.value; // $ MISSING: hasUnderlyingType='express'.Request
+    b.other;
+}
+
+interface Box2<T> {
+    value: T;
+    other: string;
+}
+function t2(b: Box2<express.Request>) {
+    b.value; // $ MISSING: hasUnderlyingType='express'.Request
+    b.other;
+}
+
+class Box3<T> {
+    value: T;
+    other: string;
+}
+function t3(b: Box3<express.Request>) {
+    b.value; // $ MISSING: hasUnderlyingType='express'.Request
+    b.other;
+}
+
+abstract class Box4<T> {
+    abstract getValue(): T;
+    abstract getOther(): string;
+}
+function t4(b: Box4<express.Request>) {
+    b.getValue(); // $ MISSING: hasUnderlyingType='express'.Request
+    b.getOther();
+}
+
+type Box5<T> = {
+    value: T & { blah: string };
+    other: string;
+};
+function t5(b: Box5<express.Request>) {
+    b.value; // $ MISSING: hasUnderlyingType='express'.Request
+    b.other;
+}