Add additional regression test

Author: ahejlsberg

tests/baselines/reference/circularIndexedAccessErrors.errors.txt

@@ -2,9 +2,11 @@ tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts(3,5): error T
 tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts(7,5): error TS2502: 'x' is referenced directly or indirectly in its own type annotation.
 tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts(19,5): error TS2502: 'x' is referenced directly or indirectly in its own type annotation.
 tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts(23,5): error TS2502: 'x' is referenced directly or indirectly in its own type annotation.
+tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts(38,24): error TS2313: Type parameter 'T' has a circular constraint.
+tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts(38,30): error TS2536: Type '"hello"' cannot be used to index type 'T'.
 
 
-==== tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts (4 errors) ====
+==== tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts (6 errors) ====
 
     type T1 = {
         x: T1["x"];  // Error
@@ -42,4 +44,18 @@ tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts(23,5): error
         x: this["y"];
         y: this["z"];
         z: this["x"];
-    }
+    }
+    
+    // Repro from #12627
+    
+    interface Foo {
+        hello: boolean;
+    }
+    
+    function foo<T extends Foo | T["hello"]>() {
+                           ~~~~~~~~~~~~~~~~
+!!! error TS2313: Type parameter 'T' has a circular constraint.
+                                 ~~~~~~~~~~
+!!! error TS2536: Type '"hello"' cannot be used to index type 'T'.
+    }
+    

tests/baselines/reference/circularIndexedAccessErrors.js

@@ -28,7 +28,17 @@ class C2 {
     x: this["y"];
     y: this["z"];
     z: this["x"];
-}
+}
+
+// Repro from #12627
+
+interface Foo {
+    hello: boolean;
+}
+
+function foo<T extends Foo | T["hello"]>() {
+}
+
 
 //// [circularIndexedAccessErrors.js]
 var x2x = x2.x;
@@ -42,6 +52,8 @@ var C2 = (function () {
     }
     return C2;
 }());
+function foo() {
+}
 
 
 //// [circularIndexedAccessErrors.d.ts]
@@ -68,3 +80,7 @@ declare class C2 {
     y: this["z"];
     z: this["x"];
 }
+interface Foo {
+    hello: boolean;
+}
+declare function foo<T extends Foo | T["hello"]>(): void;

tests/cases/conformance/types/keyof/circularIndexedAccessErrors.ts

@@ -28,4 +28,13 @@ class C2 {
     x: this["y"];
     y: this["z"];
     z: this["x"];
-}
+}
+
+// Repro from #12627
+
+interface Foo {
+    hello: boolean;
+}
+
+function foo<T extends Foo | T["hello"]>() {
+}