75 lines
2.4 KiB
Text
75 lines
2.4 KiB
Text
|
==== tests/cases/conformance/types/typeRelationships/recursiveTypes/objectTypeWithRecursiveWrappedPropertyCheckedNominally.ts (9 errors) ====
|
||
|
// Types with infinitely expanding recursive types are type checked nominally
|
||
|
|
||
|
class List<T> {
|
||
|
data: T;
|
||
|
next: List<List<T>>;
|
||
|
}
|
||
|
|
||
|
class MyList<T> {
|
||
|
data: T;
|
||
|
next: MyList<MyList<T>>;
|
||
|
}
|
||
|
|
||
|
var list1 = new List<number>();
|
||
|
var list2 = new List<string>();
|
||
|
|
||
|
var myList1 = new MyList<number>();
|
||
|
var myList2 = new MyList<string>();
|
||
|
|
||
|
list1 = myList1; // error, not nominally equal
|
||
|
list1 = myList2; // error, type mismatch
|
||
|
~~~~~
|
||
|
!!! Type 'MyList<string>' is not assignable to type 'List<number>':
|
||
|
!!! Types of property 'data' are incompatible:
|
||
|
!!! Type 'string' is not assignable to type 'number'.
|
||
|
|
||
|
list2 = myList1; // error, not nominally equal
|
||
|
~~~~~
|
||
|
!!! Type 'MyList<number>' is not assignable to type 'List<string>':
|
||
|
!!! Types of property 'data' are incompatible:
|
||
|
!!! Type 'number' is not assignable to type 'string'.
|
||
|
list2 = myList2; // error, type mismatch
|
||
|
|
||
|
var rList1 = new List<List<number>>();
|
||
|
var rMyList1 = new List<MyList<number>>();
|
||
|
rList1 = rMyList1; // error, not nominally equal
|
||
|
|
||
|
function foo<T extends List<number>, U extends MyList<number>>(t: T, u: U) {
|
||
|
t = u; // error
|
||
|
~
|
||
|
!!! Type 'U' is not assignable to type 'T'.
|
||
|
u = t; // error
|
||
|
~
|
||
|
!!! Type 'T' is not assignable to type 'U'.
|
||
|
|
||
|
var a: List<number>;
|
||
|
var b: MyList<number>;
|
||
|
a = t; // ok
|
||
|
a = u; // error
|
||
|
b = t; // error
|
||
|
b = u; // ok
|
||
|
}
|
||
|
|
||
|
function foo2<T extends U, U extends MyList<number>>(t: T, u: U) {
|
||
|
~~~~~~~~~~~
|
||
|
!!! Constraint of a type parameter cannot reference any type parameter from the same type parameter list.
|
||
|
t = u; // error
|
||
|
~
|
||
|
!!! Type 'U' is not assignable to type 'T'.
|
||
|
u = t; // was error, ok after constraint made illegal, doesn't matter
|
||
|
~
|
||
|
!!! Type 'T' is not assignable to type 'U'.
|
||
|
|
||
|
var a: List<number>;
|
||
|
var b: MyList<number>;
|
||
|
|
||
|
a = t; // error
|
||
|
~
|
||
|
!!! Type 'T' is not assignable to type 'List<number>'.
|
||
|
a = u; // error
|
||
|
b = t; // ok
|
||
|
~
|
||
|
!!! Type 'T' is not assignable to type 'MyList<number>'.
|
||
|
b = u; // ok
|
||
|
}
|