Add regression test

ahejlsberg · ahejlsberg · commit 238177657fcd · 2018-05-08T09:42:21.000-07:00
diff --git a/tests/cases/conformance/types/keyof/keyofAndIndexedAccess.ts b/tests/cases/conformance/types/keyof/keyofAndIndexedAccess.ts
@@ -629,3 +629,11 @@ class Unbounded<T> {
         let y: {} | undefined | null = x;
     }
 }
+
+// Repro from #23940
+
+interface I7 {
+    x: any;
+}
+type Foo7<T extends number> = T;
+declare function f7<K extends keyof I7>(type: K): Foo7<I7[K]>;

Original file line number	Diff line number	Diff line change
`@@ -629,3 +629,11 @@ class Unbounded<T> {`
`629`	`629`	`let y: {} \| undefined \| null = x;`
`630`	`630`	`}`
`631`	`631`	`}`
	`632`	`+`
	`633`	`+// Repro from #23940`
	`634`	`+`
	`635`	`+interface I7 {`
	`636`	`+ x: any;`
	`637`	`+}`
	`638`	`+type Foo7<T extends number> = T;`
	`639`	`+declare function f7<K extends keyof I7>(type: K): Foo7<I7[K]>;`