derivedGenericClassWithAny.ts(2,5): error TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor.
derivedGenericClassWithAny.ts(3,18): error TS2322: Type 'null' is not assignable to type 'T'.
  'T' could be instantiated with an arbitrary type which could be unrelated to 'null'.
derivedGenericClassWithAny.ts(5,9): error TS2322: Type 'null' is not assignable to type 'T'.
  'T' could be instantiated with an arbitrary type which could be unrelated to 'null'.
derivedGenericClassWithAny.ts(29,5): error TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor.
derivedGenericClassWithAny.ts(30,18): error TS2322: Type 'string' is not assignable to type 'T'.
  'string' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string'.
derivedGenericClassWithAny.ts(32,9): error TS2322: Type 'string' is not assignable to type 'T'.
  'string' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string'.
derivedGenericClassWithAny.ts(41,1): error TS2322: Type 'E<string>' is not assignable to type 'C<number>'.
  Types of property 'x' are incompatible.
    Type 'string' is not assignable to type 'number'.


==== derivedGenericClassWithAny.ts (7 errors) ====
    class C<T extends number> {
        x: T;
        ~
!!! error TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor.
        get X(): T { return null; }
                     ~~~~~~
!!! error TS2322: Type 'null' is not assignable to type 'T'.
!!! error TS2322:   'T' could be instantiated with an arbitrary type which could be unrelated to 'null'.
        foo(): T {
            return null;
            ~~~~~~
!!! error TS2322: Type 'null' is not assignable to type 'T'.
!!! error TS2322:   'T' could be instantiated with an arbitrary type which could be unrelated to 'null'.
        }
    }
    
    class D extends C<number> {
        x: any;
        get X(): any {
            return null;
        }
        foo(): any {
            return 1;
        }
    
        static y: any;
        static get Y(): any {
            return null;
        }
        static bar(): any {
            return null;
        }
    }
    
    // if D is a valid class definition than E is now not safe tranisitively through C
    class E<T extends string> extends D {
        x: T;
        ~
!!! error TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor.
        get X(): T { return ''; } // error
                     ~~~~~~
!!! error TS2322: Type 'string' is not assignable to type 'T'.
!!! error TS2322:   'string' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string'.
        foo(): T {
            return ''; // error
            ~~~~~~
!!! error TS2322: Type 'string' is not assignable to type 'T'.
!!! error TS2322:   'string' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string'.
        }
    }
    
    declare var c: C<number>;
    declare var d: D;
    declare var e: E<string>;
    
    c = d;
    c = e;
    ~
!!! error TS2322: Type 'E<string>' is not assignable to type 'C<number>'.
!!! error TS2322:   Types of property 'x' are incompatible.
!!! error TS2322:     Type 'string' is not assignable to type 'number'.
    var r = c.foo(); // e.foo would return string