Add regression test

ahejlsberg · ahejlsberg · commit 2fd4aaee92a1 · 2019-05-22T06:54:16.000-07:00
diff --git a/tests/cases/conformance/types/keyof/keyofAndIndexedAccess2.ts b/tests/cases/conformance/types/keyof/keyofAndIndexedAccess2.ts
@@ -147,3 +147,13 @@ export class c {
     this["a"] = "b";
   }
 }
+
+// Repro from #31385
+
+type Foo<T> = { [key: string]: { [K in keyof T]: K }[keyof T] };
+
+type Bar<T> = { [key: string]: { [K in keyof T]: [K] }[keyof T] };
+
+type Baz<T, Q extends Foo<T>> = { [K in keyof Q]: T[Q[K]] };
+
+type Qux<T, Q extends Bar<T>> = { [K in keyof Q]: T[Q[K]["0"]] };

Original file line number	Diff line number	Diff line change
`@@ -147,3 +147,13 @@ export class c {`
`147`	`147`	`this["a"] = "b";`
`148`	`148`	`}`
`149`	`149`	`}`
	`150`	`+`
	`151`	`+// Repro from #31385`
	`152`	`+`
	`153`	`+type Foo<T> = { [key: string]: { [K in keyof T]: K }[keyof T] };`
	`154`	`+`
	`155`	`+type Bar<T> = { [key: string]: { [K in keyof T]: [K] }[keyof T] };`
	`156`	`+`
	`157`	`+type Baz<T, Q extends Foo<T>> = { [K in keyof Q]: T[Q[K]] };`
	`158`	`+`
	`159`	`+type Qux<T, Q extends Bar<T>> = { [K in keyof Q]: T[Q[K]["0"]] };`