multi-inheritance.ts

/*
attempts to implement this

class A {
  property num

  method test() {
    print("A")
  }
}

class B {
  property num

  method test() {
    print("B")
  }
}

class C extends A, B {
  property num
  
  method test() {
    super.A.test()
    super.B.test()
    print("C")
  }
}

new C().test()
*/

interface MultiInheritableClass {
  __parents: { [key: string]: MultiInheritableClass }
}

class A implements MultiInheritableClass {
  __parents = {}

  num = 0

  test() {
    return A_test(this)
  }
}

class B implements MultiInheritableClass {
  __parents = {}

  num = 1

  test() {
    return B_test(this)
  }
}

// class C extends A, B
class C implements MultiInheritableClass {
  __parents = { A: new A, B: new B }

  // .num must be defined because both A, B have a .num
  num = 0

  // same goes for this function
  test() {
    // Must pass by explicit reference, cannot spread
    return C_test(this, this.__parents.A, this.__parents.B)
  }
}

function C_test(thisRef: C, refA: A, refB: B) {
  refA.test()
  refB.test()

  // Editing properties also works
  refA.num++

  console.log(refA.num)

  console.log("C")
}

function B_test(thisRef: B) {
  console.log("B")
}

function A_test(thisRef: A) {
  console.log("A")
}

new C().test()