Add regression tests

Author: ahejlsberg

tests/cases/conformance/types/mapped/recursiveMappedTypes.ts

@@ -22,3 +22,42 @@ type tup = [number, number, number, number];
 function foo(arg: Circular<tup>): tup {
   return arg;
 }
+
+// Repro from #29442
+
+type DeepMap<T extends unknown[], R> = {
+  [K in keyof T]: T[K] extends unknown[] ? DeepMap<T[K], R> : R;
+};
+
+type tpl = [string, [string, [string]]];
+type arr = string[][];
+
+type t1 = DeepMap<tpl, number>;  // [number, [number, [number]]]
+type t2 = DeepMap<arr, number>;  // number[][]
+
+// Repro from #29577
+
+type Transform<T> = { [K in keyof T]: Transform<T[K]> };
+
+interface User {
+    avatar: string;
+}
+
+interface Guest {
+    displayName: string;
+}
+
+interface Product {
+    users: (User | Guest)[];
+}
+
+declare var product: Transform<Product>;
+product.users;  // (Transform<User> | Transform<Guest>)[]
+
+// Repro from #29702
+
+type Remap1<T> = { [P in keyof T]: Remap1<T[P]>; };
+type Remap2<T> = T extends object ? { [P in keyof T]: Remap2<T[P]>; } : T;
+  
+type a = Remap1<string[]>;  // string[]
+type b = Remap2<string[]>;  // string[]