tests/cases/conformance/types/typeRelationships/assignmentCompatibility/covariantCallbacks.ts(12,5): error TS2322: Type 'P<A>' is not assignable to type 'P<B>'.
  Type 'A' is not assignable to type 'B'.
    Property 'b' is missing in type 'A'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/covariantCallbacks.ts(17,5): error TS2322: Type 'Promise<A>' is not assignable to type 'Promise<B>'.
  Type 'A' is not assignable to type 'B'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/covariantCallbacks.ts(30,5): error TS2322: Type 'AList1' is not assignable to type 'BList1'.
  Types of property 'forEach' are incompatible.
    Type '(cb: (item: A) => void) => void' is not assignable to type '(cb: (item: B) => void) => void'.
      Types of parameters 'cb' and 'cb' are incompatible.
        Types of parameters 'item' and 'item' are incompatible.
          Type 'A' is not assignable to type 'B'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/covariantCallbacks.ts(43,5): error TS2322: Type 'AList2' is not assignable to type 'BList2'.
  Types of property 'forEach' are incompatible.
    Type '(cb: (item: A) => boolean) => void' is not assignable to type '(cb: (item: A) => void) => void'.
      Types of parameters 'cb' and 'cb' are incompatible.
        Type 'void' is not assignable to type 'boolean'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/covariantCallbacks.ts(56,5): error TS2322: Type 'AList3' is not assignable to type 'BList3'.
  Types of property 'forEach' are incompatible.
    Type '(cb: (item: A) => void) => void' is not assignable to type '(cb: (item: A, context: any) => void) => void'.
      Types of parameters 'cb' and 'cb' are incompatible.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/covariantCallbacks.ts(69,5): error TS2322: Type 'AList4' is not assignable to type 'BList4'.
  Types of property 'forEach' are incompatible.
    Type '(cb: (item: A) => A) => void' is not assignable to type '(cb: (item: B) => B) => void'.
      Types of parameters 'cb' and 'cb' are incompatible.
        Types of parameters 'item' and 'item' are incompatible.
          Type 'A' is not assignable to type 'B'.


==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/covariantCallbacks.ts (6 errors) ====
    // Test that callback parameters are related covariantly
    
    interface P<T> {
        then(cb: (value: T) => void): void;
    };
    
    interface A { a: string }
    interface B extends A { b: string }
    
    function f1(a: P<A>, b: P<B>) {
        a = b;
        b = a;  // Error
        ~
!!! error TS2322: Type 'P<A>' is not assignable to type 'P<B>'.
!!! error TS2322:   Type 'A' is not assignable to type 'B'.
!!! error TS2322:     Property 'b' is missing in type 'A'.
    }
    
    function f2(a: Promise<A>, b: Promise<B>) {
        a = b;
        b = a;  // Error
        ~
!!! error TS2322: Type 'Promise<A>' is not assignable to type 'Promise<B>'.
!!! error TS2322:   Type 'A' is not assignable to type 'B'.
    }
    
    interface AList1 {
        forEach(cb: (item: A) => void): void;
    }
    
    interface BList1 {
        forEach(cb: (item: B) => void): void;
    }
    
    function f11(a: AList1, b: BList1) {
        a = b;
        b = a;  // Error
        ~
!!! error TS2322: Type 'AList1' is not assignable to type 'BList1'.
!!! error TS2322:   Types of property 'forEach' are incompatible.
!!! error TS2322:     Type '(cb: (item: A) => void) => void' is not assignable to type '(cb: (item: B) => void) => void'.
!!! error TS2322:       Types of parameters 'cb' and 'cb' are incompatible.
!!! error TS2322:         Types of parameters 'item' and 'item' are incompatible.
!!! error TS2322:           Type 'A' is not assignable to type 'B'.
    }
    
    interface AList2 {
        forEach(cb: (item: A) => boolean): void;
    }
    
    interface BList2 {
        forEach(cb: (item: A) => void): void;
    }
    
    function f12(a: AList2, b: BList2) {
        a = b;
        b = a;  // Error
        ~
!!! error TS2322: Type 'AList2' is not assignable to type 'BList2'.
!!! error TS2322:   Types of property 'forEach' are incompatible.
!!! error TS2322:     Type '(cb: (item: A) => boolean) => void' is not assignable to type '(cb: (item: A) => void) => void'.
!!! error TS2322:       Types of parameters 'cb' and 'cb' are incompatible.
!!! error TS2322:         Type 'void' is not assignable to type 'boolean'.
    }
    
    interface AList3 {
        forEach(cb: (item: A) => void): void;
    }
    
    interface BList3 {
        forEach(cb: (item: A, context: any) => void): void;
    }
    
    function f13(a: AList3, b: BList3) {
        a = b;
        b = a;  // Error
        ~
!!! error TS2322: Type 'AList3' is not assignable to type 'BList3'.
!!! error TS2322:   Types of property 'forEach' are incompatible.
!!! error TS2322:     Type '(cb: (item: A) => void) => void' is not assignable to type '(cb: (item: A, context: any) => void) => void'.
!!! error TS2322:       Types of parameters 'cb' and 'cb' are incompatible.
    }
    
    interface AList4 {
        forEach(cb: (item: A) => A): void;
    }
    
    interface BList4 {
        forEach(cb: (item: B) => B): void;
    }
    
    function f14(a: AList4, b: BList4) {
        a = b;
        b = a;  // Error
        ~
!!! error TS2322: Type 'AList4' is not assignable to type 'BList4'.
!!! error TS2322:   Types of property 'forEach' are incompatible.
!!! error TS2322:     Type '(cb: (item: A) => A) => void' is not assignable to type '(cb: (item: B) => B) => void'.
!!! error TS2322:       Types of parameters 'cb' and 'cb' are incompatible.
!!! error TS2322:         Types of parameters 'item' and 'item' are incompatible.
!!! error TS2322:           Type 'A' is not assignable to type 'B'.
    }
    