type Source1 = { array: Source2[] };
type Source2 = { array: Source3[] };
type Source3 = { array: Source4[] };
type Source4 = {};

// same as Source types but with "someNewProperty"
type Target1 = {
  array: Target2[];
  // someNewProperty: string // error in target1 assignment as expected if enabled
};
type Target2 = {
  array: Target3[];
  // someNewProperty: string // error in target1 assignment as expected if enabled
};
type Target3 = {
  array: Target4[];
  // someNewProperty: string // error in target1 assignment as expected if enabled
};
type Target4 = {
  someNewProperty: string; // not existing in Source4 => no error in target1 assignment
};

declare const source1: Source1;
declare const source2: Source2;
declare const source3: Source3;
declare const source4: Source4;

// this should not compile:
const target1: Target1 = source1; // comment this line to get errors in target2, target3 assignments or move this line after target2 assignment

// this should not compile:
const target2: Target2 = source2; // error if target1 assignment is commented or after this assignment

// this should not compile:
const target3: Target3 = source3; // error if target1 assignment is commented or after target2 assignment

// does not compile:
const target4: Target4 = source4; // error as expected

/*
PS:
- same (wrong) behavior with interfaces and classes
*/