Add regression test

ahejlsberg · ahejlsberg · commit 34b4dbb26000 · 2017-01-30T15:47:18.000-08:00
diff --git a/tests/cases/conformance/types/keyof/keyofAndIndexedAccess.ts b/tests/cases/conformance/types/keyof/keyofAndIndexedAccess.ts
@@ -517,3 +517,13 @@ class B extends A<{ x: number}> {
 		p.x;
 	}
 }
+
+// Repro from #13749
+
+class Form<T> {
+    private childFormFactories: {[K in keyof T]: (v: T[K]) => Form<T[K]>}
+
+    public set<K extends keyof T>(prop: K, value: T[K]) {
+        this.childFormFactories[prop](value)
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -517,3 +517,13 @@ class B extends A<{ x: number}> {`
`517`	`517`	`p.x;`
`518`	`518`	`}`
`519`	`519`	`}`
	`520`	`+`
	`521`	`+// Repro from #13749`
	`522`	`+`
	`523`	`+class Form<T> {`
	`524`	`+ private childFormFactories: {[K in keyof T]: (v: T[K]) => Form<T[K]>}`
	`525`	`+`
	`526`	`+ public set<K extends keyof T>(prop: K, value: T[K]) {`
	`527`	`+ this.childFormFactories[prop](value)`
	`528`	`+ }`
	`529`	`+}`