JS: Add hanging test case

Author: asgerf

javascript/ql/test/library-tests/TypeScript/RegressionTests/GenericTypeAlias/test.ql

@@ -0,0 +1,8 @@
+import javascript
+
+// The extractor would hang on this test case, it doesn't matter too much what the output of the test is.
+query TypeAliasDeclaration typeAliases() { any() }
+
+query Type typeAliasType(TypeAliasDeclaration decl) { result = decl.getTypeName().getType() }
+
+query Type getAliasedType(TypeAliasReference ref) { result = ref.getAliasedType() }

javascript/ql/test/library-tests/TypeScript/RegressionTests/GenericTypeAlias/tsconfig.json

@@ -0,0 +1,3 @@
+{
+    "include": ["."]
+}

javascript/ql/test/library-tests/TypeScript/RegressionTests/GenericTypeAlias/tst.ts

@@ -0,0 +1,5 @@
+export type Foo<R> = <A>() => Foo<R | A>;
+
+export type Bar<R> = <A>() => Bar<[R, A]>;
+
+export type Baz<R> = <A>() => Baz<(x: R) => A>;