Class Mixin in TypeScript with `instanceof` override

README.md

Example

class Person {
  name!: string
  age!: number

  private gender!: "aircraft"
}

class Profile {
  name!: string
  avatar!: string

  protected something!: {}
}

export class User extends mixin(Person, Profile) {
  id!: number

  asd() {
    this.gender // => Error: Property is private
    this.something
  }
}


const user = new User
user.gender // => Error: Property is private
user.something // => Error: Property is protected

user instanceof User // === true
user instanceof Person // === true
user instanceof Profile // === true
user instanceof mixin(Person, Profile) // === true

Example Notes

• a mixin class can define public/protected/private property visibility.
• a mixin class can't define a constructor
• mixin classes must match or error will be shown at mixin(Person, Profile).
• a class that extends a mixin can be checked with instanceof for each class and altogether.

Type per class

When inspecting a property from a mixin, your IDE will display what this type belongs to.

Type super

When inspecting super, your IDE will display the mixins.