Add a test to make sure types are being checked for privates

Author: JsonFreeman

src/compiler/checker.ts

@@ -4340,7 +4340,7 @@ module ts {
                 var widenedType = getWidenedType(exprType, /*supressNoImplicitAnyErrors*/ true);
                 if (!(isTypeAssignableTo(targetType, widenedType))) {
                     checkTypeAssignableTo(exprType, targetType, node, Diagnostics.Neither_type_0_nor_type_1_is_assignable_to_the_other_Colon, Diagnostics.Neither_type_0_nor_type_1_is_assignable_to_the_other);
-                } 
+                }
             }
             return targetType;
         }

tests/baselines/reference/objectTypesIdentityWithPrivates3.errors.txt

@@ -0,0 +1,29 @@
+==== tests/cases/conformance/types/typeRelationships/typeAndMemberIdentity/objectTypesIdentityWithPrivates3.ts (1 errors) ====
+    interface T1 { }
+    interface T2 { z }
+    
+    class C1<T> {
+        private x;
+    }
+    
+    class C2 extends C1<T1> {
+        y;
+    }
+    
+    var c1: C1<T2>;
+    <C2>c1; // Should succeed (private x originates in the same declaration)
+    
+    
+    class C3<T> {
+        private x: T; // This T is the difference between C3 and C1
+    }
+    
+    class C4 extends C3<T1> {
+        y;
+    }
+    
+    var c3: C3<T2>;
+    <C4>c3; // Should fail (private x originates in the same declaration, but different types)
+    ~~~~~~
+!!! Neither type 'C3<T2>' nor type 'C4' is assignable to the other:
+!!!   Property 'y' is missing in type 'C3<T2>'.

tests/baselines/reference/objectTypesIdentityWithPrivates3.js

@@ -11,7 +11,19 @@ class C2 extends C1<T1> {
 }
 
 var c1: C1<T2>;
-<C2>c1; // Should succeed (private x originates in the same declaration)
+<C2>c1; // Should succeed (private x originates in the same declaration)
+
+
+class C3<T> {
+    private x: T; // This T is the difference between C3 and C1
+}
+
+class C4 extends C3<T1> {
+    y;
+}
+
+var c3: C3<T2>;
+<C4>c3; // Should fail (private x originates in the same declaration, but different types)
 
 //// [objectTypesIdentityWithPrivates3.js]
 var __extends = this.__extends || function (d, b) {
@@ -34,3 +46,17 @@ var C2 = (function (_super) {
 })(C1);
 var c1;
 c1; // Should succeed (private x originates in the same declaration)
+var C3 = (function () {
+    function C3() {
+    }
+    return C3;
+})();
+var C4 = (function (_super) {
+    __extends(C4, _super);
+    function C4() {
+        _super.apply(this, arguments);
+    }
+    return C4;
+})(C3);
+var c3;
+c3; // Should fail (private x originates in the same declaration, but different types)

tests/baselines/reference/objectTypesIdentityWithPrivates3.types

@@ -10,4 +10,16 @@ class C2 extends C1<T1> {
 }
 
 var c1: C1<T2>;
-<C2>c1; // Should succeed (private x originates in the same declaration)
+<C2>c1; // Should succeed (private x originates in the same declaration)
+
+
+class C3<T> {
+    private x: T; // This T is the difference between C3 and C1
+}
+
+class C4 extends C3<T1> {
+    y;
+}
+
+var c3: C3<T2>;
+<C4>c3; // Should fail (private x originates in the same declaration, but different types)